STUDIES ON ACTIVE CHANGES IN DEFENSE RELATED ENZYMES IN PEPPER RESPONSES TO HELICOTYLENCHUS MULTICINCTUM AND MELOIDOGYNE INCOGNITA INFECTIONS

Abstract

An experiment was conducted at the screen house of Niger State College of Agriculture, Mokwa to evaluated nine accessions and a variety of pepper Capsicum species for changes in activities of phenolic compounds accumulation in relation to resistance or susceptibility to combined parasitism of Helicotylenchus multicinctum and Meloidogyne incognita. The trial was laid out using completely randomized design with three replications. Each of the accessions and the variety was inoculated with approximately 2000 mixed population, 1000 each of H. multicinctum and M. incognita on the root and adhering soil. Root samples were collected a day before inoculation and at day 7, 14 and 21 post inoculation. Standard methods were employed to quantified phenolic content and tannins. Changes of pepper phenolic contents on total antioxidant capacity of peroxidase, polyphenol oxidase and tannins on their response to H. multicinctum and M. incognita infection were recorded. In comparison, extracts from the roots of five pepper accessions viz NGB00581, NGB00587, NGB00629, NGB00684 and NGB00574 had high concentrations of peroxidase, polyphenol oxidase and tannins as compared to the remaining varieties tested, indicating the strong level of their responses to combined H. multicinctum and M. incognita attack. Findings from this study suggest the potential of pepper phenolics in reducing nematode infection in pepper production. The result of the present study shows that five of the ten pepper accession/variety possess high quantities of natural antioxidants and can be further investigated for possible use in the management of pepper nematode infections.