杉木无性系种子园花粉数量的研究

本研究为福建省洋口林场1966年的杉木嫁接种子园,包括42个无性系,200株母树,面积0.7公顷,母树平均树高8—9米。 依据母树“雄球花”的数量和生长状况,把种子园的母树区分为三类,即“簇生”、“混生”、“单生”,从各类母树中随机抽取3～4株作为样株,统计每株母树的“雄球花”数量和每个“雄球花”的花粉数量。 研究结果表明,每一个小孢子囊花粉粒的数量是3700粒,每一小孢子叶球含有264个小孢子囊,而一个“雄球花”又含有26个小孢子叶球,再估算出一个“雄球花”产生大约2540×10~4粒花粉。根据杉木种子园中一株母树的“雄球花”数量和一个“雄球花”的花粉粒的数量来估算每株树产生花粉粒的数量。在三种类型的母树中,每株树的花粉平均数量为532×10~8粒,估算这个无性系种子园所生产的花粉数量约91540×10~8粒。

A Study of the Number of Pollen Grains Produced by the Chinese Fir in the Clonal Seed Orchard

The seed orchard covers an area of 0.7 hectare with about 200 trees (42 clones), which were grafted with mature scions in 1966 and now are 8-9 meters high on an average. It is located in Yangkou Forest Farm, Fujian province.According to the numbers of "male cones", the trees in the orchard were divided into three classes, i. e. "single", "disorder" and "cluster". Three or four trees were selected from each class at random, and the numbers of "male cones" on each tree and the numbers of pollen grains per "male cone" were counted separately.The average numbers of pollen grains per microsporangium were 3, 700, and there were 264 microsporangia in each microstrobilus and 26 microstrobiluses in each "male cone". Thus, it was estimated that a "male cone" produced about 2, 540 x 104 pollen grains.According to the numbers of "male cones" per tree in the clonal seed orchard of Chinese fir and the numbers of pollen grains per "male cone" , the numbers of pollen grains produced by each tree could be estimated. The average numbers of pollen grains per tree in each class were 532 x 108. So by estimate there were about 91, 540 x 108 pollen grains in number in this orchard.?122