油松种子园自由授粉与控制授粉种子父本分析

利用“微卫星”标记对油松(Pinus tabulaeformis)种子园控制授粉和自由授粉的子代进行了父本分析, 探讨自由授粉状态下种子园子代遗传组成与花粉传播的关系, 以及人工控制授粉状态下花粉形态等指标与子代遗传组成的相关性。其中,利用SSR对281粒油松种子进行父本分析, 在80%的置信水平下确定了其中126粒种子的花粉来源; 对2株母树自由授粉种子的父本分析表明, 种子园内花粉传播距离最大为85 m, 有效距离在30 m以内; 对11#和24＃母树分别用21个无性系的等体积混合花粉进行控制授粉发现, 子代由少数无性系的花粉受精产生, 其中 50＃、7＃、25＃、33#无性系对2株母树子代的花粉贡献率分别达到50.62%和61.54%; 花粉粒大小、花粉等体积重和花粉活力与选择性受精相关不显著, 而花粉活力偏低的无性系也有授粉成功的可能性。

PATERNITY ANALYSIS OF OPEN- AND CONTROL-POLLINATED SEEDS COLLECTED FROM A SEED ORCHARD OF PINUS TABULAEFORMIS

Aims Our objective was to develop theory for design and reestablishment of high-generation seed orchard by discussing the relationships between pollen dispersal distances and genetic composition of seed orchard progeny under open- and control-pollinated situations. Methods Open- and control-pollinated seeds were collected from two maternal trees. Microsatellites markers (SSRs) were used in paternity analysis. A total of 281 progenies were analyzed, of which the paternity could be accurately identified for just 126. Paternity inference was conducted using CERVUS software. Important findings Analysis of open-pollinated seeds of two clones, Nos.11 and 24, showed the effective dispersal distance of pollen is within 30 m and the longest dispersal distance is 85 m. 11.1%–12.8% of pollen-father comes within a radius of 10 m from the seed tree, 37.0%–40.4% within 10–20 m and 17.2%–22.2% within a radius of 20-30 m. In order to discover the key factor to selection fertilization, the paternity analysis of control-pollinated seeds for two clones, Nos.11 and 24, was estimated too. Four clones. Nos. 50, 7, 25 and 33, applied 50.62% and 61.54% pollen to control-pollinated seeds collected from two mother trees, but the reason is not yet clear. We analyzed the influence of pollen size, weight and vigor on selection fertilization, but no significant correlation was found. We suggested detailed study of influence of pollen-tube growth rate on selection fertilization.