Seeds

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Seeds
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Hilum
Soy beans
Pinto beans
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Arils
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Caruncle

• Castor seeds

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Storage tissue
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Seed layers - grain
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The Wheat Embryo its immediate Environs En
Endosperm, S Scutellum (Cotyledon) CN
Cotyledonary Node, RAM Root Apical Meristem,
RCap Root Cap, CR Coleorhiza, SC/PC Seed
Coat/Pericarp, SAM Shoot Apical Meristem, LP
Leaf Primordia, CT Coleoptile
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Corn caryopsis
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The Endosperm of cereals has two major regions.
The outer part is called the Aleurone Layer. Its
cells of  have prominent Nuclei. They contain
most of the oil extracted from corn. They also
contain a relatively large amount of Protein in
the form of "Aleurone Grains".
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Bean
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Water and food reserves
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Imbibition - 3 phases

• Phase I - Matric potential
• Phase II - holding
• Phase III - breakdown of storage into osmotically
  active compounds

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Germination
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Germination reactions
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• Changes during germination

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Dormancy

• Innate dormancy
• Induced dormancy
• Enforced dormancy

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Factors affecting dormancy

• Light
• Pfr needed for germination
• Tied to production of gibberellin

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Factors affecting dormancy

• Moisture
• Needs certain amount of rain
• Temperature
• Cold or warm treatment necessary
• Seed coat

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Gibberellin vs. ABA (absissic acid)

• Gibberellin plays a role in seed development
• In cereals
• Produced by embryo
• Triggers mRNA production - codes for a-amylase
  production
• ABA seems to override effect of GA - brings about
  dormancy
• Can be leeched from seed by water or overcome by
  sufficient quantities of GA

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Soybean