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ARS Home » Midwest Area » Ames, Iowa » Corn Insects and Crop Genetics Research » Research » Publications at this Location » Publication #178964
Title: MOLECULAR MAPPING OF K2 MDHL1-N Y20, AN UNSTABLE CHROMOSOMAL REGION IN SOYBEAN [GLYCINE MAX (L.) MERR.]

Author
item XU, MIN - ISU
item Palmer, Reid

Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/22/2005
Publication Date: 11/7/2005
Citation: Xu, M., Palmer, R.G. 2005. Molecular mapping of k2 mdhl1-n y20, an unstable chromosomal region in soybean [Glycine max (l.) merr.]. Journal of Theoretical and Applied Genetics. 111:1457-1465.

Interpretive Summary: Some soybean plants are genetically unstable and can produce offspring with appearances (traits) different from their parents. We have identified three traits that came from genetically unstable plants. Two are easily observable, yellow leaves, and a saddle-pattern color (tan) on the seed coat. The other trait was a chemical trait (an enzyme), that can only be detected biochemically. Our objective was to study these three traits genetically. Our results indicate that these traits are associated together (physically) and tend to be transmitted from parent to offspring. Two of the traits have important economic considerations. The tan saddle seed are not acceptable in the commercial market. The yellow leaves result in plants that are small and have few seed. Plant breeders can select against these detrimental traits. The resulting selections will be better agronomic plants that will benefit the farmer and the consumer. However, these traits are important to understand the basic biology of the soybean plant.

Technical Abstract: In the soybean genome, a chromosomal region covering three tightly linked genes, k2, Mdh1-n, and y20, was found very unstable. It was suspected that the instability of the k2Mdh1-ny20 chromosomal region was caused by a non-autonomous transposable element residing adjacent to or in this region. In this study, we located and mapped this region with simple sequence repeat (SSR) markers on the soybean integrated map using five mapping populations. The k2 Mdh1-n y20 chromosomal region was located on molecular linkage group (MLG) H. The integrated map from five mapping populations consisted of 13 loci in the order Satt541, Satt469, Sat_122, Satt279, Satt253, Satt314, Mdh1-n, y20, k2, Satt302, Satt142, Satt181, and Satt434. The k2 Mdh1-n y20 chromosomal region was very close to Satt314, Satt253, and Satt279. The genetic distance between the Mdh1-n gene and Satt314 was less than 1 cM. The results of the mapping study were consistent with the results from previous studies that the Mdh1-n mutation in T261 (k2 Mdh1-n) and the Mdh1-n y20 mutation in T317 (Mdh1-n y20) were caused by deletions. In addition, another putative deletion was found in the genome of T261 which covered three SSR markers (Satt314, Satt253, and Satt279).