8年生马尾松二代种子园控制授粉子代生长性状和形质性状的遗传变异与选择

Genetic Variation and Selection of Growth and Morphological Traits in Filial Generation from Second Generation Clonal Pinus massoniana Seed Orchard

为揭示马尾松Pinus massoniana三代选择群体生长性状的遗传变异规律,为高阶遗传改良筛选优良种质,为育种亲本评价奠定基础,本研究以营建在浙江省淳安县十八坞林场的8年生马尾松二代种子园控制授粉子代家系林为试验材料,测定其树高、胸径、单株材积等主要性状,分析其遗传变异、遗传力和性状间的相关性。结果表明,8年生马尾松二代种子园控制授粉子代的生长性状(树高、胸径和单株材积)以及形质性状(冠幅和干形)在家系间均存在极显著差异,材积的表型变异系数和遗传变异系数均最大,表明材积在遗传水平和表型水平上均存在一定程度的变异潜力;各生长性状的单株遗传力变幅为0.15~0.62,家系遗传力变幅为0.52~0.82,说明在优树选择时主要以家系选择联合家系内单株选择为主。按照20%入选率,筛选出8个优良家系,单株材积的遗传增益为22.05%~36.60%,现实遗传增益为28.60%~43.48%,均值较CK1(当地普通种)增加128.26%~152.25%,较CK2(种子园混系种)增加9.13%~19.33%;按照5%入选率筛选出91株优良单株,分布在26个家系中,与群体均值相比单株材积的遗传增益均值达80.12%。综上,8年生马尾松二代种子园控制授粉子代林具有较高的遗传变异潜力,通过遗传评价有助于种子园建园亲本的再选择,同时,选择的优良种质可作为高阶遗传改良的育种亲本进入下一育种阶段。

In 2013,seeds of 38 families of Pinus massoniana from second generation clonal seed orchard,of one common family and of second generation clone as CK1 and CK2 were collected in Chun’an,Zhejiang province.In 2014,seedling cultivation was carried out,and in March 2015,experimental forest of above-mentioned seedlings was planted.In November 2011,tally was made on the plantation.The result demonstrated that here were extremely significant differences among families in the growth traits(tree height,DBH and single plant volume)and morphological traits(crown width and trunk straightness)of different families.The phenotypic variation coefficient of volume and genetic variation coefficient were both the largest,indicating that the volume had variation potential at both genetic level and phenotypic level.The variation range of single plant heritability for growth trait was 0.15-0.62,and the variation range of family heritability was 0.52-0.82,indicating that the fine tree selection was mainly based on family selection combined with single plant selection within the family.Eight excellent families were selected according to the 20%selection rate,and the individual genetic gain of volume was 22.05%-36.60%,and the actual one was 28.60%-43.48%.The average genetic gain was 128.26%-152.25%higher than CK1 and 9.13%-19.33%higher than CK2.According to the 5%selection rate,91 excellent individual plants of 26 families were selected.Compared with the average of the forest,the individual genetic gain of volume was 80.12%.