多花野牡丹传粉生物学特性研究

多花野牡丹花期从5月初至6月末,单朵花开放1 d。异型雄蕊,5枚黄色花药位于柱头的上方,5枚紫红色花药位于柱头的下方两侧。花粉为扁球形,极面观为六裂圆形,黄色花药中花粉的三假沟连接到两极,紫红色花药花粉的三假沟未连接到两极。黄色和紫红色花药的花粉活力不同,并随开花进程有下降趋势。该物种存在无融合生殖现象。异花授粉单果饱满种子数显著高于自花授粉,两种传粉方式中,黄色花药中的花粉授粉效果好于紫红色花药。传粉昆虫有圆花熊蜂、红光熊蜂、鞋斑无垫蜂等,9:00~10:30昆虫访花频率最高,11:40以后见不到昆虫访花。杂交指数为4,繁育系统为部分自交亲和,异交,需要传粉者。花粉与胚珠比为601.54,繁育系统为兼性异交。

Characteristics of pollination biology of Melastoma affine

The flowering stage of Melastoma affine extends from the beginning of May to the end of June,and the opening period of single flower lasts one day.With heterostemony,five pieces of yellow anther lie above the stigma,and five pieces of mauve anther dividing into two parts lie below the stigma.The shape of the pollen grains is subspheroidal,and they are 6-lobed circular in polar morphology.3 pseudo-colporates of the pollens with yellow anthers connect the two poles,while the other 3 pseudo-colporates with mauve anthers do not.Different pollen viability exists between the yellow anthers and the mauve ones,and the differences decrease with the development of flowers.The number of seeds in per fruit with cross-pollination is obviously higher than that of the self-pollination.As for the two kinds of pollination,the effect on pollination with yellow anthers is better than that with mauve anthers.The pollination insects include Bombus sapporensis,Bombus ignites,Amegilla calceifera and so on.The frequency of the pollination insects visiting the flowers is highest from 9:30-10:30 a.m.per day,and there are no visitors after 11:40 a.m.The outcrossing index is 4.The breeding system is partially self-compatible,while the outcrossing demands pollinators.The ratio of pollen and ovule is 601.54,and the breeding system belongs to compatible outcrossing.