Exploring host plant resistance in chilli (Capsicum spp) against Southeast Asian thrips (Thripsparvispinus Karny)

Abstract

Southeast Asian thrips (Thrips parvispinus Karny), poses a significant threat to chilli crop production causing severe economic losses. They feed heavily on leaves, flowers and young fruits causing severe damage to the crop. Exploring host plant resistance is the best ecofriendly management strategy to combat this pest. Large-scale field screening of 481 germplasm accessions, followed by further screening of selected accessions under polyhouse conditions led to identification of fourteen accessions that showed resistance against Southeast Asian thrips. Among the screened accessions, IIHR-B-HP-79 showed the highest level of Southeast Asian thrips resistance with significantly low leaf and fruit damage scores of 0.28 and 0.13, respectively. Further, screening of selected fourteen field resistant accessions was performed through whole plant bio-assay where in four accessions i.e., IIHR-B-HP-79 (C. frutescens), IIHR 4550, IIHR 4501 & IIHR 4410 (C. chinense) showed good level of resistance. Multi-choice leaf disc assay, demonstrated that IIHR-B-HP-79 exhibited a high level of resistance with the lowest percent of scraping damage during both the vegetative (10.98) and flowering stages (15.31). The identified resistant accession IIHR-B-HP-79 (C. frutescens), has the potential to be a valuable genetic resource as donor in breeding for Southeast Asian thrips resistance.