This document provides an overview of seed physiology, structure, function, and germination. It discusses that seeds serve to propagate plants, disperse offspring, and protect immature plants. Seeds contain an embryo (the baby plant), a seed coat (protective outer layer), and stored reserves (food for the germinating seedling). Germination requires water, oxygen, suitable temperature, stored food reserves, and dormancy to be broken. The sequence of germination includes imbibition, metabolic activity, and radicle emergence. Factors like depth, timing, and seedbed preparation influence successful germination and seedling establishment.
A detailed review on all the molecular mechanisms which promote and disrupt seed dormancy. Even genetic and epigenetic studies are also provided so as to have easy understanding
Embryo culture is a laboratory method for producing plant lets from a fertilized or unfertilized embryo in invitro condition. there are several advantages are associated with the embryo culture like production of haploid plants, making distant crosses successful, sometimes aborted embryos can be rescued from a unsuccessful hybridization.
The document describes the steps involved in micropropagation:
1. Explant selection from a donor plant
2. Establishment of the explant in culture media
3. Callus development and cell division from the explant
4. Development of plantlets from the callus tissue
5. Hardening or acclimatization of the plantlets for transplanting.
The document discusses seed dormancy in fruit and plantation crops. There are several types of seed dormancy including endogenous dormancy caused by internal seed factors and exogenous dormancy caused by external seed coat or fruit factors. Seed dormancy can be beneficial as it allows for storage, transport, and handling of seeds. The document outlines various causes of seed dormancy including a hard seed coat that prevents water or gas permeation, or poses a mechanical resistance. Dormancy can also be caused by an underdeveloped or fully developed embryo that is unable to resume growth.
This document discusses synthetic seeds, which are artificially encapsulated plant materials like somatic embryos, shoot buds, or cell aggregates that can be used for sowing like natural seeds. Synthetic seeds were originally only referred to somatic embryos for economic crop production, but now include other micropropagules. The first successful synthetic seed was produced in 1982 in carrot. There are two main types - desiccated synthetic seeds which are produced from desiccation tolerant species and hydrated synthetic seeds which encapsulate somatic embryos or shoots in hydrogels like sodium alginate. The encapsulation process involves a plant propagule, a gelling matrix that can include nutrients, and an artificial seed coat to develop the encapsulation system. Common encapsulation
history
Lampe & Mills (1933) were the first to report the proliferation of immature endosperm tissue of Maize, grown on medium containing extract of potato.
La Rue (1947) observed that in nature, in maize , the pericarp ruptured & the endosperm exhibited a white tissue mass.
Plant tissue culture involves growing plant cells, tissues or organs in sterile conditions on nutrient media. The key hormones auxin and cytokinin play important roles in differentiation. Tissue culture applications include micropropagation, germplasm preservation, haploid production, and genetic engineering. Important techniques include somatic embryogenesis, organogenesis, microcutting, anther/microspore culture, protoplast culture, and callus and cell suspension culture.
This document discusses the history and techniques of anther and pollen culture. It notes that anther and pollen culture were first developed in the 1950s and 1960s and can be used to produce haploid plants. The document outlines the procedures for anther and pollen culture, highlighting steps like collecting unopened flower buds, isolating microspores, and culturing on nutrient media. It also discusses factors that influence culture success like genotype, temperature, and physiological status of donor plants. The advantages of pollen culture over anther culture and various applications of anther and pollen culture are summarized.
A detailed review on all the molecular mechanisms which promote and disrupt seed dormancy. Even genetic and epigenetic studies are also provided so as to have easy understanding
Embryo culture is a laboratory method for producing plant lets from a fertilized or unfertilized embryo in invitro condition. there are several advantages are associated with the embryo culture like production of haploid plants, making distant crosses successful, sometimes aborted embryos can be rescued from a unsuccessful hybridization.
The document describes the steps involved in micropropagation:
1. Explant selection from a donor plant
2. Establishment of the explant in culture media
3. Callus development and cell division from the explant
4. Development of plantlets from the callus tissue
5. Hardening or acclimatization of the plantlets for transplanting.
The document discusses seed dormancy in fruit and plantation crops. There are several types of seed dormancy including endogenous dormancy caused by internal seed factors and exogenous dormancy caused by external seed coat or fruit factors. Seed dormancy can be beneficial as it allows for storage, transport, and handling of seeds. The document outlines various causes of seed dormancy including a hard seed coat that prevents water or gas permeation, or poses a mechanical resistance. Dormancy can also be caused by an underdeveloped or fully developed embryo that is unable to resume growth.
