美洲黑杨无性系生长和材性性状遗传变异与选择

Genetic Variation and Selection of Growth and Wood Properties Traits in Populus deltoides Clones

本研究为了解美洲黑杨无性系生长与木材材性性状遗传变异及相关性,以泗洪县陈圩林场11个美洲黑杨无性系为材料,通过方差分析、遗传参数估算和相关分析等方法,分析杨树无性系生长性状与材性性状的遗传变异规律及性状间相关性,并在此基础上开展杨树优良无性系生长与材性性状的联合选择。结果发现,生长与材性各性状变异在无性系间存在显著或极显著的差异。树高、胸径和材积性状的遗传力分别为0.735、0.760和0.764,遗传变异系数分别为9.14%、15.40%和32.33%,生长性状的变异主要来源于各无性系遗传基础的差异。基本密度、气干密度、抗弯强度、抗压强度和抗弯弹性模量性状的遗传力分别为0.818、0.708、0.635、0.238和0.320,遗传变异系数分别为6.15%、5.67%、6.30%、3.96%和4.82%,表明前3个材性性状变异主要来源于无性系遗传差异,后2个性状受环境影响较大。相关分析结果表明,美洲黑杨树高、胸径和材积之间正相关极显著;基本密度、抗弯强度和抗压强度等材性指标之间呈显著或极显著正相关;生长性状与材性性状间的相关性不显著。利用综合指数选择法开展了美洲黑杨11个无性系的生长与材性联合选择,选择出2个速生优质无性系,分别为无性系4-45、4-6,材积生长量增益较高(达19.79%),杨树遗传改良效果较好。这些分析结果为杨树新品种选育提供科学依据。

The purpose of this study was to understand the genetic variation and correlation between growth and wood properties of Populus deltoides clones. Eleven clones of P. deltoides in Chenwei Forest Farm of Sihong County were used as materials. We took the analysis of variance, genetic parameter estimation and correlation analysis to analyse the rule of genetic variation and correlation for the 11 poplar clones. On this basis, we developed the joint selection of poplar excellent clonal growth traits and wood properties. It was found that the genotype had significant or extremely significant differences on the growth and wood property. The broad-sense heritability of tree height, diameter at breast height and volume were 0.735, 0.760 and 0.764, respectively. The genetic variation coefficient for tree height, diameter at breast height and volume were 9.14%, 15.40% and 32.33%, respectively.The variation in growth traits were largely due to the genetic difference between these poplar clones. The broad-sense heritability of these five wood properties characteristics, including basic density, air dry density, bending strength,compressive strength parallel to grain and bend elastic modulus, were 0.818, 0.708, 0.635, 0.238 and 0.320,respectively. The genetic variation coefficient for basic density, air dry density, bending strength, compressive strength parallel to grain and bend elastic modulus were 6.15%, 5.67%, 6.30%, 3.96% and 4.82%, respectively.Showing variation of the first three wood traits were mainly come from the genetic differences among clones, and the last two traits were greatly affected by the environment. The correlation analysis indicated that an extremely significant positive correlation between the three growth traits, including tree height, DBH and volume. The basic density and air dry density was significantly or highly significant and positively correlated with mechanical properties(MOR, compressive strength parallel to grain and MOE). There was no significant correction between the growth traits and the wood characteristics. By multi-traits phenotypic assessment for union selection on the growth traits and wood properties of eleven P. deltoides genotypes, we screened out two excellent clones(4-45,4-6) with speedy growing and high quality. The selection method had achieved relatively high gain in volume yield(19.79%), and exhibited a preferable effect on poplar genetic improvement. These analysis results provided a scientific basis for breeding its new varieties poplar.