黄瓜花性别分化与内源多胺的关系

研究了黄瓜雌、雄花几个主要发育时期和性别逆转过程中内源多胺的变化。结果表明 ,雄花在不同发育时期 ,内源腐胺含量均高于雌花 ,腐胺含量的显著升高伴随着花粉粒的形成 ,高腐胺含量是雄花发育的特征。雌花在大孢子母细胞时期以后直到雌花发育成熟 ,其内源尸胺含量均高于雄花 ,高尸胺含量可能有利于雌花的发育。高水平的内源多胺、精胺和亚精胺可能有利于雌花大孢子母细胞的形成。亚精胺和腐胺含量随着大小孢子四分体形成和大孢子核的连续分裂而分别表现下降和上升。雌性系黄瓜经硝酸银诱导雄花处理后 ,茎尖内源亚精胺含量下降 ,腐胺含量上升 ,从而诱导雄花形成 ;雄性系黄瓜经乙烯利诱导雌花处理后 ,茎尖内源亚精胺含量上升 ,腐胺含量下降 ,从而诱导雌花形成

Relationship Between Floral Sex Differentiation and Endogenous Polyamines in Cuc umber (Cucumis sativus L.)

Changes in the endogenous polyamine(PAs) contents during floral sex differentiation and sex reversal were studied in flowers of cucumber. The results showed that endogenous putrescine(Put) content was higher in male flower than in the female during floral sex differentiation. Remarkable increase in put content was accompanied with pollen grain formation and development. Endogenous cadavarine(Cad) content in female flower from megaspore mother cell stage to female flower maturation was higher than those in male flowers from microspore mother cell stage to maturation. High level of endogenous Cad content was favorable to female flower development. While high level of endogenous PAs, spermine(Spm) and spermidine(Spd) contents were favorable to megaspore mother cell development of female flower, it seems that Put and Spd contents increased and decreased,respectively,as the formation of both microspore and megaspore tetrad and continuous division of megaspore nucleus(Fig.1). Endogenous Spd and Put contents in the apex tissue of gynoecious cucumber decreased and increased, respectively, after application of silver nitrate, which caused male differentiation(Fig.2). They, however, increased and decreased,respectively, in the apex tissue of androecious cucumber after application of ethrel, which caused female differentiation(Fig.3).