Seeds and seed germination

1
Seeds and seed germination major seed
structures seed coat endosperm embryo seed
coat - functions to provide protection to the
embryo
2
embryo - is the offspring plant - all
structures in the mature plant originate in the
embryo endosperm - is
a nutritive tissue
3
embryo structure and growth pattern - vary
with the plant species embryo structure floweri
ng plant embryos always include a radicle
a plumule including an epicotyl
and leaf primordia one or two cotyledons
- are another location where
nutrients may be stored (one cotyledon in
monocots two cotyledons in dicots)
4

the radicle and plumule on opposite ends of
root-shoot axis - separated by a hypocotyl
region seed germination and early seedling
growth may be epigeous OR
hypogeous
5
embryos of grasses include additional
structures coleoptile coleorhiza
- protect the root/shoot apical meristems during
germination
6
in plants other than grasses, - the shoot
apical meristem may be protected by a hook in
the epicotyl or hypocotyl
- hooked epicotyl is usually associated with
hypogeous germination
- hooked hypocotyl is usually associated with
epigeous germination
7
seeds generally store the majority of nutrients
in either the endosperm or the cotyledons, not
both albuminous seeds exalbuminous seeds