降香黄檀生长性状家系间变异与优良家系初选

【目的】评价目前收集的濒危树种降香黄檀种质资源,并选择生长性状优良的家系,为早期降香黄檀良种壮苗生产提供参考。【方法】分别对广东省阳江市百盛园基地与开平市镇海林场的两个8年生降香黄檀子代测定林进行调查分析,在基于生长性状统计遗传学评价的基础上进行早期优良家系的选择。【结果】8年生的降香黄檀林分生长良好,平均树高、胸径、单株立木材积分别为4.30 m、6.31 cm、0.006 1 m³(百盛园)和4.97 m、6.07 cm、0.007 9 m³(镇海),表型变异系数分别为18.37%、34.39%和63.93%(百盛园)以及18.31%、32.61%和60.75%(镇海)。降香黄檀不同生长性状的单株遗传力和家系遗传力分别为0.22～0.41和0.34～0.54。在两个试验点上,不同生长性状之间存在高度的遗传正相关。两个试验点之间存在显著的环境与基因型互作,B型相关系数分别为0.61(树高)、0.53(胸径)和0.51(材积)。从参试的两个试验林共有的45个家系中选择出10个速生优良家系,其8年生时平均树高、胸径、单株立木材积分别为5.06 m、7.31 cm、0.009 2 m³,分别较群体均值大9.28%、18.28%、33.33%,遗传增益分别为3.37%、6.24%和12.86%。从优良家系中选出的12株优良单株,其树高、胸径、材积性状比家系平均值分别增加了53.04%、73.42%、232.78%,遗传增益分别为15.57%、24.60%和64.07%。【结论】降香黄檀的种质资源中存在丰富的家系间以及家系内个体间的遗传变异,可为降香黄檀遗传改良提供丰富的材料。

Growth traits variation among families and preliminary selection of superior families in Dalbergia odorifera T. Chen

Abstract: 【Objective】The study aimed to assess germplasm of the threatened species Dalbergia odorifera, select families with superior growth traits, and provide a reference for early seedling selection. 【Method】 We investigated and analyzed growth traits(height, diameter at breast height(DBH)and stem volume)in two eight-year progeny tests conducted in Baishengyuan in Yangjiang City and in Zhenhai Forest Farm in Kaiping City, Guangdong Province, and selected superior families based on a statistical genetic analysis of growth traits. 【Result】At eight years, tree height, DBH and stem volume in Baishengyuan were 4.30 m, 6.31 cm, and 0.006 1 m³, respectively, and in Zhenhai they were 4.97 m, 6.07 cm, and 0.007 9 m³, respectively. In Baishengyuan, the phenotypic coefficients of variation in height, DBH and stem volume were 18.37%, 34.39% and 63.93%, respectively, and in Zhenhai they were 18.31%, 32.61% and 60.75%, respectively. Moreover, the individual heritabilities of these traits were 0.22-0.41, and family heritabilities were 0.34-0.54. High genetic correlation coefficients were observed among three growth traits at two sites, with correlation coefficients of approximately 0.9. Significant interactions between genotype and environment were observed for three growth traits. The Type B genetic correlation coefficients were 0.61, 0.53 and 0.51 for height, DBH and tree volume, respectively. We selected 10 families from 45 common families at two sites. At eight years old, the means of height, DBH and stem volume for the selected families were 5.06 m, 7.31 cm and 0.009 2 m³, respectively, which represented an increase above population means by 9.28%, 18.28% and 33.33%, and genetic gains of 3.37%, 6.24% and 12.86%, in each case for height, DBH and stem volume, respectively. Twelve plus trees were then selected from superior families, and showed increased values for average height(53.04%), DBH(73.42%)and tree volume(232.78%). The genetic gains from these twelve plus trees showed increases of 15.57%, 24.60% and 64.07% for height, DBH and tree volume, respectively. 【Conclusion】There were high genetic variations within and among germplasm families of D. odorifera, which provided abundant genetic resources for improvement of the species.