the Ecological role of phytochrome. Germination of seeds in soil

you are: the Ecological role of phytochrome

Because of requirement for Fdk light is necessary for germination for Many seeds: under a layer of earth they remain in rest, but well sprout on its surface. Seeds of usual weed Verbascum braftaria are that, for example. In 1973, in 90 years after trial zakapyvanija, 20% of seeds of this plant were still viable also sprouts on the growth did not differ from control, received of fresh seeds. Though during a long dormant period such seeds continue to breathe that reduces a reserve of nutrients, the expense of the last can be very insignificant if phytochrome is presented by the form of Fk.

For germination light is not necessary to Fresh seeds of many weeds, but the requirement in the light of arises at their premise in soil, especially in the rehumidified. Apparently, these seeds originally contain many Fdk who in the dark turns again in Fk. This reversii does not occur, if seeds are stored in dry air as phytochrome of seeds in these conditions degidratiruetsja, and dry Fk and Fdk are not capable to interconversion. but if soil so damp that phytochrome of seeds partially gidratiruetsja occurs reversija which at stored seeds, probably, serves as the effective mechanism of a survival.