Galling pattern and host range studies of rice root-knot nematode (Meloidogyne graminicola)

Abstract

Studies were conducted on host range and galling pattern of M. graminicola seven different galling patterns with divergence from the typical hook like galls were observed that are clue for the existence of new species/races. In order to identify that host range studies were conducted it includes two trials tested under glasshouses condition. The test hosts involved ten varieties of rice viz., Biliya, Jyothi×Kesari, Akkalu, Jyothi, MO4, Tunga, KHP-2, JGL-1778, Kesari and Jyothi×Biliya and standard North Carolina test cultivars ie., tobacco cv. NC 95, cotton cv. Deltapine 16, peanut cv. Florunner, tomato cv. Rutgers and bhendi cv. Arka Anamika. All the tested cultivars used in the study were infected by M. graminicola, except cotton and bhendi no galls are observed on these cultivars. While, tomato (5.33), tobacco (12.40) and peanut (8.00) showed least galls on root system and least Rf value (0.035), (0.061) and (0.21) respectively. However, no galls were observed on cotton and bhendi and Rf value was nil. However, the North Carolina tomato cv. Rutgers showed galls on root system it is clearly showed that the North Carolina tomato cv. Rutgers is an experimental host for most of root-knot nematode, but not for the species that infect cereals, like. M. graminicola and M. graminis. Hence, it is an indication that existance of new species/races in this location that needs further confirmation.