Seed is the basic input for crop production and modern plant breeding has played a key role in developing high-yielding varieties and hybrids. Good quality seeds of improved varieties can increase production by 20-25%. A seed consists of an embryonic plant surrounded by food and a protective coat. It completes the plant reproduction process. Seed technology aims to rapidly multiply popular varieties and ensure a timely supply of high quality seeds at reasonable prices. It maintains genetic purity and certification standards. The seed industry has increased India's food production and plays a critical role in agriculture.
Seed storage involves preserving seeds with their initial quality from harvest until planting. There are different stages of storage from when seeds reach maturity on the plant until they are planted. The main objectives of storage are to maintain seed germination, purity, and vigor by providing suitable storage conditions. Key factors that influence seed longevity during storage include moisture content, temperature, humidity, pests, and the genetic characteristics of the seeds. Proper storage requires dry, cool conditions with pest control and high-quality seeds.
The document discusses seed sampling and testing procedures. It explains that obtaining a representative sample is crucial, as test results can only reflect the quality of the sample. It describes different types of samples taken from a seed lot, including primary samples, composite samples, submitted samples, and working samples. The document outlines equipment and methods used for sampling, including deep bin samplers, triers, and hand sampling. It discusses dividing samples for testing in the laboratory and storing samples. Finally, it summarizes seed testing objectives and procedures, including receiving samples, moisture testing, preparing working samples, conducting routine tests, and maintaining records.
Temperate fruit plants are those that grow in climates with distinct winter cold periods. They require chilling temperatures to break dormancy and initiate growth. Examples include apple, pear, stone fruits, berries, nuts, and cherries. These plants are classified based on factors like plant structure, fruit morphology, bearing habit, and growth pattern. Fruits are categorized as tree fruits, small fruits, or nuts. Classification helps identify relationships and suggest cultural requirements. Common temperate fruit types include pomes like apple; drupes like peach; and dry fruits like nuts.
The document discusses genetic principles of seed production and certification. It explains that varieties can deteriorate due to developmental variations, mechanical mixtures, mutations, natural crossing, minor genetic variations, diseases, and improper techniques. Seed production and certification aims to maintain genetic purity and prevent such deterioration. It involves controlling the seed source, isolation distances, rouging fields, and certification of seeds in classes from breeder to foundation to registered to certified.
This document discusses different types of seed storage. It describes bag storage which uses waterproof warehouses and follows sanitation practices. Bulk storage also meets basic requirements but requires more insulation. Seeds stored in bulk need frequent turning to prevent deterioration. Conditioned storage carefully controls temperature and humidity but is costly. Cryogenic storage places seeds in liquid nitrogen at -196°C for long-term preservation. Hermetic storage seals seeds in air-tight containers. Containerized storage uses desiccants to regulate humidity in closed containers. The document concludes by outlining preferred long-term storage conditions of -18°C or less in air-tight containers at 3-7% moisture.
The document discusses the stages of seed development from formation of reproductive organs to maturation. It describes the processes of megasporogenesis and megagametogenesis, microsporogenesis and microgametogenesis which lead to the development of embryo sac and pollen grains. Pollination and fertilization occur, followed by embryogenesis and storage tissue formation as starch, fat, and proteins are deposited in the developing seed. Proper nutrition and irrigation are important for seed development and maturity is reached when seeds reach maximum dry weight and viability. Harvesting before or after physiological maturity can impact seed quality and storage potential.
Seed is the basic input for crop production and modern plant breeding has played a key role in developing high-yielding varieties and hybrids. Good quality seeds of improved varieties can increase production by 20-25%. A seed consists of an embryonic plant surrounded by food and a protective coat. It completes the plant reproduction process. Seed technology aims to rapidly multiply popular varieties and ensure a timely supply of high quality seeds at reasonable prices. It maintains genetic purity and certification standards. The seed industry has increased India's food production and plays a critical role in agriculture.
Seed storage involves preserving seeds with their initial quality from harvest until planting. There are different stages of storage from when seeds reach maturity on the plant until they are planted. The main objectives of storage are to maintain seed germination, purity, and vigor by providing suitable storage conditions. Key factors that influence seed longevity during storage include moisture content, temperature, humidity, pests, and the genetic characteristics of the seeds. Proper storage requires dry, cool conditions with pest control and high-quality seeds.
The document discusses seed sampling and testing procedures. It explains that obtaining a representative sample is crucial, as test results can only reflect the quality of the sample. It describes different types of samples taken from a seed lot, including primary samples, composite samples, submitted samples, and working samples. The document outlines equipment and methods used for sampling, including deep bin samplers, triers, and hand sampling. It discusses dividing samples for testing in the laboratory and storing samples. Finally, it summarizes seed testing objectives and procedures, including receiving samples, moisture testing, preparing working samples, conducting routine tests, and maintaining records.
Temperate fruit plants are those that grow in climates with distinct winter cold periods. They require chilling temperatures to break dormancy and initiate growth. Examples include apple, pear, stone fruits, berries, nuts, and cherries. These plants are classified based on factors like plant structure, fruit morphology, bearing habit, and growth pattern. Fruits are categorized as tree fruits, small fruits, or nuts. Classification helps identify relationships and suggest cultural requirements. Common temperate fruit types include pomes like apple; drupes like peach; and dry fruits like nuts.
The document discusses genetic principles of seed production and certification. It explains that varieties can deteriorate due to developmental variations, mechanical mixtures, mutations, natural crossing, minor genetic variations, diseases, and improper techniques. Seed production and certification aims to maintain genetic purity and prevent such deterioration. It involves controlling the seed source, isolation distances, rouging fields, and certification of seeds in classes from breeder to foundation to registered to certified.
This document discusses different types of seed storage. It describes bag storage which uses waterproof warehouses and follows sanitation practices. Bulk storage also meets basic requirements but requires more insulation. Seeds stored in bulk need frequent turning to prevent deterioration. Conditioned storage carefully controls temperature and humidity but is costly. Cryogenic storage places seeds in liquid nitrogen at -196°C for long-term preservation. Hermetic storage seals seeds in air-tight containers. Containerized storage uses desiccants to regulate humidity in closed containers. The document concludes by outlining preferred long-term storage conditions of -18°C or less in air-tight containers at 3-7% moisture.
The document discusses the stages of seed development from formation of reproductive organs to maturation. It describes the processes of megasporogenesis and megagametogenesis, microsporogenesis and microgametogenesis which lead to the development of embryo sac and pollen grains. Pollination and fertilization occur, followed by embryogenesis and storage tissue formation as starch, fat, and proteins are deposited in the developing seed. Proper nutrition and irrigation are important for seed development and maturity is reached when seeds reach maximum dry weight and viability. Harvesting before or after physiological maturity can impact seed quality and storage potential.
Introduction to seed and seed technologyNSStudents
The Presentation is prepared by the N.S Institution of science, Markapur.
It consists of a basic introduction related to Introduction to seed and seed technology.
Seed quality is determined by physical, physiological, genetic, and storability characteristics. Maintaining genetic purity during seed production requires controlling the seed source, isolation distances, rouging fields, certification, and grow-out tests. Key steps in quality seed production include selecting suitable regions and seed plots, proper land preparation, recommended varieties, treatments, planting methods, weed/pest control, irrigation, and timely harvesting and drying. This ensures high-quality seeds that perform well and retain desirable traits.
General principles of seed production Junaid Abbas
The document discusses the importance of producing high quality pedigree seed through maintaining genetic purity and varietal characteristics. It states that seed production requires strict attention, high technical skills, and financial investment. Several factors can lead to the deterioration of seed varieties during production cycles, such as developmental variations due to different environmental conditions, mechanical mixtures during sowing and harvesting, natural crossing through pollination, and mutations. The document provides guidelines for maintaining varietal purity through practices like inspection of seed fields, rouging of off-type plants, adequate isolation distances, and periodic testing to ensure genetic purity is preserved in seed production.
