G×E Analysis of Growth Traits of Betula platyphylla Clones at Three Separated Sites in Northeastern China

To select elite materials,the growth traits of 32 Betula platyphylla clones at three separated northern sites in Northeast China were investigated and analyzed.The results showed that there were significant differences among all variation sources in the different investigated traits(P<0.01).Except for the carbon contents,all the coeffi-cients of phenotypic variation of the other investigated traits were higher than 10%.The repeatability of different traits ranged from 0.760 to 0.998.Correlation analysis showed that tree height were significantly correlated with diameter at breast height,but neither was significantly correlated with leaf traits nor element contents.Additive main effects and multiplicative interaction analysis showed that genotype,environment and genotype×environment interactions were significantly different in diameter at breast height,which indicated that environment had a significant effect on genotype.Comprehensive assessment results showed that three clones with high and stable diameters at breast height were selected,and the genetic gains of diameter at breast height on sites Maoershan,Qingan,and Yongji were 21.24%,20.58%,and 38.65%,respectively.The results could provide a theoretical basis for elite clone selection in B.platyphylla and other broad leaved species.