结缕草属植物生殖性状的遗传分析

Genetic analysis of reproductive characters of zoysiagrass

选用2份生殖性状存在差异的结缕草(Z136)和中华结缕草(Z039)相互杂交,获得正反交F1分离群体,应用植物数量性状主基因+多基因混合遗传模型分析方法对F1群体的花序密度、生殖枝高度、花序长度、每穗小穗数、小穗长度、小穗宽度、小穗长度/宽度进行遗传分析,以初步明确这些性状的遗传特性。结果表明,1)在调查的7个性状中,正反交杂交后代中每一个性状的变异范围均超出了双亲的变异范围,不同性状的变异系数差异较大,花序密度的变异系数最大,其次为生殖枝高度和每穗粒数,小穗长度和宽度的变异最小,花序长度的变异居中。2)花序密度、生殖枝高度、小穗长度和小穗长/宽正反交后代的观测值存在显著差异,可能有母体遗传效应,花序长度、每穗粒数和小穗宽度正反交后代间的观测值无显著差异。3)花序密度正反交后代群体的最佳遗传模型为存在2对主基因控制的遗传模型,生殖枝高度、花序长度和小穗宽度正反交后代群体的最佳遗传模型均为A-0模型,即无主基因模型。每穗粒数正交为1对主基因的遗传模型,反交为无主基因模型,小穗长度的正交为无主基因模型,反交为1对主基因模型。小穗长/宽正交的最适遗传模型为B-1模型,即2对主基因的加性-显性-上位性遗传模型,主基因遗传率为42.72%,反交群体的最适遗传模型为B-2模型,即2对主基因的加性-显性遗传模型,主基因遗传率为98.81%。

The heredity of reproductive characters, including inflorescence density, reproductive branch height, inflorescence length, specule number of each spike, specule length, specule width and speeule length/width ratio, in two F1 populations of Z136 × Z039 and Z039 × Z136 was analyzed by major gene and polygene mixed genetic models to reveal the genetic mechanism of these characteristics of zoysiagrass. The range of variation of each character in reciprocal progenies was far beyond that of their parents The widest variation was in inflorescence density, followed by the reproductive branch height, specule number of each spike, inflorescence length, specule length, and specule width. Significant differences were observed between two reciprocal crosses for inflorescence density, reproductive branch height, specule length, and specule length/width ratio, which further suggested that there might be maternal genetic phenomenon for these characters in zoysiagrass. There were no significant differences between two reciprocal crosses for inflorescence length, specule number of each spike, and specule width. The inflorescence density from the reciprocal cross Z136 ×Z039 was controlled by a two major gene model. A no major gene model （A-O） was the most suitable model for reproductive branch height, inflorescence length, and specule width of reciprocal crosses, specule number of each spike of negative crosses and the specule length of positive crosses. The specule number of each spike of positive crosses and the specule length of negative crosses of Z136×Z039 were controlled by a single major gene model. The most suitable model for the specule length/width ratio of positive crosses was a two additive-dominance-epistasis major genes model （B-l） and the heritability of major genes was 42. 72%0. A two additive-dominance major genes model （B-2） was the most suitable model for the specule length/width ratio of negative crosses and the heritability of major genes was 98.81%.