|Identification of genomic variants of rice associated with disease resistance to sheath blight and bacterial panicle blight through NGS sequencing |
B. K. Shrestha (1), D. H. Oh (2), M. Dassanayake (3), J. H. HAM (1). (1) Louisiana State Univ Agric Ctr, Baton Rouge, LA, U.S.A.; (2) Louisiana State University, Baton Rouge, LA, U.S.A.; (3) Louisiana State University, Baton Rouge , LA, U.S.A.
Sheath blight and bacterial panicle blight cause severe yield reductions of rice in many rice-growing regions around the world. Vertical resistance has not been found for these rice diseases, unlike blast or bacterial leaf blight, and only a few rice cultivars and lines show certain levels of quantitative resistance to these diseases. Jupiter, a medium-grain cultivar, and LM-1, a mutant line derived from the disease-susceptible cultivar Lemont, have been shown high levels of quantitative resistance to sheath blight and bacterial panicle blight and used as genetic resources for breeding of disease-resistant rice in LSU AgCenter. For better understanding of the genetic backgrounds related to the quantitative disease resistance to these major rice diseases, the whole genomes of Jupiter and LM-1 were resequenced along with those of Trenasse (disease-susceptible long-grain cultivar), Bengal (disease-susceptible medium-grain cultivar) and Lemont (the disease-susceptible parental line of LM-1), using an Illumina platform. Analyses of the draft sequences revealed DNA polymorphisms including synonymous and non-synonymous single nucleotide polymorphisms and small insertions and deletions among the five rice genotypes as well as the known or putative biological functions of polymorphic rice coding sequences. This information greatly contributes to our ongoing genetic/genomic study of rice disease resistance and breeding program to develop new disease-resistant rice cultivars.