杉木两种交配子代生长性状变异及优良家系选择

The variation of growth properties and screening on superior families among two mating progenies in Chinese fir

1991年在贵州省黎平县布置了杉木16个自由授粉和8个单交家系的子代测定,调查分析了两种交配方式下3,4,5,6和16 a的子代生长性状。结果表明,参试家系间生长性状变异丰富,具有真实的遗传变异,家系遗传力在0.401 4～0.760 8之间,自由授粉家系生长表现总体优于单交家系。优良家系的早期选择可在第5年开始,6a选择的可靠性更高。在30%的入选率下,以材积为主要指标,兼顾树高和胸径进行选择,评选了7个最优家系。最优家系16 a平均单株材积0.097 76 m^3,遗传增益分别比初级种子园自由授粉混系（CK1）、黎平优树（CK2）和群体均值提高24.6%,45.6%和18.4%。最优家系适宜在贵州黎平周边立地指数14以上造林地推广应用,其材积遗传增益可超过18.4%。

The progeny tests on sixteen open pollination and eight single cross families of Chinese fir were arranged at Liping County,Guizhou Province in 1991,and the progeny growth traits of 3,4,5,6 and 16 years-old in two mating models（ open pollination and single cross） were investigated and analyzed. The results showed that the growth trait of families presented abundant variation and actual genetic variation,and the family heritabilities were from 0. 401 4 to 0. 760 8,and the growth performance of the open pollination families was superior to that of the single cross families. The early selection of the superior families could begin at the 5th year,and would obtain higher reliability at the 6th year. Under the selection rate of 30% for family,according to individual volume mainly in combination with height and DBH indices,seven super fast-growing families were selected. The average individual volume of seven superior families at the age of 16-year was0. 097 76 m^3,and the volume genetic gain increased by 24. 63% as compared to the first generation seed mixed families（ CK1）,by 45. 6% as compared to the elite tree of Liping County from superior provenances（ CK2）,and by 18. 4% as compared to the population average value,respectively. These superior families were very suitable to be utilized for extension at the forest land with site index of over 14 around Liping County in Guizhou Province,and the genetic gain for volume was estimated to be over 18. 4%.