| There are three breeds of hispida(Benincasa hispsda Cogn.chieh-qua How.) to be the material for our experiment,including:"R89-3-7-5","Qi Xing"and"Jiang Xin".We analyse the characteristic and influence factors on sex differentiation of hispida.The main results were as follows:1.There are three periods in the growth of hispida's flower,including:uni- sexual,then hermaphrodism,finally is maleness or femaleness。No significant morphological difference existed in female and male flowers at stages earlier than hermaphrodism stage。We can control the sextual differentiation with the expression gene of sex and reverse the expression process。When the size of male and female flowers is 0.90±0.23mm﹑1.12±0.21mm in hispida,the hispida's flowers will turn from unisexualy into male or female.But commonly,once the differentiation developed into the monosexual stage,the differentiation process will comparatively level off and will be a monosexual flower。The pivotal process is the result of electing ungrowth。We summarize this process as following:The process of sex differentiation is not consistent.The male upgrowth is fast than female.We can summarize the result from the structure:The anlage of male is not upgrowth in female and degenerate in the megaspore mother cell,but the anlage of female is upgrowth in male The difference expression was the reason for this phenomena。2.The plant height﹑stem diameter﹑lenghth of node decreased gradually as the increasing of GA3's concentration。The plant height﹑lenghth of node﹑stem diameter were 41.4%,62.4%,63.9% of CK;The node position of the first male flower was increasing at beginning then decreasing of CK,The node position of the first male flower was smaller than 5.0, It was decreasing of CK when treated with 200mg/L,240mg/L GA3。The node position of the first female flower was increasing gradually as the increasing of GA3's concentration,The node position of the first male flower was increasing 6.4 and 7.0 node than CK as the 200mg/L,240mg/L GA3 concentration。In this experimental scope ,The result was the best as treated by 200mg/L GA3。Ethylene is the good reagent for inducing male,The plant height﹑stem diameter﹑lenghth of node decreased gradually as the increasing of ethylene concentration。The hispida will appear male and decrease the noda of the first male as the 40mg/L ethylene concentration;The hispida will not appear male in the o5 node as the 480mg/L ethylene concentration。The node position of the first male flower decreased 2.6 than CK when treated by 40mg/L ethylene concentration。The hispida will appear male and not restrain the growth as by 40mg/L ethylene concentration。3.Hispida is the day-neutral plant,but the short-day can incease the amount of female,especially in the seedling.But the severity short-day can effect the growth development of hispida.The female rate inceased 9% than CK,The chla.﹑chlb.﹑the total of chl.﹑car. Of two breeds were decreased than CK as the concentration。The POD of hispida decreased as the photoperiod increasing。The POD of hispida was the lowest as treated by photoperiod of 17h,it were 1.787g-1min-1﹑1.438 g-1min-1and were 74.9%﹑64.7% of CK.The female rate idirected ratio with POD.The MDA﹑ ABA and the soluble Pr. were conjunction.Breeds is indiscrimination on photoperiod and temperature treating。4.The appropriate NH4+-N can promote the absorbability for NO3--N in hispida,the absorbtivility of Ca﹑Fe is inceasing。the appropriate chromajof NH4+-N is 25%.Yang Zhimin(1989)consided that increasing the NH4+-N chroma can add the absorb of cucumber,this experiment testified the relation between the NH4+-N and NO3--N.With the treated of 100% NO3--N,the stem and leaves were increasing .The increasing of GA3 can promote the male of hispida.It's consistent with Heslop-Harrison(1972).It's harmful for foot of hispida,75% NH4+-N can promote caducity of leaves and ABA chroma was 400ng/gFM,the chroma of MDA was 1.234μmol/g.
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