This document discusses synthetic seeds, which are artificially encapsulated plant materials like somatic embryos, shoot buds, or cell aggregates that can be used for sowing like natural seeds. Synthetic seeds were originally only referred to somatic embryos for economic crop production, but now include other micropropagules. The first successful synthetic seed was produced in 1982 in carrot. There are two main types - desiccated synthetic seeds which are produced from desiccation tolerant species and hydrated synthetic seeds which encapsulate somatic embryos or shoots in hydrogels like sodium alginate. The encapsulation process involves a plant propagule, a gelling matrix that can include nutrients, and an artificial seed coat to develop the encapsulation system. Common encapsulation
history
Lampe & Mills (1933) were the first to report the proliferation of immature endosperm tissue of Maize, grown on medium containing extract of potato.
La Rue (1947) observed that in nature, in maize , the pericarp ruptured & the endosperm exhibited a white tissue mass.
Plant tissue culture involves growing plant cells, tissues or organs in sterile conditions on nutrient media. The key hormones auxin and cytokinin play important roles in differentiation. Tissue culture applications include micropropagation, germplasm preservation, haploid production, and genetic engineering. Important techniques include somatic embryogenesis, organogenesis, microcutting, anther/microspore culture, protoplast culture, and callus and cell suspension culture.
This document discusses the history and techniques of anther and pollen culture. It notes that anther and pollen culture were first developed in the 1950s and 1960s and can be used to produce haploid plants. The document outlines the procedures for anther and pollen culture, highlighting steps like collecting unopened flower buds, isolating microspores, and culturing on nutrient media. It also discusses factors that influence culture success like genotype, temperature, and physiological status of donor plants. The advantages of pollen culture over anther culture and various applications of anther and pollen culture are summarized.
Artificial seeds are encapsulated somatic embryos that can convert into plants under in vitro and ex vitro conditions. Somatic embryos are bipolar structures that can form shoots and roots. There are two types of artificial seeds: desiccated and hydrated. Desiccated seeds are hardened and encapsulated while hydrated seeds remain hydrated using gels like calcium alginate. Artificial seeds allow for large scale propagation of plants, including non-seed producing plants and plants with problems in seed propagation. However, more research is still needed to optimize artificial seed technology for commercial use.
This document provides information about a lecture on the introduction to basic biotechnology and its importance, prospects, scope and limitations in horticulture. The key points covered are:
1) Biotechnology can help meet the increasing global demand for food through techniques like genetic engineering that allow for direct gene transfer and faster crop improvement compared to conventional breeding.
2) Genetic engineering is being used to develop horticultural crops with traits like pest and disease resistance, higher yields, improved quality and processing. However, it is not part of organic farming.
3) Techniques discussed that are useful in horticultural crop improvement include tissue culture, embryo culture, protoplast fusion, in vitro mutation, synthetic seeds,
Tissue culture involves the use of small pieces of plant tissue (explants) which are cultured in a nutrient medium under sterile conditions. Tissue culture is in vitro maintenance and propagation of isolated cells tissues or organs in an appropriate artificial environment.
This document discusses triploid production through endosperm culture and somatic embryogenesis. It defines endosperm culture as the in vitro development of isolated mature or immature endosperm tissue to obtain triploid plantlets. Two types of endosperm culture are described: mature and immature. The key steps and factors affecting endosperm culture are outlined. Somatic embryogenesis is defined as the development of embryos from somatic cells in vitro. The document compares somatic and zygotic embryos and describes the two routes of somatic embryogenesis: direct and indirect. The stages of somatic embryogenesis and factors influencing the process are summarized.
This document discusses in vitro plant breeding techniques. It describes how plant cells, tissues, and organs can be cultured under controlled conditions in glass or plastic vessels with defined growth media. Plant cells have three key abilities - totipotency, dedifferentiation, and competency - that allow regeneration of whole plants in tissue culture. The ratio of auxin and cytokinin plant hormones can determine whether roots or shoots develop. Somatic embryogenesis is described as the formation of embryo-like structures from somatic cells that can develop into whole plants similarly to zygotic embryos.
Synthetic seeds are encapsulated somatic embryos or shoot buds that can be used for planting like traditional seeds. They allow for clonal propagation of plants that are difficult to reproduce through traditional seeds, including some fruit crops. The production of synthetic seeds involves inducing somatic embryogenesis in callus cultures, maturing the embryos, and encapsulating them in a protective gel before planting. This allows genetic material to be stored and dispersed while avoiding issues with seed-borne diseases, low seed viability, and difficulties reproducing species that lack traditional seeds.
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.
Hormones play important roles in developing seeds. Auxins promote seed and fruit growth and are found in the embryo and endosperm. Gibberellins levels peak during embryo growth and decline at maturity. Cytokinins levels also rise during seed tissue growth. Abscisic acid concentration increases during seed development and declines at desiccation, establishing dormancy. Ethylene helps regulate seed germination. Hormone levels precisely regulate seed development, germination, and dormancy.
This document outlines the steps for in vitro plant regeneration: 1) preparing media, 2) selecting explant tissue, 3) establishing explants in media, 4) developing callus tissue, 5) developing plantlets, 6) hardening plants, and 7) planting in open fields. It also discusses using immature inflorescence, scutellar tissue from immature seeds, epidermis, and procambial tissue as explants for producing somatic embryos in plants like common wheat.
