遮荫对单性花同株植物麻疯树性比与构件大小的影响

光照环境对营养生长存在明显影响已经是不争的事实,但光照影响器官的效应必然会引起生殖性状的反应,尤其是雌性适合度表达。本文利用麻疯树林分乔木林遮光与否的对比,研究遮光对麻疯树构件水平上营养器官与生殖器官的影响,探究光照对雌花数量与性比影响的本质问题。结果如下:(1)倮果桥林下麻疯树雌花数量频度分布偏左,平均为2.716 0/支±3.3052/支,而林外频度分布偏右,平均为5.0417/支±4.4106/支,二者差异极为明显;(2)倮果桥林下性比频度分布偏左,平均为0.0278/支±0.0215/支,而林外麻疯树性比频度分布偏右,平均为0.0378/支±0.0738/支,二者存在显著差异;(3)林下构件直径频度分布偏左,平均为0.8112 cm±0.1973 cm,而林外构件直径为0.9125 cm±0.2809 cm,频度分布偏右,林外与林外构件直径差异极为显著;(4)林下构件长度为8.3255 cm±10.057 cm,频度分布偏左,而林外构件长度为18.548 cm±19.3817 cm,构件枝长在林下与林外存在极显著差异。乔木林遮光使得麻疯树雌花分化数量与性比偏低,频度分布偏左,表明光照降低了麻疯树的雌花分化能力。进一步分析表明,雌花分化能力降低与构件大小减小有关,表明光资源限制通过降低营养器官生长量进而实现对雌花分化的影响与调节。

The Influence of Light Shading on the Sex Ratio and Modular Size of Jatropha curcas, a Monoecious Plant

It was a universal fact that the light obviously affected the vegetative growth,however these effects of influenced organs would inevitably bring about the response of reproductive features,especially to the expression of female fitness.This paper used the light-shading effect of arbor forest with a control to study the light-shading response of reproductive and vegetative organs for modules in Jatropha curcas and discuss the mechanism of light effect on amounts of female flower and sex ratio.The result showed as follows：（1） the amount of female flower was 2.72±3.31 every module with a quasi-left distribution of frequency in the understorey,and 5.04±4.41 every module with a quasi-right distribution in the outstorey,and there was an extreme significant difference between understorey and outstorey;（2） The sex ratio of understorey was a quasi-left distribution with an average of 0.0278±0.0215 every modular,and that of outstorey was a quasi-right distribution with an average of 0.0378±0.0738,and a signifcant difference existed between them;（3） Module diameter of understorey was averagely 0.8112 cm±0.1973 cm with a quasi-left distribution of frequency,and of outstorey was averagely 0.9125 cm±0.2809 cm with a quasi-right distribution,and an extreme significant difference existed between understorey and outstorey;（4） The module length was a quasi-left distribution with an average of 8.3255 cm±10.057 cm in the understorey,and a quasi-right distribution with an average of 18.548 cm±19.3817 cm in the outstorey,and there was a significant difference between understorey and outstorey.In the Jatropha curcas forest,the light-shading effect of arbor forest made the differentiation of female flower and sex ratio lower with a quasi-left distribution,which indicated that light constriction decreased the differentiation capacity of female organ.The furthur ananlysis demonstrated that the decreased capacity of female organ was related to smaller modular size,implying that light limitaton realized the influence and adjustment on or to differentiation of female flowers through decreasing the growth product of vegetative module.