矮牵牛雄性不育“两用系”选育方法的研究

为了以最佳的选育途径育成新的矮牵牛雄性不育“两用系”。设计了2种选育途径获得新的矮牵牛雄性不育“两用系”，即连续自交保留不育株分离株系和在不育株分离株系系内兄妹交2种方法。比较两种方法在观赏性状的纯合效果，并对不同世代矮牵牛进行花径、花葶、株高的调查。结果表明BC2F2代系内兄妹交和连续自交的花径平均变异系数分别为8.26%和6.13%，BC3F2代系内兄妹交和连续自交的花径平均变异系数分别为4.20%和2.15%。随着世代的增加，自交的变异系数逐渐变小，基因型纯合速度更快。连续自交比系内兄妹交的变异系数小，连续自交是获得矮牵牛雄性不育“两用系”的最佳选育方法。发现优先模式，加快矮牵牛的F1代选育进程，为矮牵牛育种提供技术依据。

Study on Breeding Method of Genetic Male Sterile Line in Petunia hybrida Vilm

The aim was to select the best method of new male sterile line breeding,and then simplify and improve the breeding process.Two different methods,successive inbreeding to retain segregating strains of sterile plants and segregating strains of sterile plants by sib-mating,was used to obtain a new genetic male sterile lines.The homozygous effects of ornamental characteristics were compared among the two methods. Such characteristics as flower diameter,scape and height were investigated in different generations of Petunia hybrida Vilm.The average variation coefficients of BC2F2 generations produced by successive inbreeding and sib-mating were 8.26% and 6.13%,and that of BC3F2 generations were 4.20% and 2.15%,respectively.The variation coefficient of successive inbreeding dwindled and the purification of homozygous genotype was sped up by the increase of breeding generations.The variation coefficient of successive inbreeding was smaller than that of sib-mating,which suggested that successive inbreeding was the best method of breeding Petunia hybrida Vilm genetic male sterile line.Therefore,precedence mode had been found to speed up F 1 generation selecting process in Petunia hybrida Vilm as its breeding technical basis.