In vitro seed production and seed immobilizationPreeti Beniwal
Determination of Mung bean seed viability.
Preparation of various stock solutions of MS medium.
In Vitro Seed Germination of Mung bean.
Artificial Seed Production through Sodium Alginate immobilization technique
1. The document discusses biotechnology applications for horticultural crops including genetically modified organisms. It describes techniques like genetic engineering, tissue culture, embryo culture and haploid breeding that can be used to develop new crop varieties.
2. Examples of traits that can be improved through biotechnology include increased yield, pest and disease resistance, and improved postharvest qualities. The document lists some GM crops that have been approved or are undergoing field tests.
3. The challenges of tropical fruit export and postharvest storage are discussed. Controlling ethylene production and perception genes could help extend shelf life of fruits like mango to increase export potential. Precision genome editing techniques may allow targeting of genes with more specificity.
Somatic embryogenesis and artificial seed productionArvind Yadav
This document discusses somatic embryogenesis and artificial seed production. It describes the two main types of somatic embryogenesis (indirect and direct), the steps involved in the process, and factors that affect it such as genotype, explant type, growth regulators, and nitrogen source. It also covers embryo maturation, secondary somatic embryogenesis, synchronization of embryo development, and production of artificial or synthetic seeds by encapsulating somatic embryos. The goal is large-scale clonal propagation of plants through synthetic seed technology.
germination of seed.
the slides are prepared to provide a short but valuable concept about seed germination and different conditions associated with it.
The document provides an introduction to artificial seeds, including definitions and key concepts. It discusses the two main types of artificial seeds - desiccated and hydrated synthetic seeds. The production process involves establishing somatic embryogenesis, encapsulating somatic embryos or shoot buds, and planting the artificial seeds. Alginate is commonly used as the encapsulating material. Additives can be included to the matrix to serve as an artificial endosperm. The document outlines the potential uses and benefits of artificial seeds for propagation, germplasm preservation, and genetic engineering applications.
Light is a major environmental factor that influences seedling development. During seed germination, light controls whether seedlings develop normally (de-etiolation) or abnormally in the dark (etiolation). In the dark, seedlings undergo etiolation with limited organ development and no chlorophyll production. When exposed to light, seedlings undergo de-etiolation where they develop properly with chlorophyll synthesis and organ development. This process of de-etiolation from the etiolated state to normal growth is triggered by light and involves photoreceptors such as phytochromes that detect light and induce changes in seedling development.
This document provides an introduction and overview of the book "Seed Germination Theory and Practice" by Norman C. Deno.
The book aims to provide concise directions for optimizing the germination of nearly 2,500 plant species based on extensive experiments conducted by the author. It also discusses the underlying principles of seed germination from a mechanistic chemical perspective.
The book is intended to be useful for plant growers by providing practical germination methods, as well as for biologists and chemists by exploring seed germination as a complex chemical process that can be studied using techniques from those fields. The author encourages an open and experimental approach to germinating different plant species using efficient new methods described in the book
Artificial Seed - Definition, Types & Production ANUGYA JAISWAL
Artificial seeds, also known as synthetic seeds, involve the encapsulation of somatic embryos, shoot buds, or cell aggregates to propagate plants in vitro or ex vivo. They were first introduced in the 1970s and provide advantages like large-scale and low-cost propagation while maintaining genetic uniformity. Successful artificial seeds require an embryo-protective coating containing nutrients to support germination and growth. The coating material, embryo maturity, and encapsulation process can produce either desiccated or hydrated synthetic seeds. Common steps in artificial seed production involve establishing embryogenesis, encapsulating mature embryos, and field planting.
Tissue culture is a technique that grows plant cells, tissues or organs in an artificial nutrient medium under sterile conditions. The basic requirements for tissue culture include various inorganic and organic nutrients, vitamins, amino acids, sucrose as a carbon source, and plant growth regulators. The inorganic nutrients include macro and micronutrients that provide minerals for growth. The medium is solidified with a gelling agent like agar and adjusted to pH 5.8 before autoclaving. Stock solutions of ingredients are prepared in advance and mixed as needed to prepare the culture medium under sterile conditions.
This document discusses seed propagation techniques in fruit and plantation crops. It covers sexual propagation starting with seed formation through fertilization and development of the zygote into an embryo. The process of seed germination including imbibition, mitochondrial maturation, and radicle and plumule emergence is explained. Seed dormancy, types including exogenous, endogenous, and the processes to overcome dormancy are outlined. Commercial seed production in crops like phalsa, jamun, mangosteen, jackfruit, arecanut and coconut is mentioned, while propagation through other means than seeds is preferred for banana, pineapple, and strawberry.
