Modulation in certain biochemical constituents of cashew as influenced by tea mosquito bug Helopeltis antonii

Abstract

The tea mosquito bug (TMB) Helopeltis antonii Signoret is a major constraint in cashew cultivation. Exploring host plant resistance will open up new avenues to manage this. The present study is the on biochemical changes occurring in four cashew varieties belonging to highly susceptible and less susceptible categories towards tea mosquito bug. The results reveal that total leaf protein was found to be more in the less susceptible variety Damodar (0.9925 mg g−1) and the least with the highly susceptible Madakkathara-1 (0.6729 mg g−1). Likewise, the total phenol and tannin were more in the less susceptible Damodar (69.834 mg g−1 and 4.276 mg g−1, respectively) and Raghav (67.207 mg g−1 and 4.420 mg g−1, respectively); with the least values being in the highly susceptible Anagha and Madakkathara-1. The activity of polyphenol oxidase was more in Damodar (0.003158 EU g−1min−1) and the least with Anagha (0.001406 EU g−1min−1). These observations on the biochemical changes conclude that there is significant variation in the infestation reactions of TMB in the highly susceptible and less susceptible cashew varieties. Also, the defensive molecules such as tannin, phenols and the defensive enzymes like polyphenol oxidase and phenyl alanine lyase were more in the less susceptible varieties Damodar and Raghav.