Distribution of Pistillate Flowers and Disciplines of Fruit-set Success in Rubber Tree (Hevea brasiliensis Muell. Arg.)

The disciplines of pistillate flower distribution and fruit-set location of six cultivars were investigated in Hevea brasiliensis. Results showed that there were significant differences in the number of pistillate flowers, locations of pistillate flowers on panicles and number of panicles in fruit-set branches among different cultivars. Similar to the distribution of fruits on panicles, pistillate flowers were distributed on the top or lower positions of panicles. Pistillate flowers that produced fruits grew mainly on the lower positions of the fruit-set branches. The pro-bability of fruit-set decreased with distance between panicles and trunk increasing. Thus, based on the disciplines of pistillate flower distribution, fruit-set panicles and fruit, the efficiency of crossbreeding could be improved by pollinating panicles on the fruit-set branches with higher fruit-set rates and synchronously thinning pistillate flowers with lower fruit-set rates.