马尾松二代育种群体生长和开花结实性状

对马尾松二代核心育种群体内亲本无性系的树高、胸径等生长性状及开花量、结实量等生殖性状进行了全面调查和分析。51个马尾松二代亲本无性系7年生时平均树高、胸径和材积分别为5.53 m、9.05 cm和0.021 m3,各生长性状在无性系之间的差异显著,各性状的无性系重复力较高。对进入开花结实盛期的39个无性系调查发现,开花量、结实量等生殖性状在不同亲本无性系之间的变异程度比生长性状的高。基于主要生长性状、生殖性状,将39个亲本无性系聚在4个类群内,不同类群存在显著性状差异:类群1生长性状总体较优,雌球花、球果量也较多;类群2生长性状总体较差,开花、球果量也较少;类群3生长性状较优、雄球花数量较多,但雌球花、球果数量较少;类群4生长性状总体较差,但雌球花、球果数多。无性系的雌球花、球果数与生长量呈弱度负相关,因而在选择杂交亲本或种子园建园亲本时,有必要在开展亲本配合力测评的同时,开展亲本的多性状选择,选出28个生长、生殖性状较为均衡(生长量、开花结实量均在中等或中等以上)的无性系,其单株雄球花数、球果数和单株材积分别比参试群体均值高18.2%,8.0%和9.6%。可将这些无性系作为候选优良亲本,结合亲本配合力的测评,从中选择优良的杂交亲本及二代种子园的建园材料。

Characterization of growth and reproductive traits of second-generation parental clones of Pinus massoniana

Major growth traits including height and DBH,and reproductive traits including number of male cones,female cones were investigated to provide insight into controlled pollination and management of seed orchard.The averaged height,DBH and volume of tested clones was 5.53 m,9.05 cm and 0.021 m3,respectively.Significant differences in traits among clones and high clonal repeatability were detected.The degree of variation was higher for reproductive traits such as cones number than that for growth traits such as height and DBH.Based on major growth traits and reproductive traits,the 39 tested clones were clustered into 4 groups,which exhibited large degree of variation in traits.Group 1 exhibited superior growth traits and large amount of female cones and young cones,whereas group 2 exhibited poor growth traits and less cones number.In Group 3,the growth traits and male cones were abundant,but the female cones were poor.Group 4 exhibited poor growth traits but large amount of female cones and young cones.There was a weak and negative correlation between growth traits and female cones number,implied that multiple traits selection would be necessary in the selection of breeding parents and seed orchard parents.From 39 tested clones,28 superior clones were selected,with the average male cone number,young cone number and volume being 18.2 %,8.0 % and 9.6 % higher than the average value for the whole tested parents.The selected clones could be used for controlled pollination and seed orchard parents.