高粱重组自交系耐盐性相关性状遗传分析

Genetic Analysis of Salt Tolerance Related Traits in Sorghum Recombinant Inbred Lines

耐盐是高粱重要的农艺性状,耐盐遗传分析对于高粱育种具有重要意义。为选育耐盐高粱新品种、研究耐盐遗传规律,选用耐盐性品种三尺三和盐敏感品种Tx622B杂交得到的482个F_5重组自交系群体为试验材料,采用砂培法进行栽培,对群体的发芽率、苗高、鲜质量和干质量4个性状进行苗期耐盐性的鉴定,利用单世代联合的数量性状分离分析方法来进行高粱耐盐性状的遗传分析。结果表明:耐盐性品种三尺三和盐敏感品种Tx622B亲本间的耐盐性状差异显著,F_5群体材料耐盐性状发芽率、苗高、鲜质量、干质量的相对平均值均在亲本之间,杂交后代存在不同程度的耐盐性变异,符合数量性状遗传;对4个性状耐盐指数进行相关性分析表明,4个性状两两间存在极显著的正相关性;高粱分离群体的相对发芽率、相对苗高、相对鲜质量和相对干质量均呈单峰偏态分布,可进行单世代遗传分析,存在主基因效应;通过遗传模型分析发现,高粱重组自交系F_5群体耐盐性对盐敏感性为显性,高粱耐盐性状遗传符合2对主基因的完全显性(B-5)遗传模型;在B-5模型中,发芽率主基因遗传率为40. 94%;苗高主基因遗传率为31. 22%;鲜质量主基因遗传率为39. 19%;干质量主基因遗传率为63. 98%。发芽率、苗高、鲜质量和干质量作为高粱耐盐性评价的主要性状具有较高的遗传力,对于高粱耐盐品种的选择和培育具有深远的意义。

Sah tolerance is an important agronomic trait of sorghum. Salt tolerance genetic analysis is important for sorghum breeding. In order to select new varieties of salt-tolerant sorghum and study the genetic rules of salt tolerance,482 F5 recombinant inbred lines were obtained from the salt-tolerant cultivar Sanchisan and salt-sensitive cultivars Tx622B,and the germination rate, seedling height, fresh weight and dry weight were used to identify salt tolerance at seedling stage. Genetic analysis was carried out by single-generation combined quantitative trait analysis. The results showed that the sal-tolerance traits of the Sanchisan and salt-sensitive cultivars Tx622B were significantly different. The relative mean values of germination rate,seedling height, fresh weight and dry weight of the F5 generation group were all different among parents, and the tolerance to salt tolerance was different in different degree. The germination rate, seedling height, fresh weight and dry weight were analyzed. There were significant positive correlations between the two traits. The relative germination rate, relative seedling height, relative fresh weight and relative（B-5） genetic model of two pairs of major genes were found by genetic model analysis. Through genetic model analysis, it was found that salt tolerance of F5 population of recombinant inbred lines of sorghum was dominant to salt, and inheritance of salt-tolerance trait of sorghum was in line with complete dominant（ B-5 ）genetic model of two major genes. The heritability of the major gene of germination rate was 40.94%. The heritability of major gene of seedling height was 31.22%. The heritability of major gene of fresh weight was 39. 19%. The heritability of main gene of dry weight was 63.98%. The germination rate, seedling height,fresh weight and dry weight have high heritability as the main characters of salt tolerance evaluation, and have far-reaching significance for the selection and cultivation of sorghum salt-tolerant varieties.