Field Screening of Mungbean × Mashbean Inter-Specific Recombinant Genotypes Against Yellow Mosaic Disease (YMD)

Abstract

M (Vigna radiata L. Wilczek) is an excellent source of protein and an important short duration grain legume crop in humid and sub-humid climate of the world (Akhtar et al., 2011). Different metabolic processes occurring in a plant culminate in the final product, i.e., yield. Any disruption/disturbance in one or more of such processes caused due to biotic and abiotic stresses faced by the plant may reduce the actual yield, and due to these stresses, the average yield of mungbean is low. Among these stresses, diseases are the major causes of low yield (Malik and Bashir, 1992). The severity of various stresses is largely due to varying weather conditions that prevail throughout the year and may extend to next coming years, thus, lowering yield of pulses at farmer’s field and keeping it below the potential yield/economic level. The low yielding cultivars and susceptibility to diseases particularly to YMD transmitted by whitefly (Bemisia tabaci Genn.) are the major constraints causing low seed yield. YMD, caused by mungbean yellow mosaic India virus (MYMIV) is very devastating in Pakistan especially in the summer season Abstract | Yellow mosaic disease (YMD) caused by mungbean yellow mosaic India virus (MYMIV) is an important constraint of mungbean during the summer season in Pakistan. The use of resistant varieties is the only way to reduce the losses caused by YMD. Resistant sources had already been reported in mungbean, but no such information seems to be available for mung × mash interspecific recombinants. In this study, 72 mung × mash interspecific recombinant genotypes and a susceptible mungbean variety Mung Kabuli were screened against Yellow Mosaic Disease (YMD) using disease severity ratings by visual scoring of symptoms to calculate percent disease index (PDI). Tested recombinants responded differently to the disease. None of the tested genotypes was found to be disease free (field immune). However, combined data showed that 43 genotypes were highly resistant with 1.18 to 10 PDI while 29 were resistant with 10.24 to 24.85 PDI. Mung Kabuli (positive control) showed susceptible response with PDI value of 60 %. Thus 43 highly resistant genotypes proved to be a good source of resistance to YMD despite high disease pressure and can, therefore, be used directly as varieties to manage the disease after evaluation for acceptable agronomic characteristics, adaptation, and stability in various regions or can be used as a resistant source in further breeding programs. Ghulam Abbas1, Khalid Pervez Akhtar1, Muhammad Ahsan2, Muhammad Jawad Asghar1, Fiaz Ahmad1 and Muhammad Rizwan3*