CHARACTERIZATION OF MOLECULAR AND EPIDEMIOLOGICAL FACTORS IN RELATION TO RESISTANCE AGAINST MUNGBEAN YELLOW MOSAIC VIRUS DISEASE AND ITS MANAGEMENT

Abstract

Mungbean yellow mosaic virus (MYMV) is the most destructive virus which causes severe yield losses in mungbean and transmitted by whitefly. MYMV was present in the major mungbean cultivated areas of Punjab which greatly affect the mungbean production and is a major constraint in mungbean low yield. A mungbean germplasm collection consisting of 127 genotypes were screened against MYMV. Only three genotypes viz., NM2011, NM2006 and AZRI-06 showed resistance response during both years. Three lines 07007, 98001 and 014322 were identified with moderately resistance response against MYMV. These should be included in future breeding program. Results of molecular characterization showed that genotypes differ in their genetic makeup as well as in field response against MYMV. During RAPD analysis minimum similarity was shown for genotypes 8008 and Azri-06, while the maximum similarity was shown for genotype NM-54 with NM-92. In SSR analysis, minimum similarity was shown for genotypes 8008 and Azri-06, while the maximum similarity was shown by genotypes NM-54 and NM-92. SCAR markers linked with MYMV resistance gene produced the desired amplification in resistant and moderately resistant genotypes and no bands were observed in highly susceptible genotypes. Environmental factors were significantly correlated with disease development, maximum temperature, wind speed were negatively correlated with disease incidence and minimum temperature, relative humidity, rainfall, and whitefly population showed positive correlation with disease incidence. Regression analysis depicted that 83% of the disease variability was due to maximum, minimum temperatures, rainfall, relative humidity and wind speed. For the management of MYMV disease maximum control was achieved by use of imidacloprid, followed by combination of macro and micro nutrients (NPK, Fe,Zn,B), minimum control of disease was achieved by garlic. For the control of whitefly population, again imidacloprid gave the best results, followed by acetamiprid. The results of the present study could be used for future mungbean breeding program and genotypes that gave tolerant response could be recommended to farmers with application of imidacloprid followed by macro and micro nutrients in order to avoid the heavy losses caused by MYMV.