Seed Germination (2) Flashcards
characteristics of seed
- seed size
- seed color
- seed surface
types of seeds
- monocotyledonous seeds
- dicotyledonous seeds
based on the presence or absence of endosperm, seeds can be classified into:
- albuminous seeds (endospermic)
- exalbuminous seeds (non endospermic)
the outer covering of the endosperm be touches embryo by a proteinous layer
aleurone layer
the protected and differentiated sheath of the radical
coleorhiza
is an inner, thin, membranous covering that protects the inner part of the seed
tegman
it is a scar on the seat coat through which the developing seed is attached to the fruit
hilum
a small poor present above the hilum
micropyle
it is a ridge like structure present around the median groove
raphe
a young miniature plant is present between the two cotyledons
embryonal axis
is the mechanism that helps in the transport of seeds to other places to ensure the germination and survival of at least a few into the adult plants
seed dispersal
types of seed dispersal
- by wind (anemochory)
- by water (hydrochory)
- by animals (zoochory)
- by explosions (autochory)
according to type of stored substances, seeds divided into:
- cereals
- pulses
- oil seed
- spices
- beverage and medicine
- fibre
these seeds can survive extreme freezing or drying conditions during ex-citu conservation
orthodox seeds
they cannot thrive in freezing or dry conditions for a long duration
recalcitrant seeds
