|WANG, XUEYAN - University Of Arkansas|
|GHAI, POOJA - Arkansas State University|
|LEE, FLEET - University Of Arkansas|
Submitted to: Molecular Plant-Microbe Interactions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/4/2015
Publication Date: 12/16/2015
Citation: Wang, X., Jia, M.H., Ghai, P., Lee, F.N., Jia, Y. 2015. Genome-wide association of rice blast disease resistance and yield-related components of rice. Molecular Plant-Microbe Interactions. 28(12):1383-1392. doi.org/10.1094/MPMI-06-15-0131-R.
Interpretive Summary: Resistance to rice blast disease (Magnaporthe oryzae) could result in poor yield production if the resistance response requires expenditure of energy by the plant. In the present study, we genotyped a selected set of 151 diverse rice accessions with 156 molecular makers and performed a genome wide association analysis to relate the presence of genetic markers to 12 common races of the blast fungus found in the Southern U.S. and to yield related traits including plant height, heading date, and seed weight. We found that the molecular markers associated with blast resistance were also associated with yield related traits. The physical intervals between some markers were less than 5 megabases on the rice chromosomes. Most noticeable, taller plants were correlated with blast susceptibility, and rice germplasm carrying the major blast resistance gene Pi-ta were associated with lower seed weights. These findings are useful for developing strategies for combining high yield and blast resistant in new rice cultivars via genomic and marker assisted selection.
Technical Abstract: Robust disease resistance may require an expenditure of energy that may limit crop yield potential. In the present study, a subset of a USDA rice core collection consisting of 151 accessions was selected using a major blast resistance (R) gene Pi-ta marker, and was genotyped with 156 simple sequence repeat (SSR) markers. Disease reactions to Magnaporthe oryzae, the causal agent of rice blast disease, were evaluated under greenhouse and field conditions, and heading date, plant height, paddy and brown seed weight in two field environments were analyzed using an association mapping approach. Twenty-one SSR markers distributed among rice chromosomes 2 to 12 were associated with blast resistance, and 16 SSR markers associated with seed weight, heading date, and plant height. Most noticeably, shorter plants were significantly correlated with resistance to blast; rice germplasm with Pi-ta were associated with lighter seed weights; the susceptible alleles of RM171 and RM6544 were associated with heavier seed weight. These findings unraveled a complex relationship between disease resistance and yield related components.