Research Papers: Reactions of Some Rice Cultivars to the Root-Knot Nematode, Meloidogyne incognita


  • J. D. Babatola


Oryza sativa, Plant Breeding, Nematode Control


In a survey of nematodes affecting rice, the root-knot nematode, Meloidogyne incognita was found to occur in all the surveyed upland rice growing areas of Southern Nigeria. Forty-four rice cultivars were screened for resistance to M. incognita in a glasshouse with a temperature range of 15-35C and also in the field. The reactions of the cultivars varied from very susceptible to resistant based on the proportion of the total root system galled. Single terminal galls were always found on rice roots, but occasionally multiple galls occurred along the roots. Lateral roots were also galled terminally. Such terminal galling prevented further growth of the roots, and often rot organisms caused decay of older, galled roots. Infected susceptible rice plants manifested general chlorosis, poor tillering and sometimes wilting which led to eventual death. Resistant cultivars Vars 13a/103/F 2591/5/3, IR 20 and Var 54/6/6/6 had very few and small galls and necrotic lesions close to the growing poin