seed physiology
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Seed germination is the process by which a seed emerges from dormancy to sprout and grow into a seedling. A seed contains an embryo plant and food reserves to fuel initial growth. The germination rate describes the percentage of seeds that will germinate under proper conditions, and is useful for crop planning. Seed germination is influenced by external factors like water, temperature, oxygen, and light as well as internal factors.
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A seed is a small embryonic plant enclosed in a protective seed coat that contains stored food. Seeds allow plants to maintain dormancy until conditions are suitable, protect the vulnerable young plant, provide food until photosynthesis is possible, and aid in plant dispersal. The main structures of a seed include the seed coat, hilum, embryo containing cotyledon, epicotyl/hypocotyl, plumule, and radicle. The seed coat protects the embryo while the cotyledon stores food and the epicotyl/hypocotyl and radicle form the basis of the stem and root.
Organogenesis
Organogenesis is the process by which the three germ layers (ectoderm, endoderm, and mesoderm) develop into internal organs through proliferation, migration, reaggregation and differentiation of cells. This process occurs between weeks 3 to 8 of development in utero. During this critical period, environmental factors can greatly impact development by disturbing key processes like cell division, apoptosis, gene expression and metabolism. Exposure to teratogens during organogenesis raises the risk of birth defects and structural abnormalities, while exposure later in pregnancy is less likely to cause such defects.
Animal development
Fertilization involves the combining of haploid sets of chromosomes from two individuals into a zygote. This is followed by cleavage, where rapid cell division occurs. Then gastrulation takes place, where cells migrate to locations that will form organs and tissues. Finally, organogenesis occurs, where organ rudiments develop from the three germ layers.
Animal Development
1. The document outlines the early stages of animal development from fertilization through gastrulation and organogenesis. It describes the formation of the blastula and gastrula, and the three germ layers that give rise to organs.
2. Morphogenesis and cell differentiation are discussed, involving changes in cell shape, position, and adhesion guided by the extracellular matrix and cell signaling molecules.
3. Fate mapping reveals how specific regions of early embryos develop into particular structures later. Cytoplasmic determinants in vertebrate eggs help establish axes and cell differences, influencing pattern formation through inductive signals that vary by location.
Processes on animal development
The document discusses early concepts of development including preformation versus epigenesis. It was once thought that the embryo was preformed in the egg, but experiments demonstrated that undifferentiated material in the egg becomes arranged through epigenesis. Key developmental stages are described including fertilization, cleavage, blastula formation, and gastrulation which establishes the three germ layers. Differences in protostome and deuterostome development are outlined, focusing on differences in cleavage, fate determination, and body axis formation. The role of induction in patterning the embryo is also summarized.
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growth stages of wheat
Wheat is a staple food for 35% of the world's population. It has important growth stages from emergence to physiological maturity including germination, tillering, booting, heading, flowering, and grain filling. Phenological studies observe the timing and duration of these growth stages, which can vary depending on genotype, temperature, day length, and sowing date. Understanding wheat development and growth stages is important for agronomic management practices.
Seed Dormancy
Seed dormancy refers to seeds that fail to germinate under favorable conditions. There are several types of dormancy, including physical, chemical, and physiological dormancy. Proper treatments must be applied to break dormancy and induce germination. While dormancy allows seeds to withstand adverse conditions, it can also cause problems for agriculture by preventing uniform germination and the emergence of weeds in cultivated fields."
Germination of seed by kader mullah
germination of seed.
the slides are prepared to provide a short but valuable concept about seed germination and different conditions associated with it.
Plant growth and movement excellent.pptx
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.
Seed Germination.pptx
The document summarizes the process of seed germination. It explains that seeds contain an embryo with miniature organs protected by a seed coat. Germination begins when the seed absorbs water, activating enzymes that break down stored starches into sugars used for growth. The seed coat then ruptures as the radicle and plumule emerge. Germination requires sufficient water, oxygen, light, and temperature to fuel cell division and the growth of the embryonic roots and leaves into a seedling. Various factors like dormancy, vernalization, and phenolic compounds regulate the timing of germination.
5ASeedGermination.pptx
The document summarizes the process of seed germination. It explains that seeds contain an embryo with miniature organs and stored food. For germination to occur, the seed coat must absorb water which activates enzymes to break down stored food into sugars for energy. This allows cell division and the emergence of the radicle root. Factors like water, light, oxygen, and temperature influence the rate and success of germination.
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1. Seed dormancy can occur due to hard seed coats, underdeveloped embryos, chemical inhibitors in seeds, or internal physiological factors in embryos.
2. Dormancy can be overcome through mechanical or chemical treatments like scarification, stratification, or gibberellic acid application.
3. Seeds have varying lifespans depending on moisture content - orthodox seeds can be dried while recalcitrant seeds lose viability when dried.
The Principles and Practices of Organic Radish Seed Production in the Pacific...
This document provides information on organic radish seed production in the Pacific Northwest. It discusses the basic biology and lifecycle of radishes and requirements for growing, selecting, isolating, harvesting, and cleaning radish seed crops. Key points covered include planting methods, spacing, selection criteria like seedling vigor and root shape/color, and maintaining a minimum population size of 120-200 plants to preserve genetic diversity. Diseases, insects, and post-harvest processing are also outlined.
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This document provides information on organic bean seed production in the Pacific Northwest. It discusses the basic biology and lifecycle of common beans, as well as requirements for growing bean seed such as climate, soil, fertility, planting, cultivation, flowering and pollination. It also covers isolation requirements, genetic maintenance and improvement, harvesting, and common diseases that affect bean seed crops. The overall goal is to support the ethical development and stewardship of bean seed through organic practices.
