Sequence-tagged site-based diagnostic markers linked to a novel anthracnose resistance gene in chili pepper ( L.).

Anthracnose, caused by spp. is the most devastating disease of chili () in the tropical and subtropical regions of the world. The present study aimed at molecular mapping and development of markers linked to a new gene for anthracnose resistance in the chili cultivar 'Punjab Lal'. Phenotypic evaluation of F, F, and BCF populations derived from a cross between 'Punjab Lal' and susceptible cultivar 'Arka Lohit' against a virulent isolate of revealed that anthracnose resistance in Punjab Lal is governed by a monogenic-dominant gene designated as . Forty-four (28 ISSRs and 16 AFLPs) out of 201 markers exhibited parental polymorphism and were used in bulk segregant analysis. Three ISSRs (ISSR41, ISSR58, and ISSR112) and one AFLP marker (E-ACA/M-CTG) showed precise polymorphism between resistant and susceptible bulks, and were used for genotyping F and BC populations. The four putative fragments were converted into sequence-tagged site (STS) markers and southern blotting confirmed their association with the resistance locus. Molecular mapping revealed that the STS markers CtR-431 and CtR-594 were closely linked to the locus in coupling at distances of 1.8 and 2.3 cM, respectively. Furthermore, both of these markers showed the presence of resistance-linked allele in seven genotypes including the highly resistant 'PBC932' and 'PBC80' while negatively validated in 32 susceptible genotypes. Therefore, CtR431 and CtR-594 could be recommended as efficient diagnostic markers to facilitate the introgression of locus into susceptible chili variants towards the development of high-yielding anthracnose resistance genotypes in background.