LCVD resistance breeding in heat tolerant bell pepper: Combined phenotypic and marker-assisted backcrossing for introgression of LCVD resistance from hot pepper

Hot pepper ( Capsicum annuum var. annuum ) and bell pepper ( C. annuum var. grossum ) are the important crops of the Solanaceae family. In the present study, marker-assisted selection (MAS) was employed for interspecific leaf curl virus disease (LCVD) resistant gene introgression from hot pepper (S-343) to heat-tolerant bell pepper lines. Segregating populations were developed using resistant (S-343) and susceptible (bell pepper) genotypes for understanding the genetics of LCVD resistance. The micro-cage artificial screening technique was used for the phenotypic selection of LCVD resistant plants from progenies of each population. The F 1 of all crosses were resistant to LCVD, while F 2 and BC 1 F 2 generations of all the crosses were segregated into 3:1 (resistant:susceptible) and BC 1 F 1 generations of all crosses were a good fit to ratio 1:1 (resistant:susceptible) suggesting monogenic dominant control of LCVD resistance. In addition to phenotypic selection for LCVD resistance, MAS for non-pungency was done using ‘BF7’ and ‘BR9’-SCAR primers along with the very stringent phenotyping (background selection) in backcrossed populations for most important fruit traits. The background selection was performed for the recovery of recurrent parent phenome and it was measured as shift in means of these important fruit traits. To the best of our knowledge, it is a novel experiment of introgression of LCVD resistance in heat tolerant bell pepper lines that led to the successful development of six improved LCVD resistant, heat-tolerant and non-pungent BC 2 F 1 populations (LCVRS3SM-1, LCVRS3SM-2, LCVRS3SM-8, LCVRS3SM-4, LCVRS3SM-17, and LCVRS3SM-58) that will help in future bell pepper resistant breeding programs.