木瓜榕的性表达和繁殖特点

The Sex Express and Reproductive Characters of Ficus auriculata

木瓜榕雌雄异株,种群内一年四季均挂有果实,果量雌多雄少,其中雌树有2次显著的挂果高峰,占了全年挂果量的80%;雄树挂果多集中在10月至下一年的3月份。木瓜榕隐头花果发育进程中,在间花期雌雄果明显分异,雄果发育期长,74%的隐头果能正常成熟;雌果完成生活周期所需时间短,发育中落果率较高,仅22%的隐头果能成功生产种子。木瓜榕隐头果还受5种非传粉小蜂的作用,它们寄生于传粉小蜂或者与之竞争资源,进而影响到寄主木瓜榕的传粉授精和种子生产。

s: Ficus auriculata is a gynodioecious plant.Its pollinator is Ceratosolen emarginatus ,it is highly co-evolved mutualists that depended completely on each other for reproduction. Hence, their structures showed adaptive change. The female flower of Ficus auriculata varied markedly in style length. In the female inflorescence, the style of female flower was long and had some bristles; Stigma was funnelform and possessed short hairs. The structures of long-styled female flowers could prevent oviposition and be beneficial for sticking pollen. Short-styled female flowers developed in the male inflorescences, its style was smooth and suitable for laying eggs. The population of Ficus auriculata had inflorescences around the year, there were 2 peaks in production of female trees, the fruit-bearing ratio was 80%. Most male trees bore fruits from October to March of next year, the fruit-bearing ratio attained 90%. Male inflorescences mainly provide places for pollinating wasps to survive the winter, and producing enough pollination wasps to following fruit-bearing peak of female trees. In the population of Ficus auriculata , diameter of male inflorescence was larger and its developing time was longer than that of female inflorescence, which it costed 125 days to complete whole developmental period, and 78% of male inflorescences could normally be mature. However, female inflorescences only costed 80 days from pre-female to mature phases. 22% of female inflorescences could successfully produce seed because inflorescences were eaten by insects or affected by other factors. Moreover, five species of non-pollination also lived in inflorescences, they laid eggs outside fig to compete ovaries with pollinators, or parasitized pollinators.In result, the population of Ceratosolen emarginatus was restrained, and further influenced the pollination and seed production of Ficus auriculata .