Identification of MYMV resistant and photo-thermo insensitive lines in mungbean

Abstract

Production and productivity of mungbean [Vigna radiata (L.) Wilczek], a self-pollinated crop grown in different seasons i.e. Kharif, Rabi and Zaid in India, is adversely affected by low (<15ºC) and high (>40ºC) temperature regimes as well as susceptibility to prevalent diseases (mungbean yellow mosaic, cercospora leaf spot and powdery mildew). This hampers the horizontal expansion of crops in diverse agroclimatic regions. However, ricebean [Vigna umbellata (Thunb.) Ohwi & Ohashi] represents useful reservoir of disease resistance genes as well as source of photo-thermo insensitivity. Five genotypes of ricebean viz., RBL 1, RBL 6, RBL 9, RBL 35 and RBL 50 were evaluated for photo-thermo insensitivity and resistance to yellow mosaic disease. Out of the five ricebean genotypes evaluated, RBL 9 had shown substantial amount of photo-thermo insensitivity as it flowered and set pods at both high (42.1ºC) as well as low (11ºC) temperature besides being resistant to yellow mosaic disease. Pollen viability studies indicate 72% and 76% viable pollen at both low (11ºC) and high (42.1ºC) temperature, respectively. To transfer the desirable genes, three interspecific crosses were made involving RBL 9 with three mungbean varieties (KM 2241, TM 96-2, K851). Inter-specific cross K 851 x RBL 9 exhibiting maximum pollen fertility of 56.6%, with limited pod setting and resistance to MYMV disease might be useful in developing the high yielding mungbean genotypes.