Line × tester analysis for growth and biomass characteristics of Salix

Line × tester analysis was carried out in willows (Salix spp.) to determine the genetic interaction in the expression of various quantitative characters related to productivity. Combining ability revealed that the estimates of GCA variance (σ2 GCA) were more than the SCA variance (σ2 SCA) for all the characters studied. Later the gene action study revealed that additive variance was observed more than the dominance variance for all the parameters studied. The proportional contribution of lines were higher than individual contribution of testers or line × tester interaction except for fresh root weight, dry shoot weight, dry root weight and total dry weight where the contribution of interactions was more. Line PN 227 and tester Austree and J 795 were found to be good general combiners and thus appeared to be worthy of exploiting in Salix improvement through breeding and recurrent selection followed by cloning for developing commercial superior clones. On the basis of mean performance and significant desirable SCA effects, the combinations PN 227 × Austree, PN 227 × NZ 1140 and J 799 × Austree were found to be the most promising families for growth and biomass characters and are recommended for within family selections followed by heterotic breeding