马尾松无性系种子园结实初期异交水平分析

Analysis on Outcrossing Rate in a Masson Pine Clonal Seed Orchard during Early Phase of Seed Production

利用 1993年和 1994年测定数据 ,采用球果饱满种子百分率方法估算马尾松无性系种子园异交率。研究发现 8～ 9年生马尾松无性系种子园在结实初期自交率较高 ,异交水平较低。利用不同杂交组合估算的各亲本无性系在自由授粉情况下的异交率差异较大 ,两年中分别为 4 4 .7%～98.1%和 30 .8%～ 96 .8% ,平均为 73.5% (标准误差 SE=17.3% )和 6 9.2 % (标准误差 SE=2 1.3% )。异交率在无性系间变异较小 ,在无性系内不同组合间变异较大 ,前者变异系数仅为后者的35.3%～ 53.0 %。相同双亲组合的异交率在相邻两年度间差异不显著 ,并存在着显著的正相关。同时 ,还发现异交率与座果率有显著的线性正相关关系。

Proportions of full seeds in outcrossed cones,self pollinated cones,and open pollinated cones in 1993 and 1994 was used to estimate outcrossing rate of a masson pine clonal seed orchard.It was found that there existed higher selfing rate in the masson pine clonal seed orchard at age 8 or 9.The great differences were found between clones from various parents for outcrossing rates under open pollination,which ranged from 44.7% to 98.1% (av.73.5%±17.3%) in 1993,and from 30.8% to 96.8% (av.69.2%±21.3%) in 1994 respectively.The outcrossing rates were larger among combinations within clones than among clones.The coefficient of variability of the former was 35.3% to 53.0% of the latter.No significant differences were observed for outcrossing rates of the same combinations between two years.Meanwhile,the crossing rates were found to be significantly and positively related to the fertilized cone rates.Finally,main factors affecting crossing rate was discussed.