木荷全同胞家系生长与分枝性状的遗传变异及效应分析

Genetic variation and effect of growth and branching traits in full-sib families of Schima superba

【目的】揭示木荷Schima superba F1代全同胞家系的生长与分枝性状的遗传变异规律,为木荷科学育种提供依据。【方法】以2015年在浙江龙泉营建的4×4半双列交配设计的木荷全同胞家系测定林为研究对象,对木荷亲本组合生长与分枝性状的遗传变异参数、一般配合力(GCA)和特殊配合力(SCA)等进行分析。【结果】6年生木荷全同胞家系间的生长和分枝性状存在极显著差异(P<0.01)。生长和分枝性状的变异系数为20%~53%。木荷的生长和分枝性状受较强的遗传控制(全同胞遗传率为0.86~0.93),其中,生长性状的父本遗传率更高,受基因加性和显性效应共同控制;分枝性状的母本遗传率更高,受基因加性效应控制。相关分析表明:木荷全同胞子代生长和分枝性状存在极显著的表型相关(r=0.20~0.87,P<0.01),胸径生长与一级分枝数、枝下高呈极显著遗传相关(r=0.67~0.70,P<0.01)。生长和分枝性状的GCA和SCA效应均达到显著(P<0.05)和极显著(P<0.01)水平。根据GCA和SCA的结果,认为江西上犹和福建连城的优树为优良亲本,两者组合具有速生性状的特殊配合力效应,初选的6株优良全同胞子代可作为2代育种亲本材料。【结论】6年生木荷全同胞家系生长和分枝性状受较强遗传控制,生长性状父本控制力更强,分枝性状母本控制力更强。根据生长性状和分枝性状分别对亲本进行选配,可以得到速生优质的超级亲本组合。

[Objective]This study aims to reveal the heredity and variation of the growth and branching traits of the full-sib families of Schima superba and provide reference for scientific breeding.[Method]Taking a 4×4 half diallel mating design that was conducted in Longquan of Zhejiang Province in 2015 as the research object,the genetic variation parameters,general combining ability(GCA),and special combining ability(SCA)of the growth and branching characters were analyzed.[Result]The growth and branching traits differed significantly across the 6-year-old full-sib families(P<0.01).The coefficient of variation for the growth and branching traits ranged from 20%to 53%.The growth and branching traits were under strong genetic control,and the heritability of full-sib families was 0.86−0.93.The paternal heritability of the growth traits was higher,which was jointly controlled by gene additive and dominant effects.The maternal heritability of branching traits was higher,which was controlled by gene additive effect.The correlation analysis showed that there was a significant phenotypic correlation between the growth and branching traits(r=0.20−0.87,P<0.01),and there was a significant genetic correlation between DBH growth and bole height and primary branch number(r=0.67−0.70,P<0.01).The GCA and SCA effects of the growth and branching traits reached significant(P<0.05)and extremely significant(P<0.01)levels.According to the results of GCA and SCA,SY42 in Shangyou of Jiangxi and LC31 in Liancheng of Fujian were considered as excellent parents,and SY42×LC31 combination had special combining ability with fast-growing characters.In addition,the six super-crossing progenies could be used as parent materials for the second-generation breeding.[Conclusion]The growth and branching traits of full-sib families of S.superba are under strong genetic control,with stronger paternal control over growth traits and stronger maternal control over branching traits.Parents can be selected according to the growth and branching traits,and the super parent combination with fast growth and high quality can be obtained.