稀有植物小丛红景天花部综合特征与繁育系统

目的研究极小种群野生植物波叶杜鹃(Rhododendron hemsleyanum)的花部特征和繁育系统，为其作为乡土园林树种推广提供遗传育种理论基础。方法对四川峨眉山波叶杜鹃野生居群资源现状进行深入调查，研究其花部形态、花粉—胚珠比、杂交指数和昆虫访花行为等，并结合人工控制授粉试验对其繁育系统展开研究。结果5月中旬为波叶杜鹃的盛花期；其杂交指数为5，花粉—胚珠比为640.93±65.52；自然对照结实率为56.67%，异株异花传粉结实率为86.67%；主要访花者是中华蜜蜂(Apis cerana)和排蜂(A. dorsata)。结论波叶杜鹃的最佳授粉时期为盛花期(开花第3~6天)，其繁育系统是倾向于异交的混合交配系统，自然条件下有效传粉者为中华蜜蜂和排蜂。

Variations in pollinator density and impacts on large cardamom (Amomum subulatum Roxb.) crop yield in Sikkim Himalaya,India

PurposeTo study the floral syndrome and breeding system of Rhododendron hemsleyanum, a plant species with extremely small populations, and to provide a genetic breeding theoretical basis for the promotion of R. hemsleyanum as a native garden tree. MethodsThe status of the R. hemsleyanum wild population in Emei Mountain, Sichuan, were investigated, and its floral syndrome, pollen-ovule ratio, hybridization index and insects’ flower-visiting behavior were studied, as well as its breeding system in combination with artificial controlled pollination tests was researched. ResultsThe blooming period of R. hemsleyanum was mid-May; the hybridization index was five, the pollen-ovule ratio was 640.93±65.52; the fruiting rate of the natural control was 56.67%, and the fruiting rate of heterogeneous pollination was 86.67%; the main flower visitors were Apis cerana and A. dorsata. ConclusionThe best pollination period for R. hemsleyanum is at the peak of flowering (the 3rd-6th day of flowering), its breeding system is a mixed mating system that tends to be heterozygous, and the effective pollinators are A. cerana and A. dorsata.