8. Plant growth and development and dormancy.pptxUmeshTimilsina1
Plant growth involves cell division and enlargement leading to an increase in size, while development refers to the progression of a plant from one life stage to another through morphogenesis and differentiation. Growth follows a sigmoid curve with three phases - lag, exponential, and stationary. Fruit growth patterns include single, double, and triple sigmoid curves. Seed dormancy allows seeds to disperse and survive unfavorable conditions, while bud dormancy helps plants withstand cold weather. Dormancy can be overcome through scarification, stratification, hormone treatments, and other methods.
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.
Artificial seeds are encapsulated somatic embryos that can convert into plants under in vitro and ex vitro conditions. Somatic embryos are bipolar structures that can form shoots and roots. There are two types of artificial seeds: desiccated and hydrated. Desiccated seeds are hardened and encapsulated while hydrated seeds remain hydrated using gels like calcium alginate. Artificial seeds allow for large scale propagation of plants, including non-seed producing plants and plants with problems in seed propagation. However, more research is still needed to optimize artificial seed technology for commercial use.
This document provides information about a lecture on the introduction to basic biotechnology and its importance, prospects, scope and limitations in horticulture. The key points covered are:
1) Biotechnology can help meet the increasing global demand for food through techniques like genetic engineering that allow for direct gene transfer and faster crop improvement compared to conventional breeding.
2) Genetic engineering is being used to develop horticultural crops with traits like pest and disease resistance, higher yields, improved quality and processing. However, it is not part of organic farming.
3) Techniques discussed that are useful in horticultural crop improvement include tissue culture, embryo culture, protoplast fusion, in vitro mutation, synthetic seeds,
Tissue culture involves the use of small pieces of plant tissue (explants) which are cultured in a nutrient medium under sterile conditions. Tissue culture is in vitro maintenance and propagation of isolated cells tissues or organs in an appropriate artificial environment.
This document discusses triploid production through endosperm culture and somatic embryogenesis. It defines endosperm culture as the in vitro development of isolated mature or immature endosperm tissue to obtain triploid plantlets. Two types of endosperm culture are described: mature and immature. The key steps and factors affecting endosperm culture are outlined. Somatic embryogenesis is defined as the development of embryos from somatic cells in vitro. The document compares somatic and zygotic embryos and describes the two routes of somatic embryogenesis: direct and indirect. The stages of somatic embryogenesis and factors influencing the process are summarized.
This document discusses in vitro plant breeding techniques. It describes how plant cells, tissues, and organs can be cultured under controlled conditions in glass or plastic vessels with defined growth media. Plant cells have three key abilities - totipotency, dedifferentiation, and competency - that allow regeneration of whole plants in tissue culture. The ratio of auxin and cytokinin plant hormones can determine whether roots or shoots develop. Somatic embryogenesis is described as the formation of embryo-like structures from somatic cells that can develop into whole plants similarly to zygotic embryos.
Synthetic seeds are encapsulated somatic embryos or shoot buds that can be used for planting like traditional seeds. They allow for clonal propagation of plants that are difficult to reproduce through traditional seeds, including some fruit crops. The production of synthetic seeds involves inducing somatic embryogenesis in callus cultures, maturing the embryos, and encapsulating them in a protective gel before planting. This allows genetic material to be stored and dispersed while avoiding issues with seed-borne diseases, low seed viability, and difficulties reproducing species that lack traditional seeds.
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.
Hormones play important roles in developing seeds. Auxins promote seed and fruit growth and are found in the embryo and endosperm. Gibberellins levels peak during embryo growth and decline at maturity. Cytokinins levels also rise during seed tissue growth. Abscisic acid concentration increases during seed development and declines at desiccation, establishing dormancy. Ethylene helps regulate seed germination. Hormone levels precisely regulate seed development, germination, and dormancy.
This document outlines the steps for in vitro plant regeneration: 1) preparing media, 2) selecting explant tissue, 3) establishing explants in media, 4) developing callus tissue, 5) developing plantlets, 6) hardening plants, and 7) planting in open fields. It also discusses using immature inflorescence, scutellar tissue from immature seeds, epidermis, and procambial tissue as explants for producing somatic embryos in plants like common wheat.
In vitro seed production and seed immobilizationPreeti Beniwal
Determination of Mung bean seed viability.
Preparation of various stock solutions of MS medium.
In Vitro Seed Germination of Mung bean.
Artificial Seed Production through Sodium Alginate immobilization technique
1. The document discusses biotechnology applications for horticultural crops including genetically modified organisms. It describes techniques like genetic engineering, tissue culture, embryo culture and haploid breeding that can be used to develop new crop varieties.
2. Examples of traits that can be improved through biotechnology include increased yield, pest and disease resistance, and improved postharvest qualities. The document lists some GM crops that have been approved or are undergoing field tests.
