5年生南方红豆杉生长和分枝性状家系变异与选择

目的]对5年生南方红豆杉优树家系进行全林测定,以揭示其生长和分枝性状家系遗传变异规律,为不同区域和立地筛选出速生优质和遗传稳定的家系。方法]利用2014年设置在浙江淳安、江西分宜和福建明溪3个地点的5年生南方红豆杉优树家系测定林,分析其家系遗传变异规律及家系与地点的互作,初选出一批速生优质家系。浙江淳安、江西分宜和福建明溪3个地点参试的家系数分别为55、39和32个,浙江淳安和江西分宜、浙江淳安和福建明溪及江西分宜和福建明溪的共有家系数分别为38、14和12个,3个试验点的共有家系为11个。结果]5年生南方红豆杉生长和分枝性状在家系间的差异均达到极显著水平,树高和一级分枝数这2个性状的家系X地点互作效应明显,其它性状的家系与立地互作效应则较小。南方红豆杉家系各生长性状间,以及生长性状与一级分枝数和最大分枝粗等均呈极显著的正相关。5年生南方红豆杉家系遗传力估算值总体较高,与家系遗传力比较,其单株遗传力估算值稍低。以树高为选择标准并兼顾分枝性状,在3个试验点共初选出10个优良家系。结论]5年生南方红豆杉家系间,各生长与分枝性状具有丰富的遗传差异,南方红豆杉家系遗传力普遍较高,受较强遗传控制。树高和地径生长突出的家系,分枝多且粗、枝叶茂密、冠幅宽。树高和一级分枝数是两个对立地条件较敏感的性状,其家系X地点互作效应极显著,立地对其影响较大,其中,SY10家系在多个地点皆表现较好且稳定。

Family Variation and Selection of Growth and Branching Traits of 5-Year-old Taxus wallichiana var.mairei

Objective]By testing Taxus wallichiana var.mairei elite families to select the fast-growing and genetically stable families suitable for different regions and sites.Method]5-year-old T.wallichiana var.mairei elite family plantations from different habitats were used to study the genetic variation and the family × site interaction.The experimental forests were established in 2014 at 3 sites(Chun'an of Zhejiang Province,Fenyi of Jiangxi Province and Mingxi of Fujian Province).Among the families used in the test,55 from Chun'an,39 from Fenyi,and 32 from Mingxi.There were 38 families shared by Chun'an and Fenyi,14 families shared by Chun'an and Mingxi,12 families shared by Fenyi and Mingxi.There were 11 families shared by all the three sites.Result]The growth and branching traits of 5-year-old T.wallichiana var.mairei showed extremely significant differences among families.The family x site interaction effect on tree height and primary branch number was obvious.And the effect on other growth traits and branching traits was minor.There was a significant positive correlation among the growth traits and among the growth traits,primary branch number and the biggest branch diameter.Generally,the family heritability of the 5-year-old T.wallichiana var.mairei was higher.Compared with family heritability,the estimated heritability of the individual was lower.Taking the tree height as the selection criterion and considering the branching traits,a total of 10 excellent families was selected from the 3 sites.Conclusion]There exists significant genetic differences in growth and branching traits among the families.The family heritability of 5-year-old T.wallichiana var.mairei is generally higher,and they are controlled by stronger genetics.The thicker and taller the tree,the more branches it has.The traits of tree height and primary branch number are sensitive to site,and the family x site interaction effect is extremely significant,and the site has a greater impact on it.It is found that the family SY10 performs well and is stable in multiple sites.