Seed vigour is determined by the properties that allow seeds to germinate and grow in different environments. It is affected by both internal factors, like genotype and seed size, and external factors such as mechanical injury during harvesting, pre-harvesting conditions, soil temperature and moisture, tillage and fertilizer use, and moisture uptake. Smaller seeds tend to be less vigorous than medium or large seeds. Harvesting seeds before maturity and mechanical damage during harvesting can reduce seed vigour by allowing pathogens to enter seeds. High soil moisture and temperature during seed development and storage can increase respiration and pathogen growth, shortening storage life. Tillage and adequate fertilizer promote seed yield and vigour.
This document discusses best practices for maintaining genetic purity and quality in seed production. It identifies seven main causes of variety deterioration: developmental variation, mechanical mixture, mutation, natural crossing, minor genetic variation, influence of diseases, and issues from plant breeding techniques. Key recommendations include growing seeds in adapted regions, rogueing fields to remove off-type plants, providing adequate isolation between varieties, and certifying seeds according to generation to limit deterioration to four generations. Proper agronomic practices like seed treatment, isolation, and weed control are also important to maintain high quality seeds.
The document discusses various tests used to assess seed viability and vigor, including warm germination tests, tetrazolium tests, growth tests, and stress tests. The warm germination test is the standard test to assess viability by germinating seeds in ideal conditions. Tetrazolium tests use chemicals to determine potential germination. Growth tests measure speed and size of seedling growth. Stress tests like cold tests and accelerated aging expose seeds to stressful conditions to evaluate vigor. Proper testing helps farmers make management decisions about seeding rates and avoiding weeds.
This document discusses seed deterioration, including its definition, types, characteristics, factors, and methods for testing. Seed deterioration is defined as the irreversible loss of seed quality, viability, and vigor over time due to environmental factors. There are three main types of deterioration: field weathering during seed maturation, harvest and post-harvest deterioration from mechanical damage, and storage deterioration from high temperature and moisture levels. Characteristics of deteriorating seeds include changes in color, morphology, biochemistry, genetics, and physiology. Key factors influencing the rate of deterioration are temperature, moisture content, fluctuating conditions, oxygen levels, microbes, and insects. Common methods to test for deterioration are germination testing, tetrazolium testing, and analyzing
This document summarizes the different classes of seeds in the development and certification process. It begins with nucleus seed, which is genetically pure seed from a small number of selected plants. Breeder's seed is produced from nucleus seed and is used to produce foundation seed. Foundation seed is multiplied to produce registered seed, which can be further multiplied to produce certified seed, the class that is sold to farmers. Certified seed must meet standards for genetic purity, identity and quality.
Seed production involves multiplying superior seed varieties while maintaining genetic purity and high quality standards. Key aspects of seed production include defining classes of seeds from nucleus to certified seeds; ensuring seeds meet testing standards for germination, purity and health; and involving various national and international organizations to facilitate quality seed availability and trade. Seed technology aims to harness a seed's genetic potential through scientific production, processing, and distribution methods.
The document outlines seed certification procedures, which ensure quality seeds for farmers. Seed certification verifies genetic identity and purity, germination rates, and freedom from diseases. It involves registering seed producers, inspecting seed fields for standards, processing and testing seeds, and issuing certificates for certified seeds. The goal is to provide high-quality seeds of improved varieties to increase crop production.
Seed is a very important part of a plant and preventing them from spoilage is an important operation for continuing the crop production and maintaining the Biodiversity.
1) Between 25-50% of grain is lost post-harvest in developing countries, with 10.7% lost during storage alone.
2) Proper seed storage requires maintaining cool, dry conditions to reduce seed metabolic activity and prolong viability. Orthodox seeds like rice can be dried and stored long-term at 5% moisture, while recalcitrant seeds like mango cannot be dried.
3) Key factors for successful storage are seed type, quality, moisture content below 13% for rice, and controlled environment below 30°C and 60% relative humidity to prevent pest and microbe growth.
This document discusses seed viability, dormancy, and storage. It defines seed viability as the ability of a seed to germinate and produce a normal seedling. Seed viability can be reduced by adverse weather during development or environmental conditions after maturity. Methods to test viability include tetrazolium tests, germination tests, and x-ray analysis. Seed dormancy is when viable seeds do not germinate under favorable conditions. Causes of dormancy include impermeable seed coats and immature embryos. Dormancy can be broken through mechanical or chemical scarification. Seed storage aims to maintain seed quality until planting by keeping seeds dry and cool in sealed containers or conditioned facilities.
Seed dormancy allows seeds to remain dormant during unfavorable conditions until conditions become suitable for germination. There are two main types of dormancy - primary and secondary. Primary dormancy occurs due to internal factors like hormones, while secondary dormancy is caused by external factors like temperature. Dormancy can be overcome through methods like scarification, stratification, hormone treatment, and photoperiod manipulation. Seed dormancy provides important biological benefits like survival during drought or frost and dispersal to new areas.
Seed Moisture Content, Germination and Seed DormancyDhaval Bhanderi
This document discusses seed moisture content, germination, and dormancy. It defines key terms like equilibrium moisture content and explains how to determine moisture content using the oven drying method. It describes how to conduct a germination test, including the different substrates, environmental requirements, and how to evaluate seedlings. It also outlines the different categories of seedlings and types of seed dormancy. The document provides information on important seed testing concepts and procedures.
This document discusses seed processing and storage. The objectives of seed processing are to improve quality by removing impurities, maintaining viability and vigor, making handling easier, and increasing value. Methods used for processing include drying, cleaning, grading, packaging, labeling, and treatment. Storage aims to preserve seeds under controlled conditions to prolong viability for long periods. Factors that affect seed longevity are seed type, quality, coat integrity, moisture content, and storage environment. Orthodox seeds can be stored long-term at low temperature and humidity while recalcitrant seeds require different storage methods.
Seed processing is a vital part of ensuring high quality seed for end users. It includes cleaning, drying, treatment, packaging, and storage. The goals of seed processing are to reduce bulk, increase longevity by drying to a safe moisture level and treating with protectants, reduce variability in vigor, and improve uniformity in size and shape. The sequence of operations typically includes drying, receiving, pre-cleaning, conditioning, cleaning, separating, treating, weighing, bagging, and storage or shipping. Processing aims to separate inert materials and weed seeds from the seed lot while upgrading quality by eliminating damaged or low vigor seeds to obtain a high percentage of pure seed with maximum germination potential.
This document discusses seed germination. It begins by describing seed maturation and dormancy, where seeds undergo dehydration and metabolic changes to enter a dormant state. It then discusses the structures that maintain dormancy like the seed coat and chemical inhibitors. Germination occurs when dormancy is broken through changes in the seed's physical state and environment. The key stages of germination are imbibition, respiration, and mobilization of food reserves through enzymatic breakdown to provide nutrients and energy for embryonic growth. Germination ends with the rupture of the seed coat and emergence of the seedling.
This document provides an overview of seed germination in pulses. It discusses the key requirements for germination including water, oxygen, carbon dioxide, temperature, and light. It describes the two main types of seed germination - epigeal and hypogeal. The document also outlines the main physiological and biochemical changes that occur during seed germination, including imbibition, respiration, enzyme activation, storage compound breakdown, and seedling emergence. Finally, it summarizes several studies that evaluated changes in enzyme activity and biochemical components in specific pulse crops like mung bean, cowpea, and chickpea during germination.
Introduction to seed and seed technologyNSStudents
The Presentation is prepared by the N.S Institution of science, Markapur.
It consists of a basic introduction related to Introduction to seed and seed technology.
Seed quality is determined by physical, physiological, genetic, and storability characteristics. Maintaining genetic purity during seed production requires controlling the seed source, isolation distances, rouging fields, certification, and grow-out tests. Key steps in quality seed production include selecting suitable regions and seed plots, proper land preparation, recommended varieties, treatments, planting methods, weed/pest control, irrigation, and timely harvesting and drying. This ensures high-quality seeds that perform well and retain desirable traits.
