滇南亚高山巨桉种源/家系变异及早期选择研究

Variation Analysis and Early Selection for Eucalyptus grandis Provenances/Families in Central South Yunnan Province

摘要:

为筛选滇南亚高山的巨桉（Eucalyptus grandis）优良品系，对53月生的巨桉11种源173家系的生长性状进行分析。结果表明， 所有生长性状在种源和家系间均呈极显著差异；胸径、树高、单株材积、干形、分枝和冠幅的表型和遗传变异系数分别为26.90%~28.84%、23.84%~25.28%、62.34~67.55、13.04%~25.62%、13.04%~25.41%和35.07~39.93，各性状种源遗传力为0.94~0.96，家系遗传力为0.88~0.95。相关分析表明， 胸径与树高、单株材积、干形和冠幅呈极显著正相关，树高与其他性状均呈极显著正相关关系，干形与分枝的相关系数为0.70，冠幅与干形和分枝均呈负相关关系（r²=-0.03）。单株材积的遗传增益始终最大，以5%为入选率时，遗传增益高达66.11%；入选率不同，胸径与树高、干形与分枝的遗传增益的变化趋势基本相同， 但不同性状的遗传增益值的排序发生变化。以10%为入选率，经综合指数选择有17个家系入选，均来自1号（昆士兰Copperlode）、4号（昆士兰Koombooloomba）、6号（昆士兰Copperlode Falls Dam）、7号（昆士兰Bambaroo）、9号（福建天马东溪）和11号（四川乐山）种源，2号（昆士兰Ravenshoe）和8号（昆士兰Tully Gorge National Park）种源表现最差，排前6名的家系为289号、283号、2号、42号、121号和82号，也分别分布在入选种源中，说明入选家系不仅生长优良而且遗传多样性比较丰富。

Abstract:

In order to select excellent strains of Eucalyptus grandis, the growth traits, quality traits and crown width of 173 families from 11 provenances at 53-month-old grown in alpestrine of south Yunnan were analyzed. The results showed that there were significant differences in growth traits, quality traits and crown width among provenances and families. The phenotypic and genetic variation coefficients of DBH, H, V, stem form, branch and crown width were 26.90%~28.84%, 23.84%~25.28%, 62.34~67.55, 13.04%~25.62%, 13.04%~25.41% and 35.07~39.93, respectively. The provenance heritabilities were ranged from 0.94 to 0.96 and the family heritabilities were ranged from 0.88 to 0.95. The correlation analysis showed that there were significant positive correlations between DBH with H, V, stem form and crown width, also between H with other traits. The correlation coefficient between stem form and branch were 0.70, while that between crown width with stem form and branch were -0.03. The genetic gain of V was the biggest among all traits, and it was 66.11% by 5% selection rate. The change trend of genetic gain in H, DBH, stem form and branch were similar under different selection rate whereas the rank of their genetic gain was different. The 17 families were selected under 10% selection rate by comprehensive index selection, which derived from No. 1 (Copperlode, QLD), No. 4 (Koombooloomba, QLD), No. 6 (Copperlode Falls Dam, QLD), No. 7 (Bambaroo, QLD), No. 9 (Tianma, Dongxi, Fujian), and No. 11 (Leshan, Sichuan) provenances. The provenances of No. 2 (Ravenshoe, QLD) and No. 8 (Tully Gorge National Park, QLD) grow slowly. The best six families were No. 289, No. 283, No. 2, No. 42, No. 121 and No. 82, derived from six selected provenances, indicating that the selected families not only had good growth and branch traits but also had rich genetic diversity.