Resistance to Bemisia tabaci Asia I in Capsicum Reduces Whitefly Performance and Is Associated With Lower Pepper Yellow Leaf Curl Virus (PepYLCV) Disease

Abstract

The widespread development of insecticide resistance and stricter regulations on pesticide use highlight the need for natural pest resistance in crops. In pepper, viral diseases such as pepper yellow leaf curl virus (PepYLCV), transmitted by the whitefly Bemisia tabaci , are a major constraint in tropical regions. In this study, we explored genetic variation within Capsicum spp. to identify sources of resistance against B. tabaci Asia I and assessed whether plant resistance is associated with reduced PepYLCV disease. Eleven accessions were screened in no‐choice and choice assays using viruliferous and nonviruliferous whiteflies for host acceptance, survival, oviposition and development and evaluated for disease symptoms and PepYLCV presence under semi‐natural field infestation. Plant accession was the main factor determining whitefly performance. Capsicum annuum CA9, previously identified as resistant to B. tabaci MEAM1, was among the least preferred by whitefly adults and was associated with low population growth of B. tabaci Asia I. Several other accessions, including CA6 and CA8, and Capsicum chinense CC35, also showed reduced whitefly performance relative to susceptible accessions although the magnitude varied across assays and treatments. Differences between whitefly treatments were secondary and species dependent: Adult emergence was higher with viruliferous whiteflies on all C. annuum accessions but higher with nonviruliferous whiteflies on all C. chinense accessions, supported by a significant species × treatment interaction. Because the two whitefly treatments also differed in age and feeding history, these differences are interpreted as between‐treatment effects rather than effects of the virus itself. In the field, CA9 and several other accessions, notably CC35, remained at very low disease incidence. Overall, we identify promising candidate genetic resources for breeding pepper with reduced susceptibility to B. tabaci and lower associated disease, although the present field design cannot separate reduced vector performance from direct effects on the virus, which should be further studied.