鹅掌楸种源家系幼林生长性状变异及选择研究OA

Genetic variation in early growth traits of Liriodendron chinense is critical for its genetic improvement and elite family selection.In this study,field trials were carried out in Leping,Jiangxi province,covering 59 half-sib families from 11 provenances.Tree height and diameter at breast height(DBH)of 4-year-old L.chinense juvenile individuals were measured to characterize phenotypic and genetic differences among families.Linear mixed-effect models were used to analyse the effects of provenance,block and family on growth traits.Variance components and family heritability were estimated using restricted maxi-mum likelihood and breeding values were predicted by best linear unbiased prediction(BLUP).A heritability-weighted index was constructed for comprehensive family evalua-tion.The results indicated prominent phenotypic variations in both DBH and tree height.Spe-cifically,DBH exhibited a higher coefficient of variation(14.83%)than tree height(10.12%).Block effect exerted a significant influence on DBH growth(P<0.05),while tree height was significantly affected by provenance variation(P<0.05).The family heritability of DBH and tree height were 0.657 and 0.698,respectively,indicating that both traits are un-der strong genetic control.Six elite families,including CQYY-7,YNJP-18,YNJP-4,YNJP-15 and SCXY-1,were ultimately selected based on comprehensive BLUP scores.This study confirms that juvenile L.chinense growth traits have considerable genetic im-provement potential.The integration of linear mixed-effects model and BLUP provides an effective and accurate method for the early screening of superior L.chinense families,offer-ing reliable support for the selective breeding and targeted cultivation of L.chinense.