Evaluation of chilli genotypes and understanding biochemical basis of whitefly (Bemisia tabaci Genn.) resistance

Abstract

• Two resistant genotypes (IHR 4300 and IHR 4338) have been identified. • Cuticle thickness significantly negative correlated with adult survival, oviposition and nymphal population of whiteflies. • Higher concentration of phenolics and flavonoids are metabolic candidates for indirect selection of resistant genotypes. Whitefly is most devastating insect pest which causes damage by direct feeding on the host plant and also act as vector for transmission of many plant viruses causing severe yield losses in chilli. Host plant resistance is best advocated strategy in controlling the damage. We have screened the selected genotypes for white fly resistance using more accurate no-choice screening assays. Three types of assays i.e. clip-on-cage, detached branch and detached leaf methods of screening have been followed. Two resistant genotypes (IIHR 4300 and IIHR 4338) have been identified based on highest adult mortality, low oviposition rate, higher egg mortality and nymphal death. Cuticle thickness found significantly negative correlated with adult survival, oviposition and nymphal population. Semio-chemicals differing significantly amongst resistant and susceptible genotypes were identified through GC–MS and LC-MS and these can be used as metabolic candidates for indirect selection in screening genotypes/ populations for resistance. These two resistant chilli genotypes viz ., IIHR 4300 and IIHR 4338 can be explored for breeding for white fly resistance.