Aba in Photoperiodic inducting of pharbitis nil

摘要

The endogenous content of ABA in the cotyledons of Pharbitis nil is high during the light phase before an inductive 16-h-long dark period. During the night, however, at the beginning, the level of ABA is relatively low with the tenden- cy to increase during the second half of an inductive dark period. The dual effect of exogenous ABA on the pharbitis nil flowering has been observed. ABA applied to the cotyledons on subthreshold photoperiod (12-h-long night) stimula- tes flower bud formation.