Seed dormancy
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
Factor affecting of seed germination
External factors like water, temperature, aeration, light, salinity, and pathogens can influence seed germination and seedling growth. Seeds need sufficient water and oxygen to germinate. The optimum temperature varies by species. Salinity and pathogens can prevent germination. Some seeds also have internal dormancy factors like an impermeable seed coat or lack of hormones and enzymes that need to be released through treatments like gibberellic acid or stratification before the seed can germinate.
Seed viability of different crops
This document provides an overview of seed viability and factors that affect it. It defines what a seed is and describes seed development. Seed viability is the ability of a seed to germinate and produce a normal seedling. It is highest at physiological maturity and declines over time. Factors like moisture content, temperature, relative humidity, mechanical damage, and storage fungi can impact seed viability during development and post-harvest storage. The document also discusses methods to test seed viability, such as germination tests and tetrazolium tests.
2012 sesame producer_guide_13_feb
This document provides a guide for producing sesame. It discusses advantages of growing sesame, including its drought tolerance and ability to grow in soils where other crops fail. It covers topics like field selection, planting considerations, growth stages, moisture and nutrient needs, pests, and harvest. Sesame is heat tolerant and can be grown across the southern US. Proper soil moisture, fertility, and temperature influence the length of development stages from germination to harvest. The guide aims to help producers successfully grow and manage sesame crops.
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Seed dormancy
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.
8. Plant growth and development and dormancy.pptx
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.
Advanced production technology.pptx
1) Lettuce is an important vegetable crop grown in temperate and tropical countries. It originated in the Mediterranean region and was spread throughout Europe by Greek and Roman civilizations.
2) There are several varieties of lettuce including head varieties like butterhead and crisphead, as well as non-heading varieties like romaine, leaf, and stem lettuce.
3) Lettuce grows best in cool temperatures with adequate moisture and nutrients. It is commonly affected by fungal diseases like damping off and downy mildew as well as insects like aphids and cabbage loopers. Proper spacing, irrigation, fertilization and pest management are needed to maximize lettuce production.
Seed dormancy (Plant Physiology)
Seed dormancy is defined as a state in which seeds are prevented from germinating even under environmental conditions normally favorable for germination.
These conditions are a complex combination of water, light, temperature, gasses, mechanical restrictions, seed coats, and hormone structures.Seed is a ripe and fertilized ovule that encloses an embryo
It is the connecting link between parents and progeny.
Structurally seeds have four major components,
Seed coat or a protective envelope
Embryo
Reserve food and minerals which provide nourishment
Enzymes and hormones for the digestion of food and formation of new tissues during germination
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seed physiology
- 4. GERMINATION RATE:- IN AGRICULTURE AND GARDENING, THE GERMINATION RATE DESCRIBES HOW MANY SEEDS OF A PARTICULAR PLANT SPECIES, VARIETY OR SEED LOT ARE LIKELY TO GERMINATE. IT IS USUALLY EXPRESSED AS A PERCENTAGE, E.G., AN 85% GERMINATION RATE INDICATES THAT ABOUT 85 OUT OF 100 SEEDS WILL PROBABLY GERMINATE UNDER PROPER CONDITIONS. THE GERMINATION RATE IS USEFUL FOR CALCULATING THE SEED REQUIREMENTS FOR A GIVEN AREA OR DESIRED NUMBER OF PLANTS.
- 5. FACTOR AFFECTING OF SEED GERMINATION:- (A) EXTERNAL FACTOR (B) INTERNAL FACTOR
- 9. AFTER THE SEEDLING EMERGES FROM THE SEED COAT AND STARTS GROWING ROOTS AND LEAVES, THE SEEDLING'S FOOD RESERVES ARE TYPICALLY EXHAUSTED; AT THIS POINT PHOTOSYNTHESIS PROVIDES THE ENERGY NEEDED FOR CONTINUED GROWTH AND THE SEEDLING NOW REQUIRES A CONTINUOUS SUPPLY OF WATER, NUTRIENTS, AND LIGHT.
- 13. MANY SEEDS GERMINATE AT TEMPERATURES SLIGHTLY ABOVE ROOM-TEMPERATURE 60-75 0 F (16-24 C), WHILE OTHERS GERMINATE JUST ABOVE FREEZING AND OTHERS GERMINATE ONLY IN RESPONSE TO ALTERNATIONS IN TEMPERATURE BETWEEN WARM AND COOL. SOME SEEDS GERMINATE WHEN THE SOIL IS COOL 28-40 0 F (-2 - 4 0 C), AND SOME WHEN THE SOIL IS WARM 76-90 0 F (24-32 0 C). SOME SEEDS REQUIRE EXPOSURE TO COLD TEMPERATURES (VERNALIZATION) TO BREAK DORMANCY.
- 14. SEEDS IN A DORMANT STATE WILL NOT GERMINATE EVEN IF CONDITIONS ARE FAVORABLE. SEEDS THAT ARE DEPENDENT ON TEMPERATURE TO END DORMANCY HAVE A TYPE OF PHYSIOLOGICAL DORMANCY. FOR EXAMPLE, SEEDS REQUIRING THE COLD OF WINTER ARE INHIBITED FROM GERMINATING UNTIL THEY TAKE IN WATER IN THE FALL AND EXPERIENCE COOLER TEMPERATURES. FOUR DEGREES C IS COOL ENOUGH TO END DORMANCY FOR MOST COOL DORMANT SEEDS, BUT SOME GROUPS, ESPECIALLY WITHIN THE FAMILY RANUNCULACEAE AND OTHERS, NEED CONDITIONS COOLER THAN -5 0 C.