关苍术花部综合特征与繁育系统的研究

Floral syndrome and breeding system of Atractylodes japonica

关键词:  关苍术  开花动态  花粉活力  柱头可授性  繁育系统

Key words:  Atractylodes japonica  flowering dynamics  pollen viability  stigma receptivity  breeding system

摘要:

采用定点观察,运用杂交指数估算、花粉/胚珠比(P/O)测定、套袋授粉等方法,对关苍术的花部综合特征及繁育系统进行研究。结果表明:种群花期为7月下旬至9月初,单花序花期为12～17 d,小花日开放高峰期为早上7:00～8:00; 花粉活力最高(90%以上)在开花后2 h以内,而此时其柱头尚无可授性,柱头在花开48～72 h以内具有较强可授性; 花粉/胚珠比为6 690,杂交指数为5,繁育系统为专性异交,优势访花者为蜂类和蝇类; 套袋和授粉实验结果表明关苍术不存在无融合生殖现象,自交和同株异花结实率很低,其繁育系统以异交为主。通过关苍术花部综合特征和繁育系统的研究,进一步了解其生物学特性,为关苍术资源保护和人工培育提供了理论基础。

Abstract:

The study on floral syndrome and breeding system of Atractylodes japonica was carried out with the method of fixed-point observation,pollen-ovule ratio(P/O),out-crossing index,bagging pollination, in order to provide the theoretical basis for its resource protection and artificial cultivation. The results showed that flowering period of populations was from late July to early September,the life span of individual inflorescence was 12-17 d,and the peak period of daily flowering for floret was at 7:00-8:00 a.m. Pollen vitality was the highest(above 90%)within 2 h,while stigma was no receptivity and its receptivity was the highest after flowering 48-72 h. The P/O ratio was 6 690,hybrid index was 5,breeding system was xenogamy,and the main floral visitors were bees and flies. There was no apomixes based on bagging and pollination studies,inbred and geitonogamous seed setting rate was low. So,the outcrossing was the major breeding system of A. japonica.