|Klos, K - IOWA STATE UNIVERSITY|
|Paz, M - IOWA STATE UNIVERSITY|
|Marek, L - IOWA STATE UNIVERSITY|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 19, 1999
Publication Date: N/A
Interpretive Summary: The soybean disease, Brown stem Rot, results in a loss of production of over 20 million bushels each year in the North Central States alone. Genes for resistance to this disease are present in some soybean lines. However, selecting for resistance is expensive and time consuming. Molecular markers tightly linked to the resistance genes would make selection faster, cheaper rand more efficient. The authors developed nine markers which can predict resistance among progeny of a segregating population with an accuracy of 91-98%. These markers will allow breeders to incorporate Brown Stem Rot resistance into high yielding cultivars faster and cheaper than before. This will result in higher soybean yields and more stable production.
Technical Abstract: Brown stem rot (BSR) causes vascular and foliar damage in soybean. Identification of plants resistant to BSR by inoculation with Phialophora gregata is laborious and unreliable due to low heritability. Molecular markers linked to the resistance gene could be used to screen for resistant individuals and hasten the development of BSR resistant genotypes. The objective of this study was to develop molecular markers for efficient identification of BSR resistant plants in a breeding program. DNA markers were developed that tag the BSR locus and are informative in a diverse range of soybean germplasm. Seventeen resistant and twenty-nine susceptible cultivars and plant introductions as well as recombinant inbred lines derived from a cross between BSR 101 and PI 437.654 were assayed using PCR-based markers derived from RFLPs K375I-1 and RGA2V-1, Satt244, or developed from bacterial artificial chromosome (BAC) sequences. Markers detected different banding patterns between resistant and susceptible genotypes. PCR-based Gm_ISp_BSR3.sp1, Gm_ISp_K375.sp1, Gm_ISb001_014_H13.sp1, Gm_ISb001_021_E22.sp1, Gm_ISb001_021_E22.sp2, Gm_ISb001_030_L19.sp1, Gm_ISb001_035_E22.sp1, Gm_ISb001_098_P22.sp2, and Satt244 markers will most likely be useful in screening for BSR resistance and allow plant breeders to facilitate the rapid transfer of resistance derived from Rbs3 to improved cultivars or soybean lines. The markers are easy-to-use, inexpensive, and highly informative. Based on this information, soybean breeding efforts can now be designed to utilize parental genotypes possessing contrasting banding patterns.