Breeding Of Male Sterility Lines And Their Homologous Maintainers Of Huyoul5and303A By Marker-assisted Selection In Rapeseed(Brassica Napus L.)

Rapeseed is one of the world’s most important oil crops, and the superiority of heterosis is an important means of improving quality of rapeseed. Backcrossing breeding is an effective way of improved individual traits of varieties, but it has a long breeding life time. Dopting the method of molecular marker-assisted combination with backcross breeding, can rapid positioning the target gene, which can achieve the purpose of improving varieties and shortening the breeding life time.In this research subject we use a recessive genic male sterility (RGMS) of9012A which controlled by two pairs of genes. We use a three-lines RGMS system and no need to require for removing50%fertile plants in the maternal line hybrid seed production, obtaining100%sterile plant by temporary maintain lines (TAM), saving the cost of the breeding. It is extremely important and difficult to gain the homozygous male sterility lines and TAM with same genetic background, while marker-assisted selection in combination with backcrossing breeding sehedules is expected to get them in3-4generations.Our research took the9012A as the donor of male sterility gene and took the HY15and303A as recurrent parent to select homozygous two-type and TAM with the marker-assisted selection technique.The main results are summarized as follows:1Breeding of homozygous two-type line and its maintainer of huyou151) The AFLP technique was used to analyze the background of the122sterile plants of the F2population (9012A×HY15). Five plants with the most similar genetic background as HY15were backcrossed with HY15to get F2BC2;2) The marker WSC1was used to find out101genotypes of Ms3ms3RfbRfc in the total of257individuals of F2BC1Three target individuals with the most similar genetic background of the recurrent parent backcrossed with HY15for getting F2BC2;3) Three plants genotypes of Ms3ms3RfbRfc and the genetic background similar with HY15in the the F2BC2population of144plants and were selected out after both the foreground selection with the markers linked to Ms3or Rf and the background selection with SSR markers, being backcrossed with HY15for getting F2BC3;4)39plants genotypes of Ms3ms3RfbRfc in the F2BC3population were selected out by the markers linked to Ms3/ms3or Rf. The39plants were selfed to get F2BC3F2; 5) Through foreground selection in the total518individuals of F2BC3F2population,45fertile plants(Ms3ms3RfbRfb),26homozygous sterile plants(ms3ms3RfbRfb) and29maintainer plants(ms3ms3RfbRfb) were selected out.2Breeding of homozygous two-type line and its maintainer of303A1) The AFLP technique was used to analyze the background of the139sterile plants of the F2population (9012A×303A). The number of6Y77with the most similar genetic background as303A were backcrossed with303A to get F2BC1;2) The marker WSC1was used to find out96genotypes ofs3ms3RfbRfc in the total of188individuals of303A F2BC1. Three tkarget individuals with the most similar genetic background of the recurrent parent. The3individuals of303A were selfed to get F2BC1F2;3) Five plants were selected out by background selection with SSR markers in the total46sterile plants of303A population, being backcrossed with303A for getting F2BC1F2BC1(F2BC2);4)46plants genotypes of Ms3ms3RfbRfc in the F2BC2F2population were both selected out by the markers linked to Ms3/ms3or Rf were selfed to get F2BC2F3;5) Through foreground selection in the total422individuals of F2BC2F3population of303A,45fertile plants (Ms3ms3RfbRfb),19homozygous sterile plants(ms3ms3RfbRfb) and21maintainer plants(ms3ms3RfbRfb) were selected out.