A CONTRIBUTION TO THE REPRODUCTIVE BIOLOGY OF SINOPODOPHYLLUM HEXANDRUM(ROYLE)YING(BERBERIDACEAE)
Ma Shaobin; Xu Zhengrao and Hu Zhihao (Department of Biology, Yunnan University, Kunming 650091)
The breeding system of Sinopodophyllum hexandrum (Himalayan Mayapple) hasbeen studied in this paper, the results are presented as follow: In order to adapt the environtnent of short growing season, all morphology of the flower of Sinopodophyllumhexandrum has been forrned in the former year of blossoming, but megasporocyte andmicrosporocyte has not processed meiosis. Flower passes frigid winter and early springin form of dormant bud. In next spring, when temperature goes up and arrivals at athresheld temperature(about 7℃), megasporocyte and microsporocyte begains to meiosis, after meiosis, plant brings flower and leaves out of the earth by intercalary growthand in bloom in two or three days. Flower blossomes be fore leaves grow up. The planthas a series morphorlogical and bliological character adapt to self-pollination, but meanwhile it also has many mechnisms concerning with allogamy. The plant often showspolymorphornism in blossoming habits and flower morphorlogy. In natural condition,Himalayan Mayapple mainly processes autogamy, sexual reproduction is good. In averagy, each individual can produce about 60 seeds,maximum is about 180. The time oflife cycle is about 5 or 6 years. In favourable environment, Himalayan Mayapple alsoprocess vegetative propagation with rhizome. Himalayan Mayapple is diploid, 2n=2x=12. There are fewer chismas during meiosis. Over all,Himalayan Mayapple has comperatively larger present fitness and a bit of evolutionary flexibility.