Occurrence of root-knot nematodes (Meloidogyne spp.) on peppers in Hainan, China, and resistance of field cultivars to M. enterolobii and M. incognita.

Abstract

Root-knot nematodes (Meloidogyne spp.) are the most economically damaging group of plant-parasitic nematodes. They are considered to be a major constraint of pepper (Capsicum annuum L) crops worldwide. In China, Hainan Island is the main producer of pepper, where the climatic conditions and cropping patterns are favorable for infection by Meloidogyne spp. In this study, we conducted a detailed investigation of the occurrence, severity and population distribution of root-knot nematodes infested pepper throughout Hainan Island. Meanwhile, we also tested the level of resistance to M. enterolobii and M. incognita for the field pepper cultivars in Hainan. Our results showed that root-knot nematodes belonging to M. enterolobii, M. incognita and M. javanica were found in Hainan, and the dominant population was M. enterolobii, which is the predominant species in the tropical area. Notably, all the pepper cultivars in this study were highly susceptible to M. enterolobii, which is probably one of the reasons for its rapid spread throughout Hainan. The pepper cultivars exhibited different levels of resistance to M. incognita. In conclusion, this study promotes the comprehensive understanding of the root-knot nematode distribution and host resistance level of Meloidogyne in Hainan, which will guide the effective control of root-knot nematodes.