Analysis and Selection of Progeny Test Forest of the Open Pollinated Family of Japanese Larch

In order to select plus trees and provide materials for the establishment of advanced generation seed orchard in Xiaolongshan,growth characteristic analysis and genetic evaluation were conducted on the progeny test forest of the open pollinated family of Japanese larch.Most significant differences were observed in the diameter at breast height(DBH),tree height(H),and timber volume(V) among different families and groups.Most significant correlations existed among H,DBH,V,and crown size.The values of individual heritability of V,DBH,and H were 0.673 5,0.697 2,and 0.538 2,respectively,and the values of relative family heritability were 0.533 0,0.536 6,and 0.539 2,respectively.Values of individual heritability of V and DBH were higher than those of family heritability.Based on the timber volumes,as well as other traits,secondary generations of plus tree groups were obtained by combined selections of superior family and individual plus trees,which would be used as materials to establish the seed orchard,including 8 families and 30 individual plus trees.The average genetic gains of timber volumes of secondary generation plus tree selected were 159.7%.