木荷种子园自由授粉家系生长遗传变异及初选

Genetic variation and selection of the free-pollinated families in Schima superba seed orchard

【目的】分析7年生木荷1代无性系种子园自由授粉家系生长性状的遗传变异及遗传增益,评价种子园亲本优劣,为木荷高世代育种提供优良材料。【方法】以2014年营建于江西信丰的50个木荷1代无性系种子园自由授粉家系为材料,分析树高、胸径和材积指数的遗传变异规律及其所受的遗传控制,估算现实增益和遗传增益,评价无性系亲本优劣,并选择优良家系。【结果】7年生木荷1代种子园自由授粉家系的树高、胸径和材积指数在家系间均存在丰富的差异,表型和遗传变异系数分别在7.89%~27.06%和6.28%~24.60%之间,胸径的变异大于树高。各性状的家系遗传力(0.42~0.47)均高于单株遗传力(0.19~0.27),受强度的遗传控制,其中树高所受的遗传控制较强。木荷1代无性系种子园自由授粉家系的生长表现均明显优于未经遗传改良的商品对照,以树高和胸径均高于商品对照的25%为标准,初选出16个优良家系,如YP35、YP7和GT2,入选家系的树高、胸径和材积指数的平均现实增益分别为34.31%、38.57%和170.02%,平均遗传增益分别为16.12%、16.20%和74.81%。【结论】木荷1代无性系种子园遗传改良效果显著,为种子园无性系的去劣疏伐提供了理论依据,从优良家系中筛选出的优良个体可作为下一代育种亲本。

【Objective】In this article,the genetic variation and genetic gain of the growth traits of the free-pollinated families in the 7-year-old S.superba seed orchard were analyzed,and the parents of the seed orchard were evaluated to provide excellent materials for the high-generation breeding of S.superba.【Method】50 free-pollinated families of the first-generation clone of S.superba seed orchard in Xinfeng,Jiangxi Province in 2014 were used as experiment materials.The genetic variation and genetic control of tree height,DBH and volume index were analyzed,and the actual gain and genetic gain were estimated.On this basis,the parents were evaluated and the excellent families were selected.【Result】The tree height,DBH and volume index of the free-pollinated families of the first generation of 7-year-old S.superba seed orchard showed significant differences.The phenotypic and genetic variation coefficients ranged between 7.89%-27.06%and 6.28%-24.60%,respectively.The variation of DBH was greater than that of tree height.The family heritability of each trait(0.42-0.47)was higher than the individual heritability(0.19-0.27),which was subject to strong genetic control,and the genetic control was greater in tree height.The growth performance of the free-pollinated families of the first-generation clone of S.superba seed orchard was significantly better than that of the commercial control without genetic improvement.Based on the standard that the tree height and DBH were 25%higher than those of the commercial control,16 excellent families,such as YP35,YP7 and GT2 were selected.The average actual gains were 34.31%,38.57%and 170.02%,respectively,and the average genetic gains were 16.12%,16.20%and 74.81%.【Conclusion】The genetic improvement effect of the first generation clone of S.superba seed orchard is remarkable,which provides a basis for the thinning of clones in seed orchards.The excellent individuals selected from the excellent families can be used as breeding parents for the next generation.