3. The challenges of tropical fruit export and postharvest storage are discussed. Controlling ethylene production and perception genes could help extend shelf life of fruits like mango to increase export potential. Precision genome editing techniques may allow targeting of genes with more specificity.
Somatic embryogenesis and artificial seed productionArvind Yadav
This document discusses somatic embryogenesis and artificial seed production. It describes the two main types of somatic embryogenesis (indirect and direct), the steps involved in the process, and factors that affect it such as genotype, explant type, growth regulators, and nitrogen source. It also covers embryo maturation, secondary somatic embryogenesis, synchronization of embryo development, and production of artificial or synthetic seeds by encapsulating somatic embryos. The goal is large-scale clonal propagation of plants through synthetic seed technology.
germination of seed.
the slides are prepared to provide a short but valuable concept about seed germination and different conditions associated with it.
The document provides an introduction to artificial seeds, including definitions and key concepts. It discusses the two main types of artificial seeds - desiccated and hydrated synthetic seeds. The production process involves establishing somatic embryogenesis, encapsulating somatic embryos or shoot buds, and planting the artificial seeds. Alginate is commonly used as the encapsulating material. Additives can be included to the matrix to serve as an artificial endosperm. The document outlines the potential uses and benefits of artificial seeds for propagation, germplasm preservation, and genetic engineering applications.
Light is a major environmental factor that influences seedling development. During seed germination, light controls whether seedlings develop normally (de-etiolation) or abnormally in the dark (etiolation). In the dark, seedlings undergo etiolation with limited organ development and no chlorophyll production. When exposed to light, seedlings undergo de-etiolation where they develop properly with chlorophyll synthesis and organ development. This process of de-etiolation from the etiolated state to normal growth is triggered by light and involves photoreceptors such as phytochromes that detect light and induce changes in seedling development.
This document provides an introduction and overview of the book "Seed Germination Theory and Practice" by Norman C. Deno.
The book aims to provide concise directions for optimizing the germination of nearly 2,500 plant species based on extensive experiments conducted by the author. It also discusses the underlying principles of seed germination from a mechanistic chemical perspective.
The book is intended to be useful for plant growers by providing practical germination methods, as well as for biologists and chemists by exploring seed germination as a complex chemical process that can be studied using techniques from those fields. The author encourages an open and experimental approach to germinating different plant species using efficient new methods described in the book
Artificial Seed - Definition, Types & Production ANUGYA JAISWAL
Artificial seeds, also known as synthetic seeds, involve the encapsulation of somatic embryos, shoot buds, or cell aggregates to propagate plants in vitro or ex vivo. They were first introduced in the 1970s and provide advantages like large-scale and low-cost propagation while maintaining genetic uniformity. Successful artificial seeds require an embryo-protective coating containing nutrients to support germination and growth. The coating material, embryo maturity, and encapsulation process can produce either desiccated or hydrated synthetic seeds. Common steps in artificial seed production involve establishing embryogenesis, encapsulating mature embryos, and field planting.
Tissue culture is a technique that grows plant cells, tissues or organs in an artificial nutrient medium under sterile conditions. The basic requirements for tissue culture include various inorganic and organic nutrients, vitamins, amino acids, sucrose as a carbon source, and plant growth regulators. The inorganic nutrients include macro and micronutrients that provide minerals for growth. The medium is solidified with a gelling agent like agar and adjusted to pH 5.8 before autoclaving. Stock solutions of ingredients are prepared in advance and mixed as needed to prepare the culture medium under sterile conditions.
This document discusses seed propagation techniques in fruit and plantation crops. It covers sexual propagation starting with seed formation through fertilization and development of the zygote into an embryo. The process of seed germination including imbibition, mitochondrial maturation, and radicle and plumule emergence is explained. Seed dormancy, types including exogenous, endogenous, and the processes to overcome dormancy are outlined. Commercial seed production in crops like phalsa, jamun, mangosteen, jackfruit, arecanut and coconut is mentioned, while propagation through other means than seeds is preferred for banana, pineapple, and strawberry.
8. Plant growth and development and dormancy.pptxUmeshTimilsina1
Plant growth involves cell division and enlargement leading to an increase in size, while development refers to the progression of a plant from one life stage to another through morphogenesis and differentiation. Growth follows a sigmoid curve with three phases - lag, exponential, and stationary. Fruit growth patterns include single, double, and triple sigmoid curves. Seed dormancy allows seeds to disperse and survive unfavorable conditions, while bud dormancy helps plants withstand cold weather. Dormancy can be overcome through scarification, stratification, hormone treatments, and other methods.
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.
Seed dormancy is a state where seeds are prevented from germinating under normally favorable conditions. There are two main categories of dormancy - exogenous caused by external factors like a hard seed coat, and endogenous caused by internal factors in the embryo. Dormancy allows seeds to delay germination until conditions are suitable to increase the likelihood of seedling survival. Various natural and artificial methods can be used to break dormancy. Dormancy provides biological benefits like allowing seeds to survive unfavorable periods and disperse to new areas.