General principles of seed production Junaid Abbas
The document discusses the importance of producing high quality pedigree seed through maintaining genetic purity and varietal characteristics. It states that seed production requires strict attention, high technical skills, and financial investment. Several factors can lead to the deterioration of seed varieties during production cycles, such as developmental variations due to different environmental conditions, mechanical mixtures during sowing and harvesting, natural crossing through pollination, and mutations. The document provides guidelines for maintaining varietal purity through practices like inspection of seed fields, rouging of off-type plants, adequate isolation distances, and periodic testing to ensure genetic purity is preserved in seed production.
Seed vigour is determined by the properties that allow seeds to germinate and grow in different environments. It is affected by both internal factors, like genotype and seed size, and external factors such as mechanical injury during harvesting, pre-harvesting conditions, soil temperature and moisture, tillage and fertilizer use, and moisture uptake. Smaller seeds tend to be less vigorous than medium or large seeds. Harvesting seeds before maturity and mechanical damage during harvesting can reduce seed vigour by allowing pathogens to enter seeds. High soil moisture and temperature during seed development and storage can increase respiration and pathogen growth, shortening storage life. Tillage and adequate fertilizer promote seed yield and vigour.
This document discusses best practices for maintaining genetic purity and quality in seed production. It identifies seven main causes of variety deterioration: developmental variation, mechanical mixture, mutation, natural crossing, minor genetic variation, influence of diseases, and issues from plant breeding techniques. Key recommendations include growing seeds in adapted regions, rogueing fields to remove off-type plants, providing adequate isolation between varieties, and certifying seeds according to generation to limit deterioration to four generations. Proper agronomic practices like seed treatment, isolation, and weed control are also important to maintain high quality seeds.
The document discusses various tests used to assess seed viability and vigor, including warm germination tests, tetrazolium tests, growth tests, and stress tests. The warm germination test is the standard test to assess viability by germinating seeds in ideal conditions. Tetrazolium tests use chemicals to determine potential germination. Growth tests measure speed and size of seedling growth. Stress tests like cold tests and accelerated aging expose seeds to stressful conditions to evaluate vigor. Proper testing helps farmers make management decisions about seeding rates and avoiding weeds.
This document discusses seed deterioration, including its definition, types, characteristics, factors, and methods for testing. Seed deterioration is defined as the irreversible loss of seed quality, viability, and vigor over time due to environmental factors. There are three main types of deterioration: field weathering during seed maturation, harvest and post-harvest deterioration from mechanical damage, and storage deterioration from high temperature and moisture levels. Characteristics of deteriorating seeds include changes in color, morphology, biochemistry, genetics, and physiology. Key factors influencing the rate of deterioration are temperature, moisture content, fluctuating conditions, oxygen levels, microbes, and insects. Common methods to test for deterioration are germination testing, tetrazolium testing, and analyzing
This document summarizes the different classes of seeds in the development and certification process. It begins with nucleus seed, which is genetically pure seed from a small number of selected plants. Breeder's seed is produced from nucleus seed and is used to produce foundation seed. Foundation seed is multiplied to produce registered seed, which can be further multiplied to produce certified seed, the class that is sold to farmers. Certified seed must meet standards for genetic purity, identity and quality.
Seed production involves multiplying superior seed varieties while maintaining genetic purity and high quality standards. Key aspects of seed production include defining classes of seeds from nucleus to certified seeds; ensuring seeds meet testing standards for germination, purity and health; and involving various national and international organizations to facilitate quality seed availability and trade. Seed technology aims to harness a seed's genetic potential through scientific production, processing, and distribution methods.
The document outlines seed certification procedures, which ensure quality seeds for farmers. Seed certification verifies genetic identity and purity, germination rates, and freedom from diseases. It involves registering seed producers, inspecting seed fields for standards, processing and testing seeds, and issuing certificates for certified seeds. The goal is to provide high-quality seeds of improved varieties to increase crop production.
Seed is a very important part of a plant and preventing them from spoilage is an important operation for continuing the crop production and maintaining the Biodiversity.
1) Between 25-50% of grain is lost post-harvest in developing countries, with 10.7% lost during storage alone.
2) Proper seed storage requires maintaining cool, dry conditions to reduce seed metabolic activity and prolong viability. Orthodox seeds like rice can be dried and stored long-term at 5% moisture, while recalcitrant seeds like mango cannot be dried.
3) Key factors for successful storage are seed type, quality, moisture content below 13% for rice, and controlled environment below 30°C and 60% relative humidity to prevent pest and microbe growth.
This document discusses seed viability, dormancy, and storage. It defines seed viability as the ability of a seed to germinate and produce a normal seedling. Seed viability can be reduced by adverse weather during development or environmental conditions after maturity. Methods to test viability include tetrazolium tests, germination tests, and x-ray analysis. Seed dormancy is when viable seeds do not germinate under favorable conditions. Causes of dormancy include impermeable seed coats and immature embryos. Dormancy can be broken through mechanical or chemical scarification. Seed storage aims to maintain seed quality until planting by keeping seeds dry and cool in sealed containers or conditioned facilities.
Seed dormancy allows seeds to remain dormant during unfavorable conditions until conditions become suitable for germination. There are two main types of dormancy - primary and secondary. Primary dormancy occurs due to internal factors like hormones, while secondary dormancy is caused by external factors like temperature. Dormancy can be overcome through methods like scarification, stratification, hormone treatment, and photoperiod manipulation. Seed dormancy provides important biological benefits like survival during drought or frost and dispersal to new areas.
Seed Moisture Content, Germination and Seed DormancyDhaval Bhanderi
This document discusses seed moisture content, germination, and dormancy. It defines key terms like equilibrium moisture content and explains how to determine moisture content using the oven drying method. It describes how to conduct a germination test, including the different substrates, environmental requirements, and how to evaluate seedlings. It also outlines the different categories of seedlings and types of seed dormancy. The document provides information on important seed testing concepts and procedures.
This document discusses seed processing and storage. The objectives of seed processing are to improve quality by removing impurities, maintaining viability and vigor, making handling easier, and increasing value. Methods used for processing include drying, cleaning, grading, packaging, labeling, and treatment. Storage aims to preserve seeds under controlled conditions to prolong viability for long periods. Factors that affect seed longevity are seed type, quality, coat integrity, moisture content, and storage environment. Orthodox seeds can be stored long-term at low temperature and humidity while recalcitrant seeds require different storage methods.
Seed processing is a vital part of ensuring high quality seed for end users. It includes cleaning, drying, treatment, packaging, and storage. The goals of seed processing are to reduce bulk, increase longevity by drying to a safe moisture level and treating with protectants, reduce variability in vigor, and improve uniformity in size and shape. The sequence of operations typically includes drying, receiving, pre-cleaning, conditioning, cleaning, separating, treating, weighing, bagging, and storage or shipping. Processing aims to separate inert materials and weed seeds from the seed lot while upgrading quality by eliminating damaged or low vigor seeds to obtain a high percentage of pure seed with maximum germination potential.
This document discusses seed germination. It begins by describing seed maturation and dormancy, where seeds undergo dehydration and metabolic changes to enter a dormant state. It then discusses the structures that maintain dormancy like the seed coat and chemical inhibitors. Germination occurs when dormancy is broken through changes in the seed's physical state and environment. The key stages of germination are imbibition, respiration, and mobilization of food reserves through enzymatic breakdown to provide nutrients and energy for embryonic growth. Germination ends with the rupture of the seed coat and emergence of the seedling.
This document provides an overview of seed germination in pulses. It discusses the key requirements for germination including water, oxygen, carbon dioxide, temperature, and light. It describes the two main types of seed germination - epigeal and hypogeal. The document also outlines the main physiological and biochemical changes that occur during seed germination, including imbibition, respiration, enzyme activation, storage compound breakdown, and seedling emergence. Finally, it summarizes several studies that evaluated changes in enzyme activity and biochemical components in specific pulse crops like mung bean, cowpea, and chickpea during germination.
