Abstract:

Figs and their pollinating fig wasps bear the obligate species-specific mutualism. The entering of pollinating Ceratosolen fusciceps would bring two incidents come into truth: egg-laying and pollination. Firstly the C. fusciceps pollinates for the long-styled florets and makes them fertilized, which can complete the normally sexual reproduction of Ficus racemosa. Secondly the entering wasps oviposit in the ovules of short-styled florets that subsequently develop into gall flowers and produce fig wasps, hereby, they finish the mission of propagating off-springs and ensure the persistence of the fig wasp species, meanwhile, function as the media of fig pollinators. Our study was focused on the seasonal change of fruits of F. racemosa at the 2 sites in Xishuangbanna. We carried out two-year long consecutive dissection and observation on them, and collected the data on the quantity of gall flowers, seeds and abortive flowers inside the syconia of male phase, furthermore, compared the ratios of florets between the dry and rainy season two years round. The results were that the ratios of various florets varied in different season. F. racemosa produced the highest crop of seeds in Jan. and Nov. of dry season; next to it was in Sep. and Oct. of the end of rainy season; the lowest one was in Mar. of each year. The parasitic ratios of gall flowers shared no significant difference between the dry and rainy season, while the distinction among months was significantly different, and the highest parasitic ratio was in Jan. of dry season and May of early rainy season, the lowest one was in Mar. The abortive ratio of long- and short-styled female florets was highest when the temperature was lowest (Jan. to Feb.) and when the rainfall was most (Jul. to Aug.); the lowest abortive ratio was during the early phase of rainy (May) and dry season (Nov.). The floret abortion inside the syconium was mainly subject to the climate of low temperature and heavy rainfall. Nonpollinating fig wasps species include gall makers and inquilines; these have a great impact on the propagation of seeds of F. racemosa.

Key words: Ficus racemosa, seed, Ceratosolen fusciceps, pollinating, rainy season, dry season