主伐龄期马尾松半同胞子代测定林的变异分析及选择

为了评价和筛选优良马尾松种质资源,对3块已达主伐年龄(27、28、29 a)的马尾松半同胞子代测定林生长及形质性状进行分析和遗传评估。结果表明:各子代测定林生长和形质性状在家系间差异均达显著或极显著水平,家系的树高、胸径、材积、冠幅、枝下高受中度或中度以上遗传控制,具有很强的家系及家系内单株选择潜力; 遗传和表型变异系数以材积最大,胸径居中,树高较小。性状间表型和遗传相关分析表明,树高、胸径、材积之间呈强度遗传和表型正相关关系,冠幅、枝下高与各生长性状间呈中等偏上的正相关。利用多性状综合选择指数法评选出21个马尾松优良家系,其平均树高、胸径和材积分别为14.05 m、17.07 cm和0.157 6 m³,平均遗传增益分别为7.65%、12.33%和39.21%。利用家系-单株联合选择法评选出54个优良单株,其平均树高、胸径和材积分别达到15.53 m、24.98 cm和0.341 4 m³,平均遗传增益为13.61%、44.95%和164.98%。试验结果可为西南地区马尾松种子园定向培育供应良种,也可用于选择高世代种子园的建园材料。

Variation analysis and selection on half-sib progeny tested forests of Pinus massoniana at the ages of final cutting

In order to evaluate and select superior germplasm of Pinus massoniana in Sichuan Province, the analysis and genetic evaluation of growth traits(tree height, DBH and stem volume)and stem-form qualities(crown width and under-branch height)were conducted on 3 groups of half-sib progeny tested forests of P. massoniana at the age of 27,28 and 29 years, respectively. The results showed that significant differences were available in growth traits and stem-form qualities among different families. The average tree height, DBH, stem volume, crown width and under-branch height of families were controlled by genetics at medium level or above, which revealed high selection potential among or within families. Stem volume presented large genetic variation among families, followed by DBH and tree height. Strongly positive phenotypic and genetic correlations existed among tree height, DBH and stem volume. Superior middling correlations were observed in crown width and under-branch height with growth traits. Twenty-one superior families were selected by the Smith-Hazel comprehensive index method.For the twenty-one selected families, the average height, DBH and stem volume were 14.05 m, 17.07 cm and 0.157 6 m³, the average genetic gains were 7.65%, 12.33% and 39.21%. Fifty-four superior individuals were selected by the families-individuals comprehensive method, their average height, DBH and stem volume were 15.53 m, 24.98 cm and 0.341 4 m³, the average genetic gains were 13.61%, 44.95% and 164.98%. The selected superior families and individuals can provide improved seeds for the oriented cultivation of P. massoniana in southwest China, or selected materials for advanced generation orchard.