Seed dormancy is fully explained in this ppt. it includes causes ( dormancy due to hard seed coat, dormancy due to condition of embryo, dormancy due to absence of light, dormancy due to low temperature etc. ) of seed dormancy, types of seed dormancy, various methods to remove seed dormancy like impaction, stratification, scarification, exposure of seed to light
The document discusses seed germination and dormancy. It describes the process of seed germination, which begins with water uptake and involves a series of cellular and metabolic events that activate respiration and transport nutrients from storage tissues to the growing embryo. Completion of germination can be blocked by dormancy, which is released by interactions between plant growth hormones. Knowledge of a crop's mode of reproduction is important for developing effective breeding and selection methods suited to its natural reproductive processes.
Seed germination, growth factor and seed dormancy presented by Ankit Boss Go...AnkitBossGoldenHeart
This document summarizes a presentation on plant biochemistry focusing on seed dormancy. It defines seed dormancy as when seeds are prevented from germinating under normal conditions. It discusses the different types of seed dormancy including seed-coat induced, embryo-induced, and secondary dormancy. The causes of seed dormancy include hard seed coats, underdeveloped or dormant embryos, and the presence of germination inhibitors. Methods for breaking dormancy include scarification, stratification, and the use of alternating temperatures, light, and growth regulators. Seed dormancy provides advantages like helping plants survive cold temperatures and ensuring survival in tropical regions. Factors that affect germination include water, temperature, atmospheric conditions, soil properties, and seed
Morphogenesis, organogenesis, embryogenesis & other techniquesHORTIPEDIA INDIA
The document describes the process of somatic embryogenesis. It involves 7 key steps:
1) Induction of embryogenesis from explant tissue on media supplemented with auxin
2) Development of somatic embryos through globular, heart, and torpedo stages of growth
3) Maturation of embryos with the formation of root and shoot meristems and cotyledons
4) Conversion of mature embryos to plantlets through germination on auxin-free media
Factors like explant type, growth regulators, and genotype influence the process. Somatic embryos differ from zygotic embryos in lacking a seed coat and having greater potential for propagation but weaker plantlets.
This document provides an overview of plant embryology and seed dormancy. It begins with definitions of embryology and the structures studied, including the flower, stamen, anther, and ovule. It describes processes like microsporogenesis, megasporogenesis, double fertilization, and the development of the dicot and monocot embryos. It also discusses seed dormancy types, causes, methods of breaking dormancy both natural and artificial, and the importance of seed dormancy.
This ppt includes the following-
1.What is Seed Germination
2.Pattern Of Seed Germination
3.Physiology Of Seed Germination
4.Various Roles of GA in Seed Germination
Seed germination begins with water uptake and involves three key physiological processes:
1) Respiration increases rapidly to provide energy for biochemical changes through the mobilization of sucrose reserves.
2) Mobilization of stored proteins, lipids, and starches provides building blocks and energy for embryonic development.
3) Water uptake occurs in three phases - an initial rapid uptake, followed by a lag phase, then a second phase of rapid uptake as the radicle emerges and oxygen becomes more available. These processes support the growth of the embryonic axis from the seed.
PHYSIOLOGY AND BIOCHEMISTRY OF SEED GERMINATION.pptxpavanknaik
Seed germination begins with water uptake by the dry seed and ends with the emergence of the embryonic axis, usually the radicle, from the seed coat. During germination, seeds undergo physiological and biochemical changes. Water uptake leads to respiration and the mobilization of stored food reserves to provide energy and materials for embryonic development. Stored carbohydrates, lipids, proteins, and inorganic nutrients are broken down into simpler molecules that are used to fuel growth or transported to the growing embryo. Once the radicle has elongated enough to emerge from the seed coat layers, germination is complete.
This document discusses seed dormancy, including its types, mechanisms, classification, and measures to overcome it. It covers:
- The importance of seed dormancy in allowing time-delayed germination for survival.
- Primary classifications of dormancy include innate, enforced, and induced dormancy. Additional classifications include dormancy originating from inside or outside the embryo.
- Mechanisms include inhibitors within the embryo or seed coat interfering with germination.
- Treatments like chilling, scarification, light, and chemicals can help overcome dormancy.
- Dormancy also occurs in buds, tubers, and whole plants, regulated by hormones like ABA, GA, ethylene, and cytokinin.
Plant tissue culture involves growing plant cells, tissues or organs in sterile conditions on nutrient media. Some key points:
- Callus culture involves growing an unorganized cell mass (callus) from explants on auxin-cytokinin media, which can then be used for micropropagation.
- Cell suspension culture breaks up callus into single cells that grow in liquid media, allowing for easier scaling up than callus.
- Micropropagation is the process of rapidly multiplying plant materials like shoots, roots or embryos in culture to produce many clonal copies of plant materials like orchids or strawberries.
- Protoplast isolation and culture allows the transfer of genes directly into plant cells without the
Seeds require specific environmental conditions to germinate successfully, including appropriate levels of light, moisture, temperature, and oxygen. Germination occurs in three stages - imbibition, lag phase, and emergence phase. Seed dormancy refers to viable seeds that are unable to germinate due to external conditions or internal factors. Methods to overcome dormancy include scarification, soaking, and stratification. French beans exhibit epigeal germination while broad beans exhibit hypogeal germination. Seed viability refers to the ability to germinate, and storage affects both viability and germination potential over time depending on storage conditions and species.
This document provides information about a seminar on micropropagation techniques in fruit crops. It discusses the need for micropropagation due to issues like seasonal limitations and virus transmission. The advantages of micropropagation include producing true-to-type plants, overcoming seasonal constraints, and allowing large-scale multiplication. The document outlines the stages of micropropagation including establishment, proliferation, rooting, and acclimatization. It also describes different approaches like axillary budding and somatic embryogenesis. Several case studies demonstrate the use of micropropagation in plants like date palm, mango, and lemon.
Plant dormancy is a survival mechanism where growth is temporarily suspended. There are two main types - seed dormancy and bud dormancy. Seed dormancy prevents germination during unsuitable conditions and allows for dispersal. It can be caused by hard seed coats or environmental factors. Bud dormancy suspends growth in perennial plants during winter. Hormones like ABA promote dormancy while gibberellins and cytokinins break dormancy. Temperature also influences seed germination and dormancy breaking. Dormancy ensures plant survival during unfavorable periods and promotes species survival.
Embryo culture involves growing immature or mature embryos in vitro with the goal of producing a viable plant. There are two main types - mature embryo culture, which cultures embryos from ripe seeds, and immature embryo culture, also called embryo rescue, which cultures immature embryos to produce plants from wide crosses. The document then discusses the media requirements and factors that influence embryo culture, including minerals, carbohydrates, amino acids, plant extracts, and growth regulators. Applications of embryo culture in maize and other plants include producing haploids, preventing embryo abortion from wide crosses, overcoming seed dormancy, shortening breeding cycles, and preventing abortion in early fruit crops.
Dormancy, germination, and seed developmentAYAK SILAS
Seed development begins with fertilization and involves the growth of the embryo and endosperm within the ovule. As development progresses, the ovule expands and its tissues differentiate into protective seed coat layers. The embryo develops organs and is nourished by the endosperm. Seed germination occurs when environmental conditions allow the embryo to resume growth, rupturing the seed coat and developing a root and shoot. Key factors influencing germination include temperature, moisture, soil minerals, and light. Germination can be epigeal, where the hypocotyl and cotyledons emerge above ground, or hypogeal, where only the hypocotyl emerges while the cotyledons remain below ground.
This document discusses plant growth and development, including seed germination, the role of growth regulators (auxins, gibberellins, cytokinins, ethylene, and abscisic acid), and photoperiodism. It defines growth and outlines the phases and factors that influence growth. It describes seed dormancy and the changes that occur during seed germination. The roles and characteristics of the main plant growth hormones are summarized. The document also categorizes plants based on their responses to photoperiodism and defines vernalization.
