一.引言蔷薇科果树种类繁多,分布地区也广,在经济果树中佔有极重要的地位;但因果树本身以及环境关系,常常不能得到质量都好的产品,以致果農们在经济上遭受很大的损失,这是我们科学工作者应该从各方面去进行研究的问题。花粉活力的强弱,对於果树生产起着很大的作用。自从伟大的自然改造者米丘林采用混合授粉,增加果树结实率的方法以来,对於花粉活力的研究,更增加了它在实践上的意义。因为如要果树结实良好,必须具有活力较强的花粉;不同花期或不同栽培区域的品种进行杂交, I. Introduction Rosaceae fruit trees are numerous and widely distributed, occupying a very important position in economic fruit trees. However, fruit trees themselves and their environmental relations often can not obtain products of good quality, so that the fruit growers are greatly financially exposed This is a question that our scientists should study from all aspects. The strength of pollen vitality, for the production of fruit trees play a big role. The study of pollen viability has increased its practical significance since the method of mixed pollination and increased seed setting of Michurin, a great natural reformer. Because if you want to fruit trees well, you must have a strong vitality of pollen; flowers in different flowering periods or different areas of hybridization,