Field Screening of 44 Mungbean (Vigna radiata L.) Genotypes for Resistance to Mungbean Yellow Mosaic Virus (MYMV) under Natural Conditions in India

Abstract

Greengram (Vigna radiata L. Wilczek) is an important pulse crop in India, but its productivity is severely constrained by Mungbean Yellow Mosaic Virus (MYMV), a major biotic stress causing significant yield losses. The present study aimed to identify resistant sources among mungbean germplasm under natural field conditions. A total of 44 genotypes collected from diverse research institutes were evaluated during the Rabi season of 2020 at the Regional Agricultural Research Station, Warangal, using a Randomized Block Design with three replications. Disease incidence was recorded, and severity was assessed using a modified MULLaRP (0–9) scale where 0 to 2.0 score indicates resistance reaction. The results revealed considerable variation among genotypes in their response to MYMV. Thirteen genotypes exhibited resistant reaction, sixteen genotypes were categorized as moderately resistant, while thirteen were moderately susceptible and two were susceptible. Notably, IC-436528, MGG-389, IC-398952 exhibited the strongest resistance all showing score of only 0.4.  Typical MYMV symptoms included yellow mottling, chlorosis, stunted growth, reduced flowering, and malformed pods. The identified resistant genotypes can serve as valuable donor sources for breeding programs aimed at developing MYMV-resistant, high-yielding mungbean varieties, thereby contributing to enhanced pulse productivity and food security.