四合木繁殖特性的研究

对四合木（Ｔｅｔｒａｅｎａ ｍｏｎｇｏｌｉｃａ Ｍａｘｉｍ）的系列特性做了综合研究。结果表明，四合具有有性和无性生殖２种形式的繁育系统，以有性生殖占主导地位。该种成熟的花粉及柱头表面均较平滑，开花时花柱伸和苴柱头稍有膨大，但估不发达。子 在部具花盘。子房壁和花盘执行蜜腺功能。开花前，密腺开始发育，花后密腺成熟并有分泌行为。套袋实验发现，四合木传粉方式以异花传粉为主，传粉结束后统计，异花传粉结实率为

Studies on the reproductive characteristics of Tetraena mongolica Maxim

The reproductive characteristics of Tetraena mongolica Maxim were studied comprehensively.The results were presented as follows: Tetraena mongolica Maxim had two forms of reproductive system:sexual and asexual,the former played a leading role.The surfaces of the mature pollon and stigma were relatively smooth.The style extended and the stigma inflated slightly in blossom,but stigmatic papillae were undeveloped.The floral disc was observed at the base of the ovary.The floral disc and the ovary wall functioned as nectaries.Before blossom,the nectaries developed gradually.They matured and secreted after blossom.Bag mark experiment showed that the out crossing was the main form of pollination.Statistics after pollination showed the out crossing rate of fruit setting was 50%,while selfing rate was 15%.The rate of seed setting was measured as 1.9% in natural population.The floral syndromes more adapted to the inter flower pollination by insects,but insects were rarely observed in natural populations.This probably was main cause leading to low rate of fruit setting.Self pollination with certain frequency appeared to make up the lack of out crossing chance.This is also a kind of evolution expression.The restrict of pollination is probably one of the cause of high abortion rate.