白桦四倍体半同胞家系生长和材性性状的变异及选择

Variation and Selection of Growth and Wood Traits in a Tetraploid Half-Sib Family of Betula platyphylla

为选出白桦(Betula platyphylla Suk.)优异四倍体母本及单株,调查了10年生四倍体半同胞家系子代试验林各家系生长(树高、胸径、材积)、材性(密度、纤维素质量分数、半纤维素质量分数、木质素质量分数、纤维长、纤维宽、纤维长宽比)、通直度、保存率等性状,并进行家系间性状方差分析及多重比较,估算遗传力及遗传增益。依据最优线性无偏估计法(BLUP法),利用DPS软件预测家系的育种值,并结合隶属函数法综合各性状育种值选择优良家系及亲本。通过简单选择指数法,在优良家系内选择优良单株。结果表明:除半纤维素质量分数外,白桦家系间的性状差异均达到显著或极显著水平,胸径及材积性状的表型、遗传变异系数均较大,其家系遗传力也在45%以上。综合各性状育种值选出7个优良家系及母树,其材积遗传增益为5.39%~17.06%,平均增益为10.26%。在优良家系内选出28株优良单株,其平均材积较二倍体(对照)提高137.21%,材积平均遗传增益为27.53%。

To select superior tetraploid maternal parents and individuals of Betula platyphylla,a 10-year progeny test of tetraploid half-sib families was conducted.Growth traits(tree height,diameter at breast height,volume),wood properties(density,cellulose content,hemicellulose content,lignin content,fiber length,fiber width,fiber length-to-width ratio),stem straightness,and preservation rate were investigated.Between-family trait variance analysis and multiple comparisons were performed,estimating genetic parameters such as heritability and genetic gain.Using Best Linear Unbiased Prediction(BLUP)method in DPS software,breeding values of families were predicted,and the breeding value of each trait was combined with the membership function method to select the excellent family and parents.Within superior families,elite individuals were chosen using a simple selection index method.The results showed that,except for hemicellulose content,there were significant or highly significant differences in traits among B.platyphylla families,with substantial phenotypic and genetic variation coefficients observed for traits such as diameter at breast height and volume.Genetic heritability among families exceeded 45%.Seven superior families and maternal trees were selected based on comprehensive breeding values across traits,with genetic gains in volume ranging from 5.39%to 17.06%and averaging 10.26%.Within superior families,28 elite individuals were identified,showing an average volume increase of 137.21%compared to diploid(controls),with an average genetic gain in volume of 27.53%.