10年生木荷生长和材性性状家系变异及选择

【目的】分析10年生木荷优树自由授粉家系生长和材性性状的遗传变异及相关性,选择生长兼材性优良的家系,为木荷高世代育种和改良提供材料。【方法】以2008年在福建建瓯营建的113个木荷优树自由授粉家系为材料,探讨树高、胸径和木材基本密度的遗传变异规律,并进行遗传参数估算和相关性分析,在此基础上选择生长和材性兼优的家系。【结果】10年生木荷优树自由授粉家系的树高、胸径和木材基本密度均在家系间呈极显著差异。木材基本密度受遗传效应影响较大,而树高和胸径除受遗传控制,还受遗传和环境互作的影响。树高和胸径在产地间差异极显著,而木材基本密度差异不显著。表型变异系数和遗传变异系数由大到小依次为胸径(12.13%和7.74%)、树高(8.28%和3.58%)、木材基本密度(2.82%和1.92%),说明胸径在家系间变异较大,木材基本密度变异较小。遗传力估算结果显示,家系遗传力和单株遗传力由大到小依次为木材基本密度(0.48和0.42)、胸径(0.44和0.35)、树高(0.32和0.26),它们受中度偏强的遗传控制;表型和遗传相关结果显示,树高与胸径间呈极显著正相关,而树高和胸径与木材基本密度间无相关性,因此,生长性状与木材基本密度可独立选择。以分别大于家系胸径均值的10%和木材基本密度平均值为选择标准,选择出13个生长兼材性优良的家系,胸径和木材基本密度的平均遗传增益分别为6.99%和1.18%,平均现实增益分别为16.08%和2.42%。【结论】供试木荷生长性状除遗传控制,还受遗传与环境互作的影响,木材基本密度受遗传效应的影响较大。胸径具有较强的变异性;木材基本密度受遗传控制较强。生长性状和木材基本密度可独立选择。本次从113个木荷优树自由授粉家系中选择出了13个生长兼材性优良的家系。

A variation and selection of growth and wood traits for 10-year-old Schima superba

【Objective】 To analyze the genetic variation and correlation of growth and wood traits in 10-year-old Schima superba open-pollinated families and select families with excellent growth and wood traits that can provide quality material for high-generation breeding and improvement of S. superba. 【Method】The 113 open-pollinated families of S. superba plus trees established in Jian’ou of Fujian Province in 2008 were used as experimental materials. Genetic variation, genetic parameter estimation and the correlation analysis were carried out on tree height, diameter at breast height (DBH) and basic wood density. On this basis, families with high-quality growth and wood traits were selected. 【Result】 The tree height, DBH and basic wood density of the 10-year-old S. superba open-pollinated families showed significant differences among families. The basic wood density was greatly affected by genetic effects, while tree height and DBH were affected by genetic and environmental effects in addition to the genetic control. The differences in tree height and DBH between producing areas were highly significant, while the differences in basic wood density were not significant. The phenotype variation coefficient and genetic variation coefficient were followed by DBH (12.13%, 7.74%), tree height (8.28%, 3.58%), and basic wood density (2.82%, 1.92%), indicating a large variation between families in DBH and a small variation in basic wood density. The results of heritability estimation showed that the family heritability and the individual heritability were in the order of basic wood density (0.48, 0.42), DBH (0.44, 0.35) and tree height (0.32, 0.26), which were subject to moderate to strong genetic control. Phenotypic and genetic correlation results showed that there was a very significant positive correlation between tree height and DBH, while there was no correlation between growth traits and basic wood density. Therefore, growth traits and basic wood density could be independently selected. Thirteen families with excellent growth and wood traits were selected with the criteria of higher than 10% of the mean DBH and the average basic wood density. The average genetic gains of DBH and basic wood density were 6.99% and 1.18%, respectively, and the average real gains were 16.08% and 2.42%, respectively. 【Conclusion】 The tree height and DBH were affected by genetic and environmental interactions in addition to the genetic control, while the basic wood density was greatly affected by genetic effects. The DBH had strong variability, and the basic wood density was strongly controlled by genetics. Growth traits and basic wood density could be selected independently. Thirteen families with excellent growth and wood traits were selected.