Variation and Selection of Growth and Wood Property Traits in Cunninghamia lanceolata Full-sib Families

Abstract

【Objective】The study aims to prepare new and excellent Cunninghamia lanceolata (Lamb.) Hook germplasm materials and select superior families of C. lanceolata families, thus promoting the breeding process of higher generations of the species.【Method】Ten backbone parents of the second-generation improved seed orchard of C. lanceolata were used as hybrid parents, 30 full-sib families were obtained by artificial pollination, and full-sib progeny determination was conducted in multiple sites. Genetic variations of the growth and wood basic density of 8-year-old C. lanceolata were analyzed, and then the superior families were selected.【Result】Significant differences (P < 0.05) or extremely significant differences (P < 0.01) in tree height, diameter at breast height (DBH), volume per plant and wood basic density (WBD) were observed among families. Among them, volume per plant had the highest variation with phenotypic and genetic variation coefficients of 21.56%-28.53% and 12.18%-19.64%. Family heritability values of tree height, DBH, volume per plant and WBD were 0.1594, 0.2232, 0.1799 and 0.5357, respectively, which were benefit for family selection. The best linear unbiased prediction (BLUP) method was used to estimate the breeding values of growth and WBD of parents from full-sib families, and the special combining ability (SCA) of each hybrid combination was estimated and ranked according to the parental model. Based on the growth traits and WBD, two fast-growth families with good wood quality (family 5 and family 29) were selected. Of the two families, family 5 showed more gain in growth and wood traits with average gain of 6.02% and 26.47%, 8.21% and 14.25%, 15.82% and 34.56%, 7.25% and 5.35% in tree height, DBH, volume per plant and WBD when comparing to overall mean value and F2.5 population, respectively. There, family 5 should be an ideal fast-growth family with good quality.【Conclusion】The growth traits and WBD showed substantial variations among the 30 full-sib families of C. lanceolata. The selected families could be regarded as candidate families that are excellent both in growth and wood basic density.

Keywords

• cunninghamia lanceolata
• full-sib progeny test
• breeding value
• special combining ability
• excellent family selection