Genetic analysis of crossing effects for growth traits of Pinus massoniana and selection of cross combinations

Abstract

Two groups of filial generations derived from two different Pinus massoniana complete-diallel crosses were analyzed. Results show that the general combining ability (GCA), specific combining ability (SCA) and reciprocal effects were significant for some growth traits, including height, DBH and volume index. The heredity of these growth traits was controlled by additive and nonadditive genes, of which the additive genes played a dominant role. The epistatic effect was greater for group I (cross in 1992) than group II (cross in 1993). The SCA of P. massoniana growth traits was significantly greater than GCA, which may be related to different geographical provenance for parents and the indirect selection by GCA. Inbreeding depression was commonly observed for P. massoniana growth traits. The extent of inbreeding depression was K17.8% -K18.4%, K23.3% -K27.7% and K44.3%-K50.6% for height, DBH and volume index, respectively. It was observed that parents with small GCA values exhibited a greater extent of inbreeding depression. Large differences in hybrid vigor of different crosses were observed and the difference between original cross and reciprocal cross was not significant. Based on the volume index, 10 fine crosses were selected for two groups respectively, and the average increment of volume index was 59.41% and 41.76%, respectively, in comparison with the average of the testing groups, and was 100.58% and 74.61% in comparison with the local commercial variety.

Age Trends in Genetic Parameters for Growth and Resin-Yielding Capacity in Masson Pine

“…This may not be surprising considering that family was detected having strong influence on growth traits of masson pine (HONG et al, 2010;JIN et al, 2008aJIN et al, , 2008bZHOU et al, 2008;. Since there were highly positive genetic correlation between RYC and growth characteristics in this study (Table 8), it is possible to detect the significant effect of family on RYC.…”