Assessment of root-knot nematode, M. incognita and identification of the source of resistance in cauliflower, Brassica oleracea

Abstract: Root-knot nematodes of genus Meloidogyne are the most devastating plant parasitic nematodes of vegetable crops responsible for severe global economic losses. The objective of the present work was to study the diversity of Meloidogne species in cauliflower growing areas of Punjab and to identify the source of resistance against M. incognita. The root and soil samples were collected from the cauliflower growing areas and associated nematode specie(s) was identified based on perineal pattern morphology and morphometry of adult females. M. incognita sp. was found most prevalent in all the cauliflower growing areas surveyed. A total of thirty genotypes of Cauliflower (Brassica oleracea) was screened against root-knot nematode, M. incognita, in pots. Four genotypes viz., LSMVAR-6, PI1654, LSMVAR-2 and LS-4 were resistant to M. incognita with root galling index (RGI) less than 2.0 and reproduction factor (Rf) less than 1.0. Among others, fourteen genotypes showed hypersusceptible (RGI 2.0- 2.6; Rf 0.57-1.0) and eleven genotypes showed a susceptible reaction. The resistant genotypes identified in the present study may be utilized to incorporate resistance against M. incognita in commercial cauliflower cultivars.