Embryo culture and it's significance, introduction about embryo culture, types of embryo culture, mature embryo culture, immature embryo culture, procedure of embryo culture, technique of embryo culture, significance of embryo culture, application for embryo culture.
This document discusses seed dormancy, which prevents seeds from germinating under unsuitable conditions. It defines seed dormancy and describes its merits of preventing pre-harvest sprouting and allowing seeds to survive adverse conditions. The document also classifies seed dormancy and discusses mechanisms like seed coat impermeability and hormone levels. Methods for breaking dormancy include scarification, stratification, temperature treatments, washing, and chemical treatments.
Seed sampling, seed lot, types of samples, principles and procedures of seed sampling, sampling intensity, types of sampling devices, types of seed divider
seed moisture content, different methods of moisture testing, moisture content standards of agricultural crops according to Indian Minimum Seed Certification Standard
The Svalbard Global Seed Vault is located in a remote Arctic island of Spitsbergen in Norway. It serves as a backup storage facility for seeds from genebanks around the world. The seeds are preserved in the permafrost and used as a safeguard against loss from natural disasters or political conflicts. It ensures global food security by providing duplicate samples of seeds that can be used to rebuild crop diversity if major collections are destroyed.
1. The document discusses the purpose, principles, types, and stages of seed storage. The main purposes of seed storage are to preserve planting stocks from one season to the next and to maintain seeds in good physical and physiological condition from harvest until planting.
2. Seed storage is broadly classified into four types: storage of commercial seeds, carryover seeds, foundation/stock seeds, and germplasm seeds. Seed storage also progresses through several stages from maturity on the plant until germination.
3. Key principles of seed storage include maintaining low moisture content and cool temperatures, pest control, sanitation, drying seeds before storage, and storing only high quality seed suited to the storage period and system.
This document discusses the classification of seeds based on their storage behavior. It begins by defining seed storage, deterioration, life span, and longevity. It then summarizes Ewart's 1908 classification of seeds into three categories (microbiotic, mesobiotic, macrobiotic) based on lifespan under optimal storage conditions. However, this classification is too rigid.
The document goes on to describe the two major classes recognized today - orthodox and recalcitrant seeds. Orthodox seeds can be dried and stored at low temperatures, while recalcitrant seeds cannot survive drying or freezing. An intermediate category is also discussed. Various plant examples are provided for each classification. Factors that can help predict a seed's storage behavior are outlined.
Evidence of Jet Activity from the Secondary Black Hole in the OJ 287 Binary S...Sérgio Sacani
Wereport the study of a huge optical intraday flare on 2021 November 12 at 2 a.m. UT in the blazar OJ287. In the binary black hole model, it is associated with an impact of the secondary black hole on the accretion disk of the primary. Our multifrequency observing campaign was set up to search for such a signature of the impact based on a prediction made 8 yr earlier. The first I-band results of the flare have already been reported by Kishore et al. (2024). Here we combine these data with our monitoring in the R-band. There is a big change in the R–I spectral index by 1.0 ±0.1 between the normal background and the flare, suggesting a new component of radiation. The polarization variation during the rise of the flare suggests the same. The limits on the source size place it most reasonably in the jet of the secondary BH. We then ask why we have not seen this phenomenon before. We show that OJ287 was never before observed with sufficient sensitivity on the night when the flare should have happened according to the binary model. We also study the probability that this flare is just an oversized example of intraday variability using the Krakow data set of intense monitoring between 2015 and 2023. We find that the occurrence of a flare of this size and rapidity is unlikely. In machine-readable Tables 1 and 2, we give the full orbit-linked historical light curve of OJ287 as well as the dense monitoring sample of Krakow.
Immersive Learning That Works: Research Grounding and Paths ForwardLeonel Morgado
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
PPT on Direct Seeded Rice presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
JAMES WEBB STUDY THE MASSIVE BLACK HOLE SEEDSSérgio Sacani
The pathway(s) to seeding the massive black holes (MBHs) that exist at the heart of galaxies in the present and distant Universe remains an unsolved problem. Here we categorise, describe and quantitatively discuss the formation pathways of both light and heavy seeds. We emphasise that the most recent computational models suggest that rather than a bimodal-like mass spectrum between light and heavy seeds with light at one end and heavy at the other that instead a continuum exists. Light seeds being more ubiquitous and the heavier seeds becoming less and less abundant due the rarer environmental conditions required for their formation. We therefore examine the different mechanisms that give rise to different seed mass spectrums. We show how and why the mechanisms that produce the heaviest seeds are also among the rarest events in the Universe and are hence extremely unlikely to be the seeds for the vast majority of the MBH population. We quantify, within the limits of the current large uncertainties in the seeding processes, the expected number densities of the seed mass spectrum. We argue that light seeds must be at least 103 to 105 times more numerous than heavy seeds to explain the MBH population as a whole. Based on our current understanding of the seed population this makes heavy seeds (Mseed > 103 M⊙) a significantly more likely pathway given that heavy seeds have an abundance pattern than is close to and likely in excess of 10−4 compared to light seeds. Finally, we examine the current state-of-the-art in numerical calculations and recent observations and plot a path forward for near-future advances in both domains.
(June 12, 2024) Webinar: Development of PET theranostics targeting the molecu...Scintica Instrumentation
Targeting Hsp90 and its pathogen Orthologs with Tethered Inhibitors as a Diagnostic and Therapeutic Strategy for cancer and infectious diseases with Dr. Timothy Haystead.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Anti-Universe And Emergent Gravity and the Dark UniverseSérgio Sacani
Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law for entanglement entropy. The extension to de Sitter space requires taking into account the entropy and temperature associated with the cosmological horizon. Using insights from string theory, black hole physics and quantum information theory we argue that the positive dark energy leads to a thermal volume law contribution to the entropy that overtakes the area law precisely at the cosmological horizon. Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter. The emergent laws of gravity contain an additional ‘dark’ gravitational force describing the ‘elastic’ response due to the entropy displacement. We derive an estimate of the strength of this extra force in terms of the baryonic mass, Newton’s constant and the Hubble acceleration scale a0 = cH0, and provide evidence for the fact that this additional ‘dark gravity force’ explains the observed phenomena in galaxies and clusters currently attributed to dark matter.
Mending Clothing to Support Sustainable Fashion_CIMaR 2024.pdfSelcen Ozturkcan
Ozturkcan, S., Berndt, A., & Angelakis, A. (2024). Mending clothing to support sustainable fashion. Presented at the 31st Annual Conference by the Consortium for International Marketing Research (CIMaR), 10-13 Jun 2024, University of Gävle, Sweden.
Discovery of An Apparent Red, High-Velocity Type Ia Supernova at 𝐳 = 2.9 wi...Sérgio Sacani
We present the JWST discovery of SN 2023adsy, a transient object located in a host galaxy JADES-GS
+
53.13485
−
27.82088
with a host spectroscopic redshift of
2.903
±
0.007
. The transient was identified in deep James Webb Space Telescope (JWST)/NIRCam imaging from the JWST Advanced Deep Extragalactic Survey (JADES) program. Photometric and spectroscopic followup with NIRCam and NIRSpec, respectively, confirm the redshift and yield UV-NIR light-curve, NIR color, and spectroscopic information all consistent with a Type Ia classification. Despite its classification as a likely SN Ia, SN 2023adsy is both fairly red (
�
(
�
−
�
)
∼
0.9
) despite a host galaxy with low-extinction and has a high Ca II velocity (
19
,
000
±
2
,
000
km/s) compared to the general population of SNe Ia. While these characteristics are consistent with some Ca-rich SNe Ia, particularly SN 2016hnk, SN 2023adsy is intrinsically brighter than the low-
�
Ca-rich population. Although such an object is too red for any low-
�
cosmological sample, we apply a fiducial standardization approach to SN 2023adsy and find that the SN 2023adsy luminosity distance measurement is in excellent agreement (
≲
1
�
) with
Λ
CDM. Therefore unlike low-
�
Ca-rich SNe Ia, SN 2023adsy is standardizable and gives no indication that SN Ia standardized luminosities change significantly with redshift. A larger sample of distant SNe Ia is required to determine if SN Ia population characteristics at high-
�
truly diverge from their low-
�
counterparts, and to confirm that standardized luminosities nevertheless remain constant with redshift.
