ABSTRACT
Mungbean Yellow Mosaic India Virus (MYMIV) is one of the most prevalent pathogen that limits soybean production in India. In this study RILs derived from JS335, dominant but MYMIV susceptible variety and PI171443, donor of MYMIV resistance gene in most of the MYMIV resistant varieties released in India and F2 population derived from SL525, a resistant variety released for northern India and NRC101, a susceptible genotype were used to study the inheritance of MYMIV resistance and map the gene responsible for MYMIV resistance. F1s were found to be completely susceptible. F2:3 and RILs population segregated to fit a ratio of 1:2:1 and 1:1 indicating that a single recessive gene controlled resistance to MYMIV. BSA was performed using 144 polymorphic SSR markers. MYMIV resistance gene was mapped on chr 6 (LG C2) within a 3.5-cM genome region between two SSR markers GMAC7L and Satt322 whose size was estimated to be 77.115 kb (position of 12,259,594-12,336,709 bp). This is the first report on linkage mapping of MYMIV resistance gene in soybean. This will be helpful in breeding soybean varieties for resistance against MYMIV responsible for wide spread damage to soybean crop in India using Marker Assisted Selection.
ABSTRACT
Mungbean yellow mosaic India virus (MYMIV) is a bipartite Geminivirus, which causes severe yield loss in soybean (Glycine max). Considering this, the present study was conducted to develop large-scale genome-wide single nucleotide polymorphism (SNP) markers and identify potential markers linked with known disease resistance loci for their effective use in genomics-assisted breeding to impart durable MYMIV tolerance. The whole-genome re-sequencing of MYMIV resistant cultivar 'UPSM-534' and susceptible Indian cultivar 'JS-335' was performed to identify high-quality SNPs and InDels (insertion and deletions). Approximately 234 and 255 million of 100-bp paired-end reads were generated from UPSM-534 and JS-335, respectively, which provided ~98% coverage of reference soybean genome. A total of 3083987 SNPs (1559556 in UPSM-534 and 1524431 in JS-335) and 562858 InDels (281958 in UPSM-534 and 280900 in JS-335) were identified. Of these, 1514 SNPs were found to be present in 564 candidate disease resistance genes. Among these, 829 non-synonymous and 671 synonymous SNPs were detected in 266 and 286 defence-related genes, respectively. Noteworthy, a non-synonymous SNP (in chromosome 18, named 18-1861613) at the 149th base-pair of LEUCINE-RICH REPEAT RECEPTOR-LIKE PROTEIN KINASE gene responsible for a G/C transversion [proline (CCC) to alanine(GCC)] was identified and validated in a set of 12 soybean cultivars. Taken together, the present study generated a large-scale genomic resource such as, SNPs and InDels at a genome-wide scale that will facilitate the dissection of various complex traits through construction of high-density linkage maps and fine mapping. In the present scenario, these markers can be effectively used to design high-density SNP arrays for their large-scale validation and high-throughput genotyping in diverse natural and mapping populations, which could accelerate genomics-assisted MYMIV disease resistance breeding in soybean.
