5年生杉木无性系的遗传变异分析及多点联合选择OA

To screen for widely adaptable elite clones of Chinese fir(Cunninghamia lanceolata)for Nanping and Sanming regions in Fujian Province,combined determination and analysis were conducted on the 5-year-old Chinese fir clone experimental forests at three test sites:Fujian Yangkou State-owned Forest Farm,Jiangle State-owned Forest Farm,and Shaxian Guanzhuang State-owned Forest Farm.The results showed that at the age of 5 years,the average tree height,diameter at breast height(DBH),and individual timber volume of the tested clones reached 5.69 m,8.81 cm,and 0.022 41 m3,respectively.The growth performance of the experimental forests located at Yangkou and Guanzhuang sites was superior to that observed at the Jiangle site(P<0.05).The results from the multi-site combined analysis of variance indicated that differences(P<0.01)existed in the growth traits of the 33 tested clones with respect to the site main effect,clone main effect,and the site-clone interaction effect.Estimations of genetic parameters for growth traits at individual sites showed that the repeatability values for tree height,DBH,and timber volume ranged from 0.646 to 0.861,0.590 to 0.754,and 0.599 to 0.784,respectively,while the repeatability values of various traits from the combined analysis of variance across multiple sites reached 0.708,0.700,and 0.713,respectively.Genetic and phenotypic correlations(P<0.05)were observed among the growth traits of the tested clones.On the basis of timber volume performance,10 elite clones were selected from each site at a 30%selection rate.The average timber volumes of the selected clones were 0.030 66 m3,0.028 71 m3,and 0.023 11 m3 for Yangkou,Guanzhuang,and Jiangle sites,respectively.The average genetic gains in timber volume were 17.02%,15.62%,and 13.44%,representing increases of 21.71%,19.97%,and 30.27%over the overall mean of each site and 57.96%,63.43%,and 44.70%over the control('Minshan No.1').Through combined determination and analysis,four elite clones(No.57,No.35,No.31,and No.80)were selected for their fast growth,stability,and wide adaptability.At three test sites,their average tree height,DBH,and individual timber volume reached 6.06 m,9.66 cm,and 0.02809 m3,respectively,with an average genetic gain of 18.06%in timber volume.The growth traits of Chinese fir are under moderate to high genetic control,with significant site-clone interaction effects.