2. Structure of Monocot Seed
Seed coat : Provides protection
Endosperm/Cotyledon : Store food
Aleurone cells : Store abundant proteins and enzymes
Prof. Kumari Rajani, DSST, BAU, Sabour
3. The triploid endosperm is composed of two tissues:
Starchy endosperm
Aleurone layer
The nonliving starchy endosperm consists of thin walled cells filled
with starch grains and it is centrally located
Living cells of the aleurone layer, which surrounds the endosperm,
synthesize and release hydrolytic enzymes into the endosperm during
germination
As a consequence, the stored food reserves of the endosperm are
broken down, and the solubilized sugars, amino acids, and other products
are transported to the growing embryo via the scutellum
The isolated aleurone layer, consisting of a homogeneous population of
cells responsive to gibberellin, has been widely used to study the
gibberellin signal transduction pathway in the absence of non responding
cell types Prof. Kumari Rajani, DSST, BAU, Sabour
4. Structure of Dicot Seed
Radicle Root
Plumule Shoot and leaves
Prof. Kumari Rajani, DSST, BAU, Sabour
5. Seed Germination
“Germination begins with water uptake by the seed (imbibition) and
ends with the start of elongation by the embryonic axis, usually the
radicle”
Field or Greenhouse condition
“a seedling emerges from the soil”
SeedTesting
“development of a normal seedling”
Physiologist
“the emergence of radicle from a seed”
Prof. Kumari Rajani, DSST, BAU, Sabour
6. Cotyledon
(provide food to the
growing embryo)
Epicotyl
(above the cotyledon)
Hypocotyl
(below the cotyledon)
Basis for the
plant’s stem
Leaves
Prof. Kumari Rajani, DSST, BAU, Sabour
When the radicle has grown out of the covering seed layers,
the process of seed germination is completed
7. Germination does not include seedling growth after
radicle emergence, which is referred to as Seedling
establishment or Field establishment
Similarly, the rapid mobilization of stored food reserves
that fuels the initial growth of the seedling is considered a
Post germination process
Prof. Kumari Rajani, DSST, BAU, Sabour
8. Hypogeal germination of pea seed
Epigeal germination of bean seed
Types of Seed Germination
Epigeal Germination
Cotyledons are raised out of the soil
Epigeal germination takes place by the
rapid extension of hypocotyle before
the growth of the epicotyle
Evolutionary more primitive than
hypogeal
Ex: Bean, Castor, Mustard, Tamarind,
Sunflower, Onion, Papaya, Pine etc
Hypogeal Germination
Cotyledons remains underground
Hypogeal germination takes place by
the rapid extension of epicotyle and
the growth of hypocotyle is restricted
Ex: Paddy, Wheat, Maize, Gram, Pea,
Mango, Groundnut etc
Prof. Kumari Rajani, DSST, BAU, Sabour
9. Radicle emergence: in most of species
Hypocotyle emergence: Bromeliaceae, Chenopodiaceae,
Onagracea, Palmae, Saxifragaceae and Typhaceae
Coleoptile emergence: Maize, Oropetium tomaeum
Elongation of the mesocotyle elevates the coloeoptile and its
enclosed inner leaves towards the soil surface
The mesocotyl is the tubular, white, stemlike tissue
connecting the seed and the base of the coleoptile
The mesocotyl
is the first
internode of
the stem
Prof. Kumari Rajani, DSST, BAU, Sabour
10. The entire process of germination (water uptake by a
germinating seed) may be divided into three broad phases;
it shows triphasic pattern
• Phase I: Imbibition phase
• Phase II: Active metabolism or Plateau or Lag phase
• Phase III: Cell expansion & radicle protrusion & further
increase in water uptake
Phases of Germination
The most critical phase is phase II whereas, the
physiological and biochemical processes such as
hydrolysis, macromolecules biosynthesis, respiration,
subcellular structures, and cell elongation are reactivated
resulting in initiation of germination
Prof. Kumari Rajani, DSST, BAU, Sabour
11. Phase I : Imbibition phase
The initial rapid uptake of water by the dry seed during Phase I
is referred to as Imbibition
It is the first key event that moves the seed from a dry, dormant
organism to the resumption of embryo growth
The extent to which water imbibition occurs is dependent on three
factors:
composition of the seed
seed coat permeability
water potential
Species produce seeds with impermeable testa called hard seeds
(hardseededness)
Ex: Leguminosae, Cannaceae, Chenopodiaceae, Convolvulaceae and
Malvaceae Prof. Kumari Rajani, DSST, BAU, Sabour
12. Imbibition Phase is relatively shorten and characterized by rapid water
uptake
Chief changes during imbibition phase:
• Absorption of water
• Absorption of other substances
• Release of gases
• Increase in volume of seeds due to swelling
• Leakage of solutes
The initial period of imbibition induces an immediate and rapid leakage of
solutes such as sugars, organic acids, amino acids, proteins, phenolics,
phosphate and ions, from the seed tissues but it rapidly decreases and
becomes negligible within about 30 min to 1 hr
The leakage results in loss of enzymes like glucose-6-phosphate
dehydrogenase, glutamate dehydrogenase, cytochrome oxidase and
fumarase
Prof. Kumari Rajani, DSST, BAU, Sabour
13. “The release of non-respiratory gases as a result of very rapid seed
imbibition”
• It is immediate and last only a few minutes
• It occurs by the release of adsorbed atmospheric gases (Oxygen,
Nitrogen, Carbon dioxide) retained in the dry porous structures
of the seed coats
Wetting Burst
Prof. Kumari Rajani, DSST, BAU, Sabour
14. Imbibitional chilling injury is defined as sensitivity to a
combination of low seed-water content and imbibition at
cold temperature
The severity of injury depends upon several factors such as
(i) The species or the cultivars involved
(ii) The initial water content of the seed
(iii) The temperature to which seed is exposed
(iv) The duration of chilling exposure
(v) The period during the course of germination when the chilling
exposure takes place
Ex: Cotton, Soybean, Limabean, Maize
Imbibitional Injury
Prof. Kumari Rajani, DSST, BAU, Sabour
15. Water uptake by imbibition declines and metabolic processes,
including transcription and translation, are reinitiated
The seed volume may increase as a result embryo expands and the
radicle emerges from the seed coat
The emergence of the radicle through the seed coat in Phase II
marks the end of the process of germination
Radicle emergence can be either a one-step process in which
the radicle emerges immediately after the seed coat (testa) is
ruptured, or it may involve two steps in which the endosperm must
first undergo weakening before the radicle can emerge
Phase II : Plateau or Lag phase
Prof. Kumari Rajani, DSST, BAU, Sabour
16. Dry seeds contain several enzymes, which are desiccation
tolerant and can become active only after sufficient hydration of
seeds
Major metabolic pathways affected respiration, protein synthesis,
DNA replication, RNA synthesis
Prof. Kumari Rajani, DSST, BAU, Sabour
17. Mobilization of Stored Reserves
The major food reserves of angiosperm seeds are typically stored in the
cotyledons or in the endosperm
The massive mobilization of reserves that occurs after germination provides
nutrients to the growing seedling until it becomes autotrophic
At the subcellular level, starch is stored in amyloplasts in the endosperm of
cereals
Two enzymes responsible for initiating starch degradation are α- and β-
amylase
α-Amylase hydrolyzes starch chains internally to produce oligosaccharides
consisting of α (1,4)-linked glucose residues
β-Amylase degrades these oligosaccharides from the ends to produce
maltose, a disaccharide. Maltase then converts maltose to glucose
Prof. Kumari Rajani, DSST, BAU, Sabour
18. Protein storage vacuoles are the primary source of amino acids
