Department of Nematology, Centre for Plant Protection Studies, Tamil Nadu Agricutltural University, Coimbatore-641 003, India
The life cycle of rice root-knot nematode, Meloidogyne graminicola was completed in 25–30 days in rice at 30 + 2°C. While screening of 52 popular rice varieties for resistance against M. graminicola, TKM 3, TKM 7, TKM 8, TKM 9 MDU 1, MDU 2, TKM 11 and PY 1 were rated as resistant. The defence enzymes viz., peroxidase, phenylalanine ammonia lyase, polyphenol oxidase activities; Phenol content was found to be higher in M. graminicola infested resistant rice varieties. The total and reducing sugar content were higher in M. graminicola infested susceptible varieties compared to resistant varieties. Marked differences were observed in the histopathology of roots of resistant and susceptible rice varieties following M. graminicola infestation. The larval migration in cortex and their establishment in stele occurred in two days in susceptible variety (TN 1) and 4 to 12 days in the resistant variety (TKM 9).
Root-knot nematode, rice, Meloidogyne graminicola, life cycle, histopathology, enzymes, phenols
