Genetic Parameters and Selection of Clones and Families of Pinus koraiensis Using Principal Components and Multi-Trait Method

Abstract

Pinus koraiensis is recognized as one of the most valuable timber and economic tree species. Fruiting properties and growth traits are important characteristics for P. koraiensis breeding, and the relationship between fruiting properties of parents and growth traits of progeny is needed for better understanding. In this study, 71 parental clones and open-pollinated progeny families from the same plus trees were used as materials, and four fruiting properties (cone number per single tree, seed number per single cone, thousand-seed weight, and fruiting individual percentage) and four growth traits (height, diameter at breast height, volume, and survival individual percentage) were measured and calculated. There were significant variations in fruiting properties and growth traits among parental clones and progeny families. For fruiting properties, the phenotypic and genotypic coefficients of variation ranged from 16.51% to 175.34% and from 6.75% to 20.26%, respectively, and the repeatability ranged from 0.3430 to 0.9438. For growth traits, the phenotypic and genotypic coefficients of variation ranged from 15.68% to 39.89% and from 3.51% to 25.99%, respectively, and the broad-sense and narrow-sense heritability ranged from 0.7149 to 0.9681 and from 0.3648 to 0.4614, respectively. There were extremely significant positive correlations between cone number per single tree and fruiting individual percentage, as well as between height, diameter at breast height, and volume. Nevertheless, there was no significant correlation between fruiting properties of parental clones and growth traits of progeny families. Based on the integrated results of principal component analysis and the multi-trait comprehensive evaluation method, six clones (HS23, HS95, HS05, HS73, HS67, and HS17) and four families (HS37, HS17, HS60, and HS54) were selected as elite clones and families, respectively, and HS17 was identified as both an elite parental clone and an elite progeny family. The genetic and realistic gains of elite clones for fruiting properties ranged from 1.34% to 17.34% and from 1.50% to 47.22%, respectively, and the genetic and realistic gains of elite families for growth traits ranged from 4.85% to 33.90% and from 6.73% to 35.02%, respectively. The present study provides the foundation for reconstruction and upgrading of P. koraiensis seed orchards, which is helpful for increasing productivity and economic benefits.