STUDY ON THE INHIBITORY EFFECT OF LONGDAY TREATMENT ON PHARBITIS NIL Ⅱ.THE RELATION BETWEEN DIFFERENT DARK LENGTH PHOTOPERIODS AND FLOWER BUD DIFFERENTIATION AND GENE EXPRESSION IN THE COTYLEDONS

The growth of Pharbitis nil was promoted and its flowering was inhibitedwhen the dark length of single photoperiod was less than₁₂ h.The results of 2-SDS-PAGE indicated that two kinds of proteins (pI4.1, MW16.5 kD; PI4.2, MW16.5 kD)existed in cotyledons.These proteins were disappeared in the cotyledon treated with induced photoperiod when the light length was over 12 h.Poly(A⁺)mRNA in the cotyledons with continuous light treatment (l CL) whose protein weight in vitro translationwas 17.4 kD was not discovered in the one treated with induced photoperiod (lSD).These changes in the Pharbitis nil cotyledons might be related to inhibiting the flowerbud differentiation.