Submitted to: Journal of Heredity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/9/2007
Publication Date: N/A
Citation: Interpretive Summary: Purple seed stain is a fungal disease of soybean where infection of the seed results in purple discoloration due to the fungal toxin cercosporin. Economic losses due to purple seed stain have been estimated at 25.25 metric tons. Current strategies to control this disease are not completely effective and little is known about genes within the host that could provide resistance. Based on our lack of resistance knowledge, scientist from the United States Department of Agriculture-Agricultural Research Service in Aberdeen, ID and the University of Arkansas, Fayetteville, AR sought to identify soybean genes that provide resistance to this damaging disease. In their work they discovered the location of a gene providing resistance and identified genetic markers to accelerate the production of new soybean lines with the resistance gene. Currently, work is being done by the University of Arkansas’ soybean breeding program to develop new soybean cultivars with the new gene.
Technical Abstract: Purple seed stain (PSS) of soybean caused by Cercospora kikuchii is an important disease that reduces market grade and can affect seed germination and vigor. A single dominant gene was shown to confer PSS resistance in PI 80837. The objective of this research was to map the PSS resistance gene in PI 80837 using simple sequence repeat (SSR) markers. A cross was made between the PSS-susceptible cultivar Agripro 350 (AP 350) and PI 80837. The F2 population and parents were grown in the field and the resistance or susceptibility of individual plants was determined by assaying seed for infection by C. kikuchii. DNA of parent and F2 plants was extracted for SSR analysis and mapping. Segregation ratios for seed infection and for SSR markers showed that a single dominant gene conditions resistance to PSS in PI 80837. The candidate resistance gene was mapped between Sat_308 (6.6 cM) and Satt594 (11.6 cM) on molecular linkage group (MLG) G. These markers may be useful in marker-assisted selection for utilizing PSS resistance from PI 80837 in a breeding program.