杉木第3代种子园自由授粉家系的遗传变异及早期选择

Genetic variation and early selection of open pollination progeny of Cunninghamia lanceolata in 3rd generation seed orchard

[目的]分析杉木第3代种子园自由授粉家系的生长性状表现及遗传变异规律,筛选出速生优良家系和优良单株。[方法]对福建省尤溪国有林场杉木第3代种子园自由授粉子代试验林开展遗传测定,基于10年生的树高、胸径和单株立木材积,分析杉木第3代种子园自由授粉家系生长性状的遗传变异规律,评选出早期生长表现优异的家系和个体。[结果]1~5年生杉木测定林树高和胸径年均生长量均稳定上升,5年生时分别达到0.99 m和1.4 cm;10年生平均树高、胸径和单株立木材积分别为8.66 m、12.1 cm和0.07637 m^(3),年均生长量分别达0.87 m、1.2 cm和0.00764 m^(3)。10年生杉木测定林树高、胸径及单株立木材积的广义遗传力分别为0.523、0.585和0.599,狭义遗传力分别为0.235、0.278及0.285,受到明显的遗传控制。以单株立木材积遗传增益高于5%为标准,筛选出20个速生优良家系,平均树高、胸径和单株立木材积分别达9.21 m、14.1 cm和0.10430 m^(3),平均遗传增益分别为1.48%、4.51%和10.42%。以单株立木材积遗传增益高于60%为标准,筛选出20个速生优良单株,平均树高、胸径和单株立木材积分别达12.88 m、23.6 cm和0.29534 m^(3),平均遗传增益分别达11.45%、26.48%和81.71%。[结论]筛选的杉木速生家系及优良单株生长优势明显,速生家系可在生产中推广造林,优良单株可作为杉木第4代育种和无性系选育的遗传资源。

[Purpose]Open pollination progeny of Chinese fir in the 3rd generation seed orchard were analyzed on genetic variation of growth traits to screen excellent fast-growing families and individual plants.[Method]Genetic testing was conducted on open pollination progeny of Chinese fir in the 3rd generation seed orchard of Fujian Youxi State-owned Forest Farm.Based on tree height,diameter at breast height(DBH),and individual tree volume of 10-year-old Chinese fir,their genetic variations of growth traits were analyzed,followed by the selection of family and individual with excellent early growth performance.[Result]The average annual growth of tree height and DBH of Chinese fir tested plantation both steadily increased from the 1st year to the 5th year,reaching 0.99 m and 1.4 cm at the 5th year,respectively;at the 10th year,the average tree height,DBH and individual tree volume arrived at 8.66 m,12.1 cm,and 0.07637 m^(3),respectively,with average annual growth rates of 0.87 m,1.2 cm,and 0.00764 m^(3),respectively.The 10-year-old test plantation had broad heritability of tree height,DBH,and individual tree volume at 0.523,0.585 and 0.599,and narrow heritability at 0.235,0.278 and 0.285,respectively,implying significant genetic control on growth traits.Basing on the criteria of individual tree volume with genetic gain higher than 5%,20 fast-growing families were selected;their average tree height,DBH and tree volume were 9.21 m,14.1 cm and 0.10430 m^(3),with genetic gains of 1.48%,4.51% and 10.42%,respectively.On the basis of individual tree volume with genetic gain higher than 60%,20 fast-growing individuals were selected;their average tree height,DBH and individual tree volume reached 12.88 m,23.6 cm and 0.29534 m^(3),respectively,with genetic gain of 11.45%,26.48% and 81.71%,respectively.[Conclusion]The selected fast-growing families and individuals demonstrated obvious growth advantages with high application in afforestation,and can be used as important genetic resources for the 4th generation breeding materials or clone breeding of Chinese fir.