Research Projects

Common bean (Phaseolus vulgaris L.) is widely cultivated and consumed legume of the genus Phaseolus throughout the world. India ranks second in the dry beans production (Nadiem et al., 2021). Among the various diseases infecting beans, anthracnose caused by the fungus Colletotrichum lindemuthianum is top most important fungal disease in the region. Many anthracnose resistance genes have been fine mapped in the USA, Canada and France. In contrary, only resistant sources against different races have been identified in India. Among these resistant sources, common bean landrace KRC-5 has shown stable resistance to 17 anthracnose races over a period of three decades (Kumar et al., 1997; Sharma et al., 1999 Sharma et al., 2012, Katoch et al., 2019). Preliminary genetic studies performed by Sharma et al., 2000 reported a major anthracnose resistance in KRC-5 against bean anthracnose race 903. We reconfirmed inheritance pattern of anthracnose resistance in KRC-5 (Pathania et al., 2006) that indicated KRC-5 carries a single dominant resistance gene against race 775 also. We mapped the resistance-governing gene in KRC5 to race 3 and 211 using an F2:3 population. Out of a panel of 287 RAPDs, we identified two RAPD markers co-segregating with resistance. Since RAPD markers are not reliable, so we eluted the target bands and sequenced the region. We then developed two SCAR markers (SCOPR15 and SCOPF6) and used these to map resistance gene in KRC-5. The data analysis revealed that the R gene is flanked by SCARs at a distance of 4.6cM. The sequence of these two SCAR markers upon blast on phytozome revealed two hits on novel genomic region of Pv10 between physical positions of 0.6 to 4.8Mb indicating that the anthracnose resistance gene lies between these physical positions. The 25 major anthracnose resistance genes have previously been mapped to 07 chromosomes except Chromosome 5, 6, 9, and 10 (Banoo et al., 2020; Nabi et al., 2022). These results indicate that the anthracnose resistance gene in KRC-5 is novel and we named it as Co-Ind. We then developed SSR/InDel markers within this genomic position and the closet indel and SSR markers are approximately 1.68cM away from the Co-Ind gene. There is a cluster of genes (47 genes) encoding NB-ARC within the span of 3.20 to 4.38 Mb. In present grant proposal, we will fine map the Co-Ind gene using a bi-parental RIL population (Jawala x KRC5). The molecular basis of Co-Ind resistance will be performed by long-range PCR amplification of fragments to carry out the detailed functional analysis of target Co-Ind region. RNASeq between two contrasting RIL lines will also be performed to understand the elicitation of resistance. Fine mapping of Co-Ind gene will help in delineating the target region with few candidate genes. Sequence analysis, RNASeq and transient expression of candidate gene(s) within the target region of Co-Ind will provide the insights on molecular mechanism of gene for gene interaction.