Genetic variation analysis and comprehensive evaluation of multiple traits among Larix olgensis families

In forest genetics research, precise evaluation of half-sib families provides essential insights for the selection and improvement of key species. This study systematically examined 40 half-sib families of L. olgensis from northeast China, analyzed 21 traits related to growth, form, wood, photosynthesis, and physiological traits. The research employed analysis of variance (ANOVA), genetic parameter estimation, and correlation analysis to assess family variation and trait relationships. The results indicated that 16 traits differed significant or highly significant (P < 0.05) among families. The coefficient of variation (CV) ranged from 7.78% to 65.16%, and family heritability ranged from 0.037 to 0.835. Wood traits showed negative correlations with growth and form traits. Based on average realized gains, we identified the estimation method of breeding value as optimal, leading to the selection of eight superior families at a 20% selection rate, with genetic gains ranged from 1.98% to 65.55%. The realized gains for tree height, diameter at breast height, volume, crown width, straightness, branching angle, lateral branch thickness, wood density, hemicellulose, holocellulose, and lignin were 5.97%, 8.11%, 20.44%, 10.32%, 3.06%, 3.22%, 10.74%, 1.99%, - 1.26%, - 1.36%, and 2.57%, respectively. These findings demonstrate that multi-trait, breeding-value-based selection effectively improves L. olgensis. This study provides both a theoretical basis and practical guidance for the genetic improvement of this economically important species.