In vitro pollen grain germination and starch content in species with different reproductive cycle. I. Lycopersicum peruvianum Mill.

Lycopersicum peruvianum, which has a long flowering period and several reproductive cycles every year, has mature pollen without starch. During in vitro germination starch is synthesized in June only, when, on the contrary, tubes show a half of the length reached in September. These differences are explained on the basis of environmental factors.