2.2.98
VARIABILITY IN ISOLATES OF MACROPHOMINA PHASEOLINA CAUSING ROOT ROT IN MUNG BEAN IN TAMIL NADU, INDIA

EG EBENEZAR, M MUTHUSAMY and K SEETHARAMAN

Department of Plant Pathology, Agricultural College and Research Institute, Madurai 625104, India

Background and objectives
Root rot caused by Macrophomina phaseolina is a serious disease in mung bean. Losses of up to 60% have been estimated due to this disease [1]. Experiments were conducted to study the variability of the root -rot causing pathogen.

Materials and methods
Variation in growth pattern, sclerotial size and virulence were observed [2]. Nine isolates of the pathogen were collected from different mung bean tracts of Tamil Nadu in India.

Results and conclusions
The nine pathogenic isolates exhibited significant differences in their virulence and cultural characters. The isolates of the pathogen produced cottony white or dull white mycelia. Madurai isolates showed the maximum virulence, and produced larger-sized sclerotia and pycnidiospores than the other isolates.

References
1. Deshkar MV, Khare MN, Singh L, 1974. JNKVV Research Journal 8, 60-62.
2. Rant JG , Angle RW, 1989. Indian Phytopathology 42, 506-508.