Submitted to: Theoretical and Applied Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/23/2006
Publication Date: 4/14/2006
Citation: Chen, J., Hu, J., Vick, B.A., Jan, C.C. 2006. Molecular mapping of a nuclear male-sterility gene in sunflower (Helianthus annuus L.) using TRAP and SSR markers. Theoretical and Applied Genetics. 113:122-127. Interpretive Summary: Nuclear male sterility (NMS) in sunflower (Helianthus annuus L.) provides specific tool in sunflower breeding, and 11 of them have gene symbols assigned as ms1 through ms10. Molecular marker technology provides the opportunity to map a gene of agronomic importance to linkage groups, and tightly linked markers can be used to aid early identification and selection of NMS plants in seedling stages. This study demonstrated the effective approach of using a newly developed TRAP technique and more established SSR techniques to identify a set of TRAP markers flanking the ms9 locus and reported the mapping of the ms9 gene to sunflower linkage map constructed using SSR markers. This information will facilitate the transfer of the ms9 allele in sunflower breeding programs through the use of markers tightly linked to ms9, and will help future isolation of the ms9 gene by map-based cloning.
Technical Abstract: A nuclear male-sterile mutant, NMS 360, possesses a single recessive gene, ms9, controlling male sterility. The present study identified DNA markers linked to the ms9 gene in an F2 population derived from the cross of NMS 360 x RHA 271 and maps the ms9 gene to an existing sunflower SSR linkage map. Bulked segregant analysis was performed using the target region amplification polymorphism (TRAP) technique and the simple sequence repeats (SSR) technique. From 444 primer pairs, six TRAP markers were linked with the ms9 gene. Two markers, Ts4p03-202 and Tt3p09-529, cosegregated with the ms9 gene. The other four markers, To3d14-310, Tt3p17-390, Ts4p23-300 and Tt3p09-531, linked with ms9 at a distance of 1.2 cM, 3.7 cM, 10.3 cM and 22.3 cM, respectively. Thirty SSR primers from 17 linkage groups of a PHA x PHB cultivated sunflower linkage map were screened among the two parents and the F2 population. SSR primer ORS 705 of linkage group 10 was tightly linked to ms9 at a distance of 1.2 cM. The ms9 gene was subsequently mapped to linkage group 10 of the PHA x PHB SSR linkage map. The markers that were tightly linked with the ms9 gene will be useful in marker-assisted selection of male-sterile plants among segregating populations, and will facilitate the isolation of the ms9 gene by map-based cloning.