for new protein synthesis in the seedling
In addition, protein storage vacuoles contain phytin, the K+,
Mg2+, and Ca2+ salt of phytic acid a (myo-inositol hexaphosphate),
a major storage form of phosphate in seeds
During food mobilization, the enzyme phytase hydrolyzes phytin
to release phosphate and the other ions for use by the growing
seedling
Prof. Kumari Rajani, DSST, BAU, Sabour
19. During Phase III the rate of water uptake increases rapidly due to
the onset of cell wall loosening and cell expansion
Protrusion of radical during germination is caused by cell
expansion or elongation before cell division
Ex: Maize, Barley, Broad beans, Pea etc
Pinus lambertiana: cell division and cell elongation occur
simultaneuosly
Prunus cerasus: cell division precedes cell elongation
Phase III : Cell expansion & Radicle protrusion
Prof. Kumari Rajani, DSST, BAU, Sabour
23. Process: Seed Germination
1. Imbibition
- water uptake, softens
inner tissues
- causes swelling and
seed coat rupture
- more water uptake
2. Gibberelic Acid
- plant hormone
(similar to steroids)
- dissolved & distributed
by water
Prof. Kumari Rajani, DSST, BAU, Sabour
24. 2. Gibberelic Acid
- arrives at aleurone cells
- activates certain genes
3. Transcription
Transportation
Translation amylase
4. Amylase accelerates
hydrolysis of starch
Process: Seed Germination
Prof. Kumari Rajani, DSST, BAU, Sabour
25. Hydrated starch
moves to the
cotyledon and
radicle to initiate
growth
Process: Seed Germination
Prof. Kumari Rajani, DSST, BAU, Sabour
26. Factors affecting Germination
Internal Factors External Factors
Seed Vitality
Seed Age or Maturity
Seed Dormancy
Mechanical Damage
(The effect of mechanical
injury is greater when it
affect the embryo)
Water
Air
(Oxygen & Carbon dioxide)
Temperature
Light
Prof. Kumari Rajani, DSST, BAU, Sabour
27. Water
Water is clearly the most important factor in germination
An adequate continuous supply of water is necessary for assumption of the
physiology, metabolism and molecular processes that drive germination
Water functions as triggering enzyme for starch conversion into sugar, turgor
pressure for moving the radicle root down and the cotyledons up, and for
transporting nutrients and enzymes within the seed
Recalcitrant seeds usually do not require external water for germination since
their natural water content is sufficient for them to complete germination
Germination on parent tree before shedding: Spp. of Mangrove swamps such as
Rhizophoraceae, Rhizophora spp, Bruguiera gymmorrhiza, Cerops tagal, Avicennia
marina
In fleshy fruits within which they are enclosed: Mango
Prof. Kumari Rajani, DSST, BAU, Sabour
28. Excess of water is harmful and seeds don not germinate when immersed in
water
Sugarbeet seeds: A thin layer of water around the seed inhibits
germination
Barley: Germination is affected by excess water, which is called as water
sensitivity (Excess of water intervenes indirectly by depriving the embryo of
oxygen)
Typha latifolia (Aquatic plant) and Paddy: Germinate well when covered
with water (under reduced oxygen levels)
Cynodon dactylon: Germinate in low oxygen levels
Oldenlandia corymbosa (tropical weed): Germinate only when
completely immersed
Prof. Kumari Rajani, DSST, BAU, Sabour
29. Oxygen
Oxygen in presence of enough moisture causes respiration to start
metabolism and it creates energy for the germination process
Respiration rates for germinating seeds are very high; adequate
oxygen is necessary to complete respiration
Oxygen concentration higher than air: promotes germination
Carbon dioxide concentration higher than air: retards germination
Lettuce and Timothy grass (Phleum pratense)
If oxygen supply is limited during germination, emergence may not
occur due to inhibited growth
Prof. Kumari Rajani, DSST, BAU, Sabour
30. The germination percent of most seeds will be retarded if the
oxygen percent goes below 20 percent (Normal air is 20 percent
oxygen)
Typha latifolia (Aquatic plant) and Paddy: Germinate well
under reduced oxygen levels
Cynodon dactylon: Germinate in low oxygen levels
Oxygen removes metabolic waste from the cell; without oxygen,
waste is not removed and the cellular metabolism is slowed
Prof. Kumari Rajani, DSST, BAU, Sabour
31. • Light is another key germination factor; it can either stimulate or
inhibit seed germination
• Both light quality (light intensity) and quantity (duration of
exposure) influence seed germination
• Promotion of germination is generally through breaking the seed
dormancy
• Some crops have a requirement for light to assist seed germination
(e.g.Tobacco, Lettuce, Petunia, Begonias, Impatiens)
Light
Prof. Kumari Rajani, DSST, BAU, Sabour
32. Photoblastic: Seeds respond to light for germination
Three categories of photoblastic seeds:
(a) Positive photoblastic: Seeds that are stimulated to germinate
by light
Ex: Lettuce, Tobacco, Poa pratensis, Poa nemoralis,
mistletoe, Petroselinum crispum (Parsley) etc.
(a) Negative photoblastic: Seeds whose germination is inhibited
by light
Ex: Onion, Lily,Amaranthus, Nigella, etc.
(a) Non-photoblastic: Seed which germinates in light as well as
dark
Prof. Kumari Rajani, DSST, BAU, Sabour
33. Visible light radiation is required by seed for germination
Maximum promotion of
germination occurs at 660 to
670 nm with a peak at 670 nm
(red area) since phytochrome
has an absorption maximum
at this wavelength
Wavelengths >700 nm and
<290 nm: inhibit germination
Prof. Kumari Rajani, DSST, BAU, Sabour
34. Phytochrome is a plant pigment found in cytoplasm that senses
the presence of red light
Phytochrome absorbs light in two inter-convertible forms
1. Phytochrome-red (Pr) is metabolically inactive & absorbs red
light (660 nm)
2. Phytochrome-far red (Pfr) is metabolically active and gets
transformed from Pr
The Pfr promotes germination and other phytochrome-
controlled processes in plants
Pfr reverts back to Pr after absorbing far-red (730 nm)
Photoreversible Germination
Prof. Kumari Rajani, DSST, BAU, Sabour
35. This reversible effect of red to far-
red light was first reported in 1952
in lettuce and also shown by other
plant spp. like tobacco, pepper grass,
elm, birch etc
Inactive form Active form
The light intensity should be approx 750 to 1250 lux in seed
germinator for light requiring seeds and 250 lux is sufficient for
non-dormant seeds
Prof. Kumari Rajani, DSST, BAU, Sabour
36. This is determined by how the seed would naturally be sown
Small seeds must sprout on the surface of soil because they lack a
suitable endosperm to supply the needed nutrients; these are
typically aided by light exposure
Large seeds contain enough nutrition to grow underground when
photosynthesis is not possible. These seeds are more likely to
germinate in dark conditions
Prof. Kumari Rajani, DSST, BAU, Sabour
37. Temperature
A favorable temperature is necessary to allow for plant growth
Temperature not only affects the germination percentage but also the
rate of germination
For every species of seed, there is an optimal temperature for
germination; at that temperature, the maximum number of seeds will
germinate and in less time than at any other temperature
The optimum temperature for most seeds is between 15°C and
30°C
Kharif crops: 25°C and Rabi Crops: 20°C
The maximum temperature for most species is between 35°C and
40°C
Prof. Kumari Rajani, DSST, BAU, Sabour
38. At some point, the seed becomes sensitive to the presence of
“trigger” agents
A “trigger” agent can be defined as a factor that elicits
germination but whose continued presence is not required
throughout germination
A “trigger” agent such as light or temperature alterations shift
the balance of inhibitors to favor promoters such as gibberellins
