Unravelling Phenotypic and Molecular Determinants of Resistance to Whitefly ( Bemisia tabaci ) in Bell Pepper ( Capsicum annuum L.)
Abstract
The whitefly, Bemisia tabaci (Gennadius), is a destructive pest of bell pepper, leading to substantial yield losses through direct feeding and transmission of viral diseases. In view of the limitations of chemical control, host plant resistance has emerged as a sustainable and environmentally safe approach for effective management of whitefly infestation. This study presents a comprehensive phenotypic and molecular evaluation of bell pepper genotypes for resistance against B. tabaci . A total of 57 bell pepper genotypes were screened under field conditions during the kharif seasons of 2023–2024 and 2024–2025 using a randomised block design with three replications of each genotype at the experimental farm of the Department of Entomology, Dr. Y.S. Parmar University of Horticulture and Forestry, Nauni, Solan (HP) to identify resistant sources. Field screening revealed that bell pepper genotypes IIHR‐138 and UHF‐CAP‐114 recorded the lowest mean whitefly count of 0.18 and 0.24 per three leaves, respectively. Among the various morphological and biochemical parameters, the correlation analysis revealed that B. tabaci population exhibited statistically significant ( p ≤ 0.05) positive correlation with non‐glandular trichomes, percent leaf curl and sugar content, whereas statistically significant ( p ≤ 0.05) negative correlation was observed with glandular trichomes, cuticle thickness, plant height, plant spread, chlorophyll content, fruit yield per plant, phenol, flavonoids, tannin, phenylalanine ammonia lyase, peroxidase and polyphenol oxidase. The molecular characterisation with RAPD, ISSR and SSR markers effectively discriminated resistant and susceptible genotypes, with SSR markers exhibiting the highest polymorphism and consistently clustering highly resistant lines, indicating a stable genetic background for whitefly resistance. Hence, the identified resistant bell pepper genotypes, IIHR‐138 and UHF‐CAP‐114, may serve as reliable donor parents for developing whitefly‐resistant varieties.