v.seeds Flashcards
- A ripened ovule which when shed from the parent plant
- consist of embryo and stored food supply both of which are enclosed in a seed coat or covering.
Seed
– embryo lies within an axis of two cotyledons
Dicotyledon
– consist of seed coat, endosperm and embryo
Monocotyledon
– developing plant still inside the seed. The embryo has cotyledons (embryonic leaves), a root cap, a food source and a plumule (shoot)
- Embryo
– the scar on seed coat at the location where it was attached to the plant’s stalk during development
- Hilum
– the small pore in a seed that allows water absorption
- Micropyle
– the part of the stem of a sprouting plant that is above the root and below the stalk of the cotyledon (seed leaves).
- Root (Hypocotyl)
is the outer, protective layer covering the seed.
- Seed coat (Testa) –
– the embryonic leaf within a seed
- Seed leaf (cotyledon)
– the shoot of an embryo
- Plumule
- Dries out naturally on mother plant to a low moisture content (less than 20%)
- Can be dried to low moisture content (less than 5%) without damage
- Can be stored at low temperature
- Ex. Rice, corn, beans, vegetable seeds, pili, etc.
- Orthodox(Types of Seed)
- Do not dry out normally on mother plant, shed in moist condition (50-70%MC)
- Seed larger than orthodox-embryo is only 15% of the orthodox
- Killed if MC is reduced below critical values (12-30%)
- Susceptible to freezing or chilling
- Ex. Seeds of aquatic species, large seeded species, wild rice, tropical fruit crops, jackfruit, cacao, rambutan, lanzones, etc.
- Recalcitrant (Types of Seed)
(Types of Seed)
* Can withstand desiccation to about 10-12%MC and can be stored under hermetic condition
* Lose viability more rapidly at low temperature (below 10 degree celcius) than a warm temp (12-21 degree celcius)
* Ex. Coffee, oil palm, papaya, citrus, star apple, chico, etc.
Intermediate