This document covers seed germination, dormancy, and storage. It discusses the environmental requirements for germination, including moisture, temperature, light, and oxygen. It describes the three stages of germination - imbibition, lag phase, and emergence phase. It defines epigeal germination, exemplified by French beans, and hypogeal germination, exemplified by broad beans. Methods to break seed dormancy include scarification, soaking, and stratification. Long term seed storage aims to control respiration rates to maintain seed viability over time.
Seed dormancy refers to seeds not germinating during unsuitable conditions for seedling survival. There are three main types of dormancy - physical, physiological, and morphological. Dormancy prevents germination through impermeable seed coats, immature embryos, or germination inhibitors. Common methods to break dormancy include scarification, stratification, light exposure, and chemical treatments like gibberellic acid soaking. These treatments help prepare the seed and environment for successful germination.
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.
This document discusses seed dormancy, including its definition, types, and mechanisms. It begins with definitions of dormancy as a block to seed germination under favorable conditions. There are three main types of primary dormancy discussed: exogenous (caused by external factors like the seed coat), endogenous (caused by internal factors like the embryo), and combinations of these. Secondary dormancy can be induced by unfavorable conditions after seed dispersal. The mechanisms of dormancy include physical, chemical, and morphological barriers imposed by the seed or its coat. Factors that affect dormancy breaking are also summarized. The document concludes by discussing the significance and problems caused by seed dormancy in horticulture.
The document discusses plant growth, development, and reproduction. It begins by defining plant growth and differentiation. It then describes the stages of plant development from seed germination through flowering and fruiting. The remainder of the document addresses the processes involved in seed formation, seed germination, shoot formation, root formation, and flower formation at the cellular and molecular level. Diagrams are provided to illustrate key concepts and structures.
Pollination, fertilization, and seed dispersal are key stages in plant reproduction. [1] Pollination involves the transfer of pollen from the anther to the stigma. [2] Fertilization occurs after pollination, when the pollen tube delivers sperm to fertilize the egg. [3] Seed dispersal is the movement of seeds away from the parent plant.
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.
This presentation will led you to a good knowledge about the seed dormancy , its breaking methods and importance . Its an educational material delivered by me in my college presentation.
This document discusses seed dormancy, including its types and causes. It begins by defining dormancy and seed dormancy. There are five main types of seed dormancy: physiological, morphological, morpho-physiological, physical, and combinational. Seed dormancy can be caused by an impermeable seed coat, an underdeveloped or inhibited embryo, specific light or temperature requirements, or natural germination inhibitors within the seed or fruit.
Seed germination begins when a seed absorbs water and swells. Enzymes are activated which break down stored food to provide energy for growth. The radicle emerges first, followed by the plumule. Germination requires favorable conditions like water, oxygen, temperature and sometimes light. There are two types of germination - epigeal where the seed leaves emerge above ground and hypogeal where they remain underground. Factors like water, temperature, light, soil conditions and the seed's maturity and dormancy affect whether and how quickly it will germinate.
This document discusses seed dormancy, including its types, causes, and how it can be overcome. It defines dormancy as a temporary suspension of growth and explains that seed dormancy prevents germination under favorable conditions. The types of dormancy discussed are coat-induced dormancy, embryo-induced dormancy, and physiological, morphological, morpho-physiological, physical, and combinational dormancy. The causes of seed dormancy include hard seed coats, underdeveloped or inhibited embryos, light or temperature requirements, and natural germination inhibitors. Overcoming dormancy may involve scarification, stratification, photoperiod exposure, or after-ripening to allow germination.
Dormancy is when there is a lack of germination in seeds or tubers even though the required conditions (temperature, humidity, oxygen, and light) are provided. Dormancy is based on hard seed coat impermeability or the lack of supply and activity of enzymes (internal dormancy) necessary for germination. Dormancy is an important factor limiting production in many field crops. Several physical and chemical pretreatments are applied to the organic material (seeds/tubers) to overcome dormancy. Physical and physiological dormancy can be found together in some plants, and this makes it difficult to provide high-frequency, healthy seedling growth, since the formation of healthy seedlings from the organic material (seeds/tubers) sown is a prerequisite for plant production. This chapter will focus on the description of four different methods we have not seen reported elsewhere for overcoming dormancy.
Dormancy is a state where seeds lack germination even when conditions are suitable. It is caused by impermeable seed coats or lack of enzymes for germination. This chapter discusses four new methods for overcoming dormancy: exposing seeds to magnetic fields, treating with squirting cucumber fruit juice, sodium hypochlorite solutions, and gamma radiation. Fruit trees must be propagated vegetatively by grafting or budding as seeds will produce hybrids unlike the parent fruit. Seeds require chilling periods before germination and there are several methods described for growing fruit trees from seed.
