The genetic base of establishing stable ms lines by means of improving Pol cms line in Brassica napus L.

摘要

The genetic characters of three RG ms two-used lines Xiangyou402AB, 104AB and 127AB, and four TG ms lines Xiangyou402S, 022S, 104S and 1030RS have been studied. The results united with the previous studies on the inheritance of 104AB and 104S show that the ms genes from Xiangyou402A, 104A and 127A are not allele between each other, and Xiangyou402A and 127A have two couples of ms genes respectively, and 104A has a couple of ms gene. Among four TG ms lines, Xiangyou402S, 022S and 1030RS have the same two couples of ms genes and a couple of mainly effective thermo-sensitive genes modified by some minim quantity genes all from Xiangyou91S, while 104S has a couple of ms genes and a couple of mainly effective thermo-sensitive genes modified by some minim quantity genes which are not the allele with that from the former three TG ms lines. Between RG and TG ms lines, Xiangyou402A has the allelic ms genes from Xiangyou402S, 022S and 1030RS, but the ms genes of 127A is not allelic with that of 022S, and 104A has the allelic ms genes from 104S. The results also show the thermo-sensitive genes from several TG ms lines have not allelic relationship with that from Pol cms line Z04A or its maintainer Z04B. Furthermore, all thermo-sensitive genes from different sources can just regulate the corresponding ms genes or sterile cytoplasm but can not regulate other ms genes. Six ms groups have been got by means of improving Z04A using the fertile plants of three RG ms lines and three TG ms lines as the back-crossing parents, among which one group has about 75% partially sterile plants and about 25% completely sterile plants, and two groups have about 50% partially sterile plants and 50% completely sterile plants, and two groups have 100% completely sterile plants and one group has 100% partially sterile plants that has been bred using TG ms line with restoring gene Rf. The genotypes of above ms lines and the gained ms groups are deduced, and a "circular regulation mode" is put forward to explain the genetic mechanism of establishing stable cms lines without trace-pollen at the state of different thermo-sensitive genes existing.