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Weedy Life Cycles
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Reproduction
Reproduction in annual weeds is an important transitional phase in the plant's
life cycle. Simultaneously the parent plant is growing vegetatively, and
reproducing its offspring seed.
As such, two generations are present together on the same plant at the same
time. As such two genomes are active in the plant (three in most grasses
with endosperm tissue in the seed). The process of seed development involves
the development of parental tissues (often the seed coat, hull or protective
envelopes) as well as the development of the new seed, the fertilized zygote
(embryogenesis). In grassy weeds like the foxtails (as well as crops such
as maize), the endosperm of the new zygote is also developing with its separate
genome (3N).
The development of all these tissues on the parent plant have profound implications
for what happens subsequent to leaving the parent: dormancy and survival
in the soil seed bank.
