Development Of Molecular Marker Tightly Linked To The Taigu Genic Male Sterile Gene Ms2

Taigu Genic Male-Sterile Wheat (TGMSW) gene ms2 is the first dominant wheat nuclear male sterile gene found in Taigu in the world. Therefore, with great value of theory and practice, ms2 cloning is of great significance. The ms2 gene is located on the short arm of wheat chromosome 4D. But among the 21 chromosomes of wheat, the chromosome 4D has fewest polymorphisms on the published wheat genetic maps. So it brings much difficulty for map-based cloning ms2 from wheat. In Aibai wheat, Rht10 gene is tightly linked to ms2, no more than 0.18cM . The materials used in our experiment is Aibai-Chinese Spring near isogenic lines, having almost the same genetic background except RhtlO and ms2 regions and developed by using Chinese Spring to back cross with Aibai wheat for 12 times. Our study aims at finding the molecular marker tightly linked to ms2 and preparing for map-based cloning ms2 based on the previous work done by our lab.Firstly, a CAPS marker tightly linked to ms2 was developed based on the sequence information of BAC1J9 screened from Aibai BAC library using allele PCR marker located in RhtlO gene. CDS1 was one of the functional genes on BAC 1J9, which was about 90kb away from RhtlO and about 15kb in length. Ten pairs of primers were designed by analyzing the sequence of CDS1, and only one primers detected polymorphisms. Three SNPs were found between BAC 1J9 and Chinese Spring by sequencing the PCR products amplified with the primers. Based on the differences of restriction endonuclease Alw I sites induced by one SNP, a CAPS marker named MSCAPS-1 was developed. And after identified in the population of Aibai-Chinese Spring NILs and their recombinants, this CAPS marker was found to be tightly linked to ms2 and co-segregated with RhtlO.In the experiment, 12 mapped ESTs in wheat were also selected and analyzed to find the co-segregating marker with ms2 at the same time based on the co-linearity theory'between rice and wheat. These ESTs which are single copy and mapped on short arm of wheat chromosome 4D are homologous with the genes contained in rice BACs near BAC AC087797. After analyzed with the homologous genes in rice, 56 conservative primers were designed. And based on the sequences of D genome of Ae.tauschii and AB genome, D genome specific primers in common wheat were also designed. Using these specific primers and after sequencing the PCR products, the specific genome sequences alignments between Aibai and Chinese Spring were realized. Although no polymorphisms were detected between Aibai and Chinese Spring, it proves a feasible strategy to exclude the interference of heterogenous genomes in common wheat.