思茅松半同胞和全同胞子代测定林生长性状遗传分析与选择

Genetic analysis of growth traits in half-sib and full-sib progenies and superior genetic materials selection of Pinus kesiya var.langbianensis

【目的】阐明思茅松生长性状的遗传变异规律和遗传控制程度,评价参试家系的生长表现,筛选优质的育种材料。【方法】以14年生思茅松半同胞子代测定林和6年生全同胞子代测定林为研究对象,对树高、胸径、材积3个生长性状进行遗传参数估算和性状相关性分析,并利用育种值和遗传值进行优良家系(组合)和优良单株选择。【结果】2类子代测定林3个生长性状的表型和遗传变异系数依次为材积>胸径>树高,生长性状间的遗传相关均达极显著水平(P <0.01);14年生半同胞子代测定林树高、胸径和材积性状的家系遗传力分别为0.680、0.691和0.748,单株遗传力分别为0.656、0.234和0.321,以材积为目标性状,根据参试家系育种值选出6个优良家系,其材积较对照提高37.9%~48.0%,入选优良家系材积的遗传增益为11.47%,按参试子代个体材积育种值选出52株优良单株,有78%的比例来源于优良家系,入选优良单株材积的遗传增益达30.64%;6年生全同胞子代测定林生长性状受中等强度的显性遗传效应影响,树高、胸径和材积的广义家系遗传力分别为0.245、0.256和0.204,根据遗传值选出2个优良组合,其材积遗传增益为15.53%。【结论】思茅松子测林材积性状的表型和遗传变异系数相对较高,适宜作为遗传选择的主要生长性状,基于遗传分析对思茅松子代测定林进行评价和选择能获得较好的遗传增益,可为思茅松的持续遗传改良选出较好的遗传材料。

【Objective】To clarify genetic variation,genetic control degree of Pinus kesiya var.langbianensis,evaluate the growth performance of tested families,provide high quality breeding materials.【Method】The genetic parameter estimation and correlation analysis were carried out for three growth traits including tree height,diameter at breast height(DBH)and volume in 14-year-old half-sib progeny and 6-year-old full-sib progeny of P.kesiya var.langbianensis.The breeding value and genetic value were used to select the superior families(mating combinations)and superior individuals.【Result】The phenotypic and genetic variation coefficients of three growth traits were volume>DBH>height in the progenies,and the genetic correlation among the three traits was extremely significant(P<0.01).The family heritability of height,DBH and volume of half-sib progeny were 0.680,0.691 and 0.748 respectively,and the individual heritability were 0.656,0.234 and 0.321 respectively.Taking the volume as the target trait,6 superior families were selected according to the breeding value of the tested families.The volume increased by 37.9%-48.0%compared to the control,and the genetic gain of the volume was 11.47%.52 superior individuals were selected based on the individual volume breeding values of the tested offspring,with 78%of the proportion coming from selected superior families.And the genetic gain of the volume of the selected superior individuals was 30.64%.The growth traits of six-year-old full-sib progeny were significantly affected by the dominant genetic effect.The broad-sense family heritability of tree height,DBH and volume were 0.245,0.256 and 0.204 respectively.Two superior were selected using genetic values,and the genetic gain of volume was 15.53%.【Conclusion】The phenotypic and genetic variation coefficients of volume traits of P.kesiya var.langbianensis progeny test forest were relatively high,and the volume was suitable as the main growth trait of genetic selection.Evaluation and selection based on genetic analysis can obtain better genetic gain,and can provide superior genetic materials for the forward improvement of P.kesiya var.langbianensis.