广东乐昌杉木种质资源库无性系生长与材质性状的变异分析

Variation Analysis on Growth and Wood Quality Traits of Cunninghamia lanceolata Clones in Lechang Germplasm Bank

对杉木种质资源库中103个嫁接无性系树高、胸径、材积、木材基本密度、管胞长度、管胞宽度、管胞长宽比等生长材质性状进行测定分析发现:各性状在无性系间差异显著至极显著,广泛变异,其中以材积变异程度最大,变异系数为36.23%;树高、胸径、材积、木材基本密度、管胞宽度重复力相对较高(>50%)。遗传相关分析结果表明:木材基本密度和生长性状及管胞宽度间、管胞宽度与管胞长宽比间均表现为遗传负相关;而不同生长性状间、管胞长度与管胞宽度及管胞长宽比间、木材基本密度和管胞长宽比间、管胞长度和管胞长宽比与胸径材积间则显示为遗传正相关。此外,采用基于指数选择的无约束和约束法分别对无性系进行综合选择,发现均有一定数目无性系入选;与无约束选择相比,约束选择有效排除木材基本密度过小无性系,选择效果更为明显。约束选择中,在材积获得28.77%遗传增益时(20%入选率下),木材基本密度遗传增益值达到最大;当材积实现最大遗传增益时(10%入选率下),管胞长度遗传增益值也有较大幅度提高(0.62%)。说明在杉木多性状综合选择中获得生长材质皆优无性系是可能的,进行改良也是可行的。

Some growth and wood quality traits of 103 clones of Cunninghamia lanceolata in ＇ Longshan＇ Germplasm Bank were tested to analyze the differences among the clones in these criteria including tree height （TH）, diameter at breast height （DBH）, standing volume （VOL） and wood basic density （DEN）, tracheid length （TL） and width （TW）, as well as length-width ratio of tracheid （LRT）. The variance analysis results indi- cated that all the traits varied either significantly or extremely significantly among the clones. There was the largest difference in the VOL trait among the all criteria measured, whose variation coefficient was 36. 23%. The repeat- ability of the traits of TH, DBH, VOL, and DEN, and TW was relatively high （ 〉 50% ）. The genetic correlation analysis indicated that the trait of DEN was negatively correlated with TH, DBH, VOL, TW criteria, and there was negative correlation-ship between TW and LRT criteria. There were positive correlations among the different growthtraits, between TL and TW, TL and LRT, DEN and LRT, TL and LRT, DBH and VOL. A considerable number of C. lanceolata clones were separately selected as superior ones by the index-free or index-restricted methods. Com- pared to the index-free method, the restricted approach was more efficient in selection that could effectively exclude the clones in low DEN level. Profoundly, when genetic gain in VOL was 28.77% （20% was the threshold） ob- tained by the index-restricted method, the DEN trait represented a peak in genetic gain. While the maximum genet- ic gain of VOL was achieved, a moderate genetic gain for TL（0.62% ）was observed （under the threshold of 10% by index-restricted method）. Thus, it was hypothesized that the comprehensive selection by multiple criteria and improvement of C. lanceheolata clones simultaneously with optimal growth and wood quality traits was possible.