锥栗开花授粉生物学特性

摘要

A field investigation,and erperiments of pollen germination in vitro,paraffin sectioning and artificial pollination were conducted to study flowering dynamics, pollen viability, stigma receptivity, characteristics of wind pollination and pollen germination of Castanea henry. The results showed that the differentiation time of female flowers in C. henryi was about 40 days,and the differentiation time of a single flower was about 22 days. The stigma receptivity duration was 7 days. The male inflorescence bloomed from April to May,and spanned about 23 - 26 days. The life span of individual male inflorescence was approximately 10 - 12 days. Within 6 days after flowering,the inflorescence maintained the highest pollen viability. Anemophily was the main pollination process of C. henryi,and wind speed and direction were the main meteorological factors affecting the pollination. With emasculation bagging,and without artificial pollination,C. henryi had not fruit. This result indicated that C. henryi did not occur apomixis. The artificial pollination experiment showed that outcrossing could significantly increase the fruiting rate of C. henryi,thus the pollination tree should be configured in the field.%通过田间调查、花粉离体萌发、石蜡切片和人工授粉等试验手段对锥栗的开花动态、花粉活力、柱头可授性、风媒传粉特性和授粉特性等进行研究。结果表明：锥栗雌花群体分化时间约40天，单花分化时间约22天，柱头可授性持续期为7天；雄花序4—5月开花，群体花期23～26天，群体盛花期13～15天，单花序花期10～12天，开花后6天内花粉保持较高活力。风媒传粉是锥栗传粉的主要途径，风速和风向是影响锥栗传粉的主要气象因素，顺风方向上花粉的传播距离及花粉通量显著高于其他3个方向。锥栗在去雄套袋且不进行人工授粉的处理下未坐果，表明锥栗不存在无融合生殖；异交授粉坐果率均显著高于自交，表明异交能显著提高锥栗坐果率，生产上需配置授粉树。