Similar to Seed and Seed Production Notes L400 (20)
1. Seed Physiology: A Brief Primer
I. Structure / Function
A. Seed Function
1. propagation of plant
2. mechanism for offspring dispersal
3. protect immature plant in adverse conditions
B. Definitions
• A fancy botanical definition for a seed: a ripened ovule
• Steve’s simplistic definition: a baby in a suitcase carrying its lunch
C. Parts
1. The Baby = Embryo
• The embryo is essentially an immature, undeveloped plant
• derived from zygote
• The main parts of the embryo are the radicle (develops into the root), epicotyl (develops into
the shoot), hypocotyl (embryonic stem connecting radicle and epicotyl), cotyledons (seed
"leaves" - usually for food storage).
2. Suitcase = Seed coat. This represents the outer protective layer, derived from the integuments of
the ovule.
3. Lunch = stored reserves
• provide nutrients for the germinating seedling
• various kinds of reserves depending upon the plant: starch (cereals), fats & oils (nuts, soybean),
protein (legumes)
• amount of stored reserves varies (lots in cereals, legumes) to little (orchids provide virtually no
reserves, which means the seedlings rely on a symbiotic relationship with fungi immediately on
germination to support the seeds).
D. Seed Types - there are three major kinds based on embryo structure and how metabolize
endosperm. Note that there are many variations and intermediate forms
• monocot (cereal)
• eudicot with endosperm
• eudicot without endosperm (endosperm is metabolized and stored in cotyledons, i.e., beans)
II. Seed Formation - Seed formation is initiated upon pollination/fertilization. The general pattern of
activities: embryo formation → reserves stored → water loss
1. Embryo formation is the first stage. The zygote develops into the embryo. During this stage there
is lots of cell division, synthesis of DNA, RNA and proteins, and endosperm formation.
2. 2. Once the basic embryo forms, growth stops and then reserves accumulate. Growth inhibitors
synthesized during latter part of the phase
3. Dehydration - seed looses water, mature seeds with less than 10% water; seed coat sclerifies
(becomes hard & dry) for added protection
III. Dormancy
A. Definition
• dormant - suspended animation; won’t germinate even if conditions are favorable (innate
dormancy)
• quiescence (enforced dormancy) – doesn’t germinate because conditions aren’t favorable
(i.e., missing one of the requirements for germination such as water).
• primary – dormant immediately at harvest
• secondary (induced dormancy) – can germinate initially, but if exposed to adverse conditions
(cold, low oxygen, high temp) will become dormant
B. Are seeds alive?
• inactive metabolism, unable to detect
• viable vs. dead?
• Germination Percentage = # seeds germ/total * 100
• Germination Rate %germ vs. time (quicker better – sooner to photosynthesize, shorter growing
time, uniform stand vs. uneven crop)
• Viability Tests: (a) sow, (b) tetrazolium, (c) float, (d) cut open embryo
C. Function
• withstand environmental extremes (e.g., cold, heat, radiation, microwaves)
o loose water during development (dry to less than 10% moisture)
o prevents ice formation
o inactivates metabolism
• increase longevity - variable storage survival rates – few months to many years (10,000 arctic
lupine); longest lived seeds with hard heavy coat or weeds; crops generally short viability
• provides time for dispersal
• key feature distinguishes plants and animals - animals have no dormant period, undergo
continuous development
• viviparous – a few with no dormancy, uncommon (i.e., mangrove), mutation in some
D. Dormancy Mechanisms
1. Mechanical (heavy impervious seed coat) – scarification to break (file), acid, rotating drum with
sandpaper (e.g., honey locust, morning glory,)
2. Chemical (inhibitors) – removed by washing out, chilling (e.g., ABA in ash other seeds, citric acid
in tomatoes)
3. After-ripening (immature undeveloped embryos) – require growth period after being shed from
plant (e.g., carrots, parsnips, hemp).
4. Physiological inhibition
(a) Light. Stimulates many (esp. small seeds) or inhibits (uncommon) or no effect. Acts via
phytochrome, red light absorbing pigments, alternates between two forms)
(b) Ethylene - larger seeds
(c) Cold - stratification, e.g., apples
(d) Heat treatments for desert and winter annuals (germinate after warm summer)
(e) Alternating temperatures - hot/cold; e.g., evening primrose, tobacco; mechanical
3. change in seed coat or other mechanism; epicotyl dormancy - root emerges in warm temp,
epicotyl requires cold, gives time for root to develop before epicotyl, e.g., wild ginger, waterleaf
5. Fire - increases light by reducing competition, destroy inhibitors in soil, charred remains stimulate,
smoke stimulates - habitats that are seasonally dry and adapted to periodic burning (e.g.,
chaparral in CA, prairie in MN)
IV. Germination
A. Requirements
1. Water
• Absorption of water is called imbibition. Seeds can absorb up to 200% of its weight and
more than double its volume. Initially quick, slows, then followed by more rapid absorption;
too fast damages cells, no time for 'repair'.
