元江干热河谷麻疯树开花结实生物学特性

Biological Characteristics of Flowering and Fruiting of Jatropha curcas in Yuanjiang Savanna Valley

在野外定位观测麻疯树单花、单花序、单株花朵的开放动态,利用去雄、套袋、人工授粉对麻疯树结实生物学进行了观察与调查。结果表明：①麻疯树雄花单花期常2d,雌花单花期5-8d。每花序具有雌花0-17朵,雄花49-238朵。花序花期13-19d,常常第1、2天先开雄花,尽管雌花数目较少,但开放速率较快,集中在第3-5天开放。同一植株1a最多开4次花。②果实从授粉至果黄,大致需要50d,果实生长发育曲线呈S型,果实与种子的纵横径的增长速度可分3个时期：生长缓慢期,为授粉后0-15d;快速生长期,为授粉后15-27d;生长缓慢期,为授粉后27-48d。后期历时21d,果实纵横径增长缓慢,但种子质量增加较快,主要是种仁发育消耗营养较多。每果枝具果实1-17个,以1-8个居多,单果枝的果实发育进度与果实数量相关,果数越多,差异越大,反之越小。

A field observations was made on the flowering process of single flower, single inflorescence, individual flower, and the fruiting characteristics of Jatropha curcas L. in Yuanjiang County, Yunnan Province by means of castration, bagging and artificial pollination. Results show that the male flowers last for 2 days, and female flower for 5 to 8 days. Numerically, 0 - 17 female flowers and 49 -238 male flowers are produced per inflorescence. The flowering of each inflorescence lasts 13 to 19 days. Normally, a few male flowers open in the first two days, and then followed by the quick opening of the female flowers from the 3rd to 5th days. A plant can at most bloom four times per year. It needs approximately 50 days for female flower to become ripened fruit after being pollinated. The growing trend of fruit shows S-shaped curve. The fruit growth phase can be divided into three stages in accordance with its growth rate of longitudinal diameter and transverse diameter. The fruit grows slower from 0 to 15 th days after being pollinated, then apparently faster from 15 th to 27 th days, and later slows down again from 27 th to 48 th days. At the last stage, seed weight keeps growing fast mainly because of the great consumption of the nucleolus growth. Each fruit shoot produces 1 - 17 fruits, and 1 - 8 fruits are common. The difference of development process of the fruits per fruit shoot is positively related to its fruit number.