Line × tester analysis for growth and biomass characteristics of Populus deltoides Bartr.

Abstract

Line × tester analysis was carried out in Populus deltioides to determine the genetic interaction in the expression of various quantitative characters related to productivity. Combining ability revealed that the estimates of SCA variance (σ2SCA) were more than the GCA variance (σ2GCA) for all the characters studied. Later the gene action study revealed that dominance variance was observed more than the additive variance for all the parameters studied. The proportional contribution of testers were higher than individual contribution of lines or line × tester interaction except for plant height, collar diameter, number of leaves/plant, root length and fresh root weight where the contribution of interactions was more. The Line L-62/84 and tester L-17/92 was found to be good general combiners and thus appeared to be worthy of exploiting in Populus deltioides 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 L-62/84 X S7C1 was found to be the most promising family for growth and biomass characters and is recommended for within family selection followed by heterotic breeding.