Measurement and Selection of Progeny from Single-Pair Mating of Superior Germplasm of Pinus massoniana from Different Areas

To analyze the genetic variation patterns of growth traits in the progenies of single-pair crosses of superior germplasms of Masson pine, progeny tests were conducted using hybrid combinations of superior germplasms from eight distinct Masson pine provenances.At the age of eight years, the genetic variation patterns of tree height, diameter at breast height（DBH）,crown width, and individual tree volume were analyzed, and superior hybrid combinations and individual trees were selected.The result indicated that the growth traits exhibited substantial genetic variation both among combinations and individual trees.The broad-sense heritabilities for tree height, DBH,crown width, and individual tree volume were 0.418,0.692,0.563 and 0.728,respectively, while the narrow-sense heritabilities were 0.273,0.450,0.312 and 0.594,respectively.The family genetic variation coefficient was the highest for individual tree volume at 22.41%,followed by DBH and crown width at 11.33% and 9.42%,respectively, and the lowest for tree height at 5.68%.The growth traits of hybrid offspring from different Masson pine provenances were strongly genetically controlled, with volume being the most influenced by genetic effects.Superior hybrid combinations were selected based on individual tree volume exceeding the mean of the hybrid combinations by 10%,and superior individual trees were selected at 3% selection rate.This resulted in the identification of 2 superior hybrid combinations, 8 superior individual trees without pedigree relationships, and 12 superior individual trees from open-pollinated or hybrid combinations.Compared to the genetic gains in individual tree volume were 10.53%,85.04% and 62.19%,respectively; compared to the mean of the first-generation seed orchard, the realized gains in individual tree volume were 25.66%,169.50% and 132.26%,respectively.The 2 selected superior hybrid combinations can be promoted through targeted seed production, the 12 superior individual trees can be propagated through clonal methods, and the 8 superior individual trees without pedigree relationships can enrich the Masson pine breeding population.