Submitted to: Scienta Agricultra Scinica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/30/2001
Publication Date: 8/6/2001
Citation: Zhang, T., Yuan, Y., Guo, W., Yu, J., Kohel, R.J. 2001. SSR molecular tagging of QTLs for fiber strength in upland cotton. Scienta Agricultra Scinica. 34:363-366. Interpretive Summary: A Chinese Upland cotton line, 7235, produces good quality fiber. Two genes were identified for fiber strength in 7235 and simple sequence repeats (SSR) markers were developed to further analyze the genes. Chromosome locations of these two genes were determined from genetic analysis using a cross between 7235 and TM-1, another Upland cotton. The gene located on chromosome 10 had a very large genetic effect and its expression was very stable in different environments. The other gene was on chromosome 5 and its expression was unstable with a small genetic effect.
Technical Abstract: A G. anomalum introgression line, 7235, characterized as good fiber quality, developed in China, was used to identify SSR (simple sequence repeats) molecular markers linked to fiber strength QTLs. Three SSR molecular markers, NAU/SSR/fs1 130, NAU/SSR/fs2 190, and NAU/SSR/fs3 220 have been identified to be linked with high fiber strength QTLs. NAU/SSR/fs1 130 and NAU/SSR/fs2 190 were found to be closely linked with 2.3cM in genetic distance. The tagged QTL by these two SSR markers can explian 30.9% phenotypic variation of (7235 x TM-1)F 2. It is stably inherited over various environments and different years. Therefore, it is supposed that it is a major QTL responsible for high fiber strength in upland cotton. Another SSR marker, NAU/SSR/fs3 220, was linked to another QTL for fiber strength. However, its genetic effect is small and unstable. Monosomic tests indicated that the tagged QTL by NAU/SSR/fs1 130 and NAU/SSR/fs2 190 was mapped to chromosome 10 and another QTL by NAU/SSR/fs3 220 to chromosome 5.