Effects Of Different Photoperiodic Treatment On Luffa Flower Sexual Differentiation In Seeding Stage

This paper studied the effects of four kinds of photoperiod [day/night:6h/18h,8h/16h,10h/14h and CK(about 14h/10h)]on the two cultivars of Luffa.acutangula Roxb.(Huang-guan No.1 and Xia-si NO.1).The sex differentiation and theoretic yield were measured as well as the correlation physiological indexes during photoperiodic treatments,then the optimum daylength of huang-guan No.1 and Xia-si NO.1 was defined.The conclusion as follows:1,Compared with control,the 1^stfemale flowers were occurred about 10 days earlier,the node order got lower by 10-20 nodes;The 1^stmale flowers were occurred about 6-10 days earlier,the node order got lower by 2-3 nodes.2,Compared with control,the number of female flowers were both increased by the 10h treatments,but reduced by the 6h and 8h treatments in two cultivars.The number of male flowers were reduced in Huang-guan NO.1, but increased in Xia-si NO.1 by shortday treatments.The ratio of female to male flower was increased by the 10h treatments.3,Compared to control,the yield of Huang-guan NO.1 and Xia-si NO.1 was increased 14.84%and 19.49%each by the 10h treatments,reduced 9.63%and 12.05%by the 8h treatments and also reduced 14.10%and 20.38% respectively by the 6h treatments.4,Under different photoperiodic treatments,the trend of change on Free Amino Acids was decreasing in two cultivars luffa in general and there was no significant difference among different photoperiodic treatments.Based in the theory of balancing of endogenous hormone and the endogenous hormone determining,the result showed that:The male flower development was promoted by high contents of GA₃;The female flower development was promoted by high ethylene release rate;Low contents of ZRs and IAA were beneficial to sex differentiation;The contents of ABA which reached peak in prophase,then maintained lower level in anaphase,was advantageous to sex differentiation;The increasing of ABA/GA₃ and GA₃/IAA ratio,an appreciable extent ZRs/IAA ratio(Huang-guan NO.1 between 1.2 to 10.5, Xia-si NO.1 between 0.5 to 1.0)were favor of sex differentiation;High level ratio of ABA/IAA and low level ratio of ZRs/GA₃ and ZRs/ABA were advantageous to flower bud morphogenesis.Comprehensive analysis of effects of different photoperiodic treatments on sexual differentiation and yield showed that 10h treatment was the optimum daylength in two cultivars.