In contrast, a “germination” agent is a factor that must be
present throughout the germination process; an example is
Gibberellic Acid
Trigger and Germination Agents
Prof. Kumari Rajani, DSST, BAU, Sabour
40. SeedTesting
“Seed Germination is the
emergence and development of
the seedling to a stage where the
aspect of its essential structures
indicates whether or not it is able
to develop further into a
satisfactory plant under favorable
conditions in the field”
(ISTA, 2015)
Seed Germination
Physiologist
“the emergence of radicle and
plumule”
Prof. Kumari Rajani, DSST, BAU, Sabour
41. Germination paper/sand
Wax or butter paper
Petri plate
Seed germination chamber
Plastic boxes or tray or pots
Rubber band
Seed counting board
Marking pencil/pen
Materials Required for Germination Testing
Prof. Kumari Rajani, DSST, BAU, Sabour
42. Composition: the growing medium can be paper, pure sand or
mixtures of organic compounds with added mineral particles
Characteristics of germination paper
It should be porous in nature
It should have maximum water holding capacity to ensure
continuous supply of water during the test period
Free from bacteria, dirt, fungi and toxic substances
Made out of 100% cellulose
pH should be 6-7.5
Paper should posses sufficient strength to the prevent penetration
of root in to the paper
Paper size is 46 X 29 cm
It should have reasonable cost
Should not serve as suitable media for saprophytic Fungi
Growing Media
Prof. Kumari Rajani, DSST, BAU, Sabour
43. a) Paper substrata
The paper substrata are used in the form of top of paper (TP) or
between paper (BP) tests
In most of the laboratories, paper-towel method (Roll towel test) is
most commonly used for medium sized and bold seeds
The paper substrata are not reusable
b) Sand substrata
The sand substrata have advantage of being relatively less
expensive and reusable
The results in sand media are more accurate and reproducible in
comparison with 'roll towel‘ tests especially in case of seed lots
that are aged or heavily treated with chemicals
Prof. Kumari Rajani, DSST, BAU, Sabour
44. Methods of seed germination using paper
A. Top of paper (TP): the
seeds are germinated on top
of one or more layers of
paper which are placed
B. Between paper (BP): the
seeds are germinated between
two layers of paper
C. Pleated paper (PP): the
seeds are placed in a pleated
paper strip with 50 pleats,
usually two to a pleat
Prof. Kumari Rajani, DSST, BAU, Sabour
45. i)Top of sand (TS), Top of organic growing medium (TO):
the seeds are pressed into the surface of the sand or the organic
growing medium.
ii) Sand (S), Organic growing medium (O): the seeds are
planted on a level layer of moist sand or the organic growing
medium and covered with 10–20 mm of uncompressed substrate,
depending on the size of the seed
Methods using sand or organic growing media
Prof. Kumari Rajani, DSST, BAU, Sabour
46. i) Top of paper covered with sand (TPS): the seeds are
germinated on top of a moistened sheet of cellulose paper
which is covered with a 2 cm layer of dry sand
ii) Soil: Soil is generally not recommended as a primary growing
medium
However, it may be used as an alternative to organic growing
media when seedlings show phytotoxic symptoms or if
evaluation of seedlings is in doubt on paper or sand
Methods using a combination of paper and sand
Prof. Kumari Rajani, DSST, BAU, Sabour
47. The accuracy and reproducibility of the germinator result
are very much dependent on the quality of the substrata
(paper and sand) used for germination testing
The germination substrata must meet the following basic
requirements:
It should be non-toxic to the germinating seedlings
It should be free from mould sand other microorganisms
It should provide adequate aeration and moisture to the
germinating seeds
It should be easy to handle and use
It should make good contrast for judging the seedlings
It should be less expensive
Prof. Kumari Rajani, DSST, BAU, Sabour
48. Important facts to be remembered…
pH: the growing medium must have a pH value within the range 6.0–7.5 when
checked in the substrate
Conductivity: the salinity must be as low as possible and no more than 40
millisiemens per metre
Measurements of conductivity can be replaced by biological tests
Cleanness and freedom from toxicity: the growing medium must be free
from seeds, fungi, bacteria or toxic substances, which may interfere with the
germination of seeds or the growth or evaluation of seedlings
Seed sample: 400 seeds are used for germination testing
Seedlings evaluation: is done on two days: (Different for various crops)
1. First Count 2. Second or Final Count
Prof. Kumari Rajani, DSST, BAU, Sabour
49. Re-use of substrates: it is strongly recommended that the
growing medium is only used once
Counting boards: Counting boards are often used for large seeds
such as Zea, Phaseolus and Pisum
Vacuum counters: Vacuum counters can in principle be used for
all species, but are mostly used for species with regularly shaped
and relatively smooth seeds such as cereals or species of Brassica
or Trifolium
Prof. Kumari Rajani, DSST, BAU, Sabour
51. Place 100 seeds on soaked paper
at equal distance in 8 rows
(12 seeds: 1, 3, 5, 7
13 seeds: 2, 4, 6, 8)
Place another soaked paper Roll in wax paper
Prof. Kumari Rajani, DSST, BAU, Sabour
52. Normal Seedlings: Seedlings that possess essential structures that is
indicative of their ability to produce useful mature plants under favorable field
conditions
Abnormal Seedlings: Seedlings that exhibit some form of growth but have
insufficient plant structures to maintain a healthy plant, such as missing roots
or shoots
Fresh Seeds: Seeds that have failed to germinate but have imbibed water.
They appear firm, fresh and capable of germination, but remain dormant
Dormant Seeds: Viable seeds (other than hard seeds) that fail to germinate
when given the prescribed or recommended germination conditions
Hard Seeds: Seeds that remains hard at the end of the prescribed test
period, because their seed coats are impermeable to water
Dead Seeds: Seeds that cannot produce any part of a seedling
Evaluation of germination test
Prof. Kumari Rajani, DSST, BAU, Sabour
53. Evaluation of seedlings
Normal Seedlings
Seedlings with all
essentials structures, well
developed, proportionate
root and shoot, healthy
AS
Prof. Kumari Rajani, DSST, BAU, Sabour
56. Replication
(100
seeds)
No. of
Normal
Seedlings
No. of
Abnormal
Seedlings
Ungerminated Seed
Germination
(%)
No. of Hard
Seeds
No. of Fresh
Seeds
No. of Dead
Seeds
R1 89 4 3 0 4 92 (89+3+0)
R2 92 2 1 2 3 95 (92+1+2)
R3 90 3 2 2 3 94 (90+2+2)
R4 87 3 5 0 5 92 (87+5+0)
Average % 89.5 3 2.75 1 3.75 93.25
Calculations and Reporting of Results
The results of the germination test are reported as percentage of normal seedlings,
abnormal seedling, hard seeds, fresh seeds and dead seeds
The sum of the normal, abnormal and ungerminated seeds must be 100 (90+3+3+1+3)
Germination percentage is calculated based on number of normal seedling
The percentage are rounded to the nearest whole number
Normal seedlings + Hard seeds + Fresh seeds
Germination (%) = X 100
Normal seedlings + Abnormal Seedlings + Hard + Fresh + Dead Seeds
Prof. Kumari Rajani, DSST, BAU, Sabour
57. Minimum Seed Certification Standard for Seed
Germination Percentage Recommended in Field Crops
Field Crops Foundation and Certified
Maize Hybrid (Sweet Corn Hybrid, Synthetic,
Composite, OPV)
90
Barley, Wheat, Triticale, Bengal gram, Rapeseed,
Mustard
85
Paddy, Maize (Inbred lines, Single cross FS),
Horse gram
80
Sorghum, Pearl millet, Minor millets, Black
gram, Cowpea, Green gram, Indian bean,
Lathyrus, Lentil, Moth Bean, Pea, Rajmash
75
Castor, Groundnut, 70
Prof. Kumari Rajani, DSST, BAU, Sabour