• Embryo expansion provides force to rip open seed coat (which swells less). Generates lots of
force (used to be used to quarry stone)
• Water uptake is passive - due to affinity of water for seed components (adhesion/cohesion)
and water potential gradients.
• Function of water: (1) softens seed coat; (2) provides force to open; (3) activates dormant
enzymes and stimulates synthesis of new ones; (4) solubilizes seed components; (5) dilutes
inhibitors; (6) provides force for cell growth.
2. Oxygen
• Oxygen uptake very slow initially, then rapidly after imbibition
• required for oxidative reactions (i.e., respiration & ATP production)
• switch from anaerobic to aerobic metabolic key regulatory step during germination
3. Temperature
• Affects rates of chemical reactions (recall the graph of reaction rate vs. temp for an
enzymatic reaction)
• Dry seeds withstand broad range of temperatures
• Hydrated seeds (after imbibition occurs) can tolerate only a narrow range
• Species vary in response to temp (minimal temp, maximal temp, optimal temp) for
germination.
• Temperature also influences things other than reaction rates. For example, if treat lima
beans at 5 C for first half hour of imbibition, it depresses respiration and the embryo dies with
5 days - due to temp sensitivity of membranes. Cold makes them leaky, cold tolerant
species don't leak.
4. Suitable stored reserves (foodstuffs)
• provide (a) carbon skeletons, (b) fuel source for respiratory energy (ATP)
• germination is initially heterotrophic. Consider graph of weight of seedling over time.
• food reserves in polymeric form – requires conversion to monomeric form and then
transported to sites of need
• hydrolytic enzymes activated or synthesized
5. Dormancy broken (chemical treatments to encourage seeds; e.g., GA, potassium nitrate)
4. 6. Suitable substrate - no inhibitors or allelopathic agents present; medium contains sufficient
moisture, oxygen, etc.
B. Chronology of Events
1. Imbibition
2. Appearance of metabolic activity - early activities: primarily to get seed ready for metabolism &
growth, later events involved in utilization of stored reserves for new synthesis
Table: Temperature Ranges for Germination of Various Seeds (data from
Noggle & Fritz)
Species Temperature ( C )
Minimum Optimum Maximum
wheat 3-5 15-31 30-43
maize 8-10 32-35 40-44
cantelope 10-19 30-40 45-50
mustard 0.5-3 20-35 35-40
3. Radicle (root) emergence - now considered a seedling (germination starts at imbibition and
ends at radicle appearance
IV. Molecular Biology of Barley Seed Germination
Gibberellic acid (GA), which is one of the plant hormones, is produced by the scutellum
(cotyledon) of the embryo stimulates the production of amylase by the aleurone layer amylase
hydrolyzes starch to simple sugars absorbed by scutellum and translocated to embryo for growth.
The production of amylase occurs de novo. That is, gibberellin stimulates transcription. In short:
GA binds to membrane receptor interacts with a protein complex (heterotrimeric G protein) that
activates a GA signaling intermediate turns off a repressor transcription of GA-MYB mRNA
translated in cytosol to make GA-MYB protein returns to nucleus to bind to alpha-amylase gene
promoter region activates transcription of alpha-amylase mRNA translated in ribosomes on RER
transported to golgi secretory vesicles release alpha-amylase. This last step is apparently regulated by
a calcium dependent mechanism that was also activated by the heterotrimeric G protein complex.
Brewers take advantage of GA's ability to stimulate germination and enzymes which are
important in the brewing process.
see overhead
V. Planting seeds
1. Depth - no deeper than length or 3x the average diameter, shallower is better than deeper
2. Plant more than you think you need - not all will germinate (can’t tell if dead, dormant or
quiescent)
3. Thin as necessary - too much competition. Can you design an experiment to test the
importance of thinning?
4. Methods - Petri dish, pots, rag dolls, germination paper
5. Timing – important
a. Cool Season (40 – 55 F or 4.4. – 13 C) – radish, lettuce, spinach, Swiss chard, beet, carrot,
onion, cauliflower, cabbage, broccoli, kohlrabi, kale, turnips, rutabagas, peas,
snapdragons, pansies
5. b. Warm season (> 60 F) - tomato, egg plant, pepper, cucumber, squash, watermelon,
cantalope snap bean, lima bean, sweet corn, marigold, zinnia
6. Seed bed prep - uniform eliminate clods to get good contact between seed and soil, free from
weeds
7. When to plant indoors - transplants put out after the average last killing frost (in late May).
Tomato require about six weeks, annual flowers 6 – 8 weeks; cool season - sow outside as soon as
work soil
VI . Seedlings
1. first leaves
2. hook vs. sheath (dicot vs. monocot)
3. adult vs. juvenile
4. epigaeous vs. hypogaeous
5. behavior - circumnutation