022 TYPES OF SEED GERMINATION IN DICOTYLEDONS

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Soak few bean seeds and peas in water
overnight. Take four paper cups or four halves of
empty coconut shells. Make a small hole at the
bottom of the cups. Alternatively while using the
coconut shells, of the three eyes (round
indentations), drill the soft eye. Fill them with
soil. Put 2 pre- soaked kidney beans in two
paper cups/coconut shells and put 2 pre- soaked
peas in the remaining two paper cups/coconut
shells. Wet the soil by sprinkling little water.
The soil needs to be moistened everyday for about
7-10 days. Observe the pattern of germination for
both bean seeds and the pea seeds
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KIDNEY BEANS Epigeal germination
In kidney beans the cotyledons come above the
soil surface into air and light, due to rapid
growth and elongation of the hypocotyl (hypocotyl
is the stem below the cotyledons). They are green
and make food to be used by stem during growth.
Thus, the cotyledons function as leaves until the
true leaves emerge. These finally dry off and
seedlings become independent. This type of
germination is termed as epigeal (epi above)
germination.
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PEA Hypogeal germination
In case of pea, the cotyledons remain in the
soil. Here the epicotyl (stem above the
cotyledons) elongates and raises the plumule out
of the soil upwards. Cotyledons do not turn green
instead stay below ground where eventually they
are used up. This type of germination is termed
as hypogeal (hypo below) germination.