Metabolite profile variation of chili pepper genotypes for resistance to aphids infestation

Abstract

The cotton aphids (CA) were reported to reduce chili pepper production in tropical area and transmits several viruses. Using resistant cultivars can reduce the number of insecticide sprays and maintain natural enemies. The research objective was to evaluate aphid infestation in seven chili pepper genotypes and investigate secondary metabolite profiles under aphid infestation. Seven chili pepper genotypes belonging to the species Capsicum annuum L. were used in this study. The experiment was conducted using a four-replication randomized complete block design. We used a no-choice clip cage test to evaluate the chili pepper genotype. The evaluation was carried out under greenhouse conditions. Each plant was infested with one aphid using a wet brush in an insect-proof cage about five weeks after sowing. The resistance level was determined after seven days of infection (7 DAI) by counting the number of aphids. Gas chromatography-mass spectrophotometry (GC-MS) was used to perform untargeted metabolomic studies. The results showed that IPB C20 and IPB C367 genotypes had low aphid infestation, while IPB C313 showed the highest aphid infestation. Untargeted metabolomics using GC-MS detected 16 metabolites in the control plant and 27 in the treatment. Principal component analysis (PCA) (PC1 = 62% and PC2 = 23%) can used to differentiate metabolites among resistant genotypes, susceptible genotypes, and control plants. Chili pepper resistance to aphid infestation was antibiosis with numerous potential metabolite chemicals, such as fluorobenzoic acid, which strongly connected with decreased aphid colonies at 7 DAI. This study will be useful for pest control and will aid in the developing of aphid-resistant cultivars.