Vol. 10, Issue 12 (2021)

Author(s):
Salgar RD, Savant NV, Kumbhar CT, Vavre KB and Khadatare RM

Abstract:
Worldwide, french bean (Phaseolus vulgare Linn.) is one of the most important pulse crops, but having very low production due to biotic or abiotic stresses. Diseases are one of the most important causes for low production from biotic point of view. This crop is attacked by many viral diseases viz., Bean Common Mosaic Virus (BCMV), Bean Yellow Mosaic Virus (BYMV), Broad Bean Mosaic Virus, Bean Leaf Roll Virus (BLRV), Bean Distortion Dwarf Virus (BDDV), Mung Bean Mosaic Virus (MBMV), Bean Seed Borne Mosaic Virus, Dendrobium Mosaic Potyvirus (DeMV), Bean Southern Mosaic Virus (BSMV), Bean Pod Mottle Virus and Bean Mild Mosaic Virus (BMMV). Amongst all viral diseases, Bean Common Mosaic is an important disease. Hence, the present studies on Bean Common Mosaic Virus of french bean were proposed and carried out during the year 2018 to 2020. The experiments were carried out at the Department of Plant Pathology and Agricultural Microbiology, College of Agriculture, Pune (Maharashtra, India) and the screening of french bean germplasm against BCMV was carried out at Zonal Agricultural Research Station (Plain Zone), Regional Fruit Research Station, Ganeshkhind, Pune (Maharashtra, India). Results of the study clearly revealed that, the virus was mechanically/sap transmissible. It was also transmissible by insect and through seeds and pollens. The insect vectors, Myzus persicae, Aphis craccivora and Bemisia tabaci transmitted the virus in non-persistent manner. The host range study showed that, the BCMV virus was mainly confined to plants belonging to family Leguminosae, and symptoms observed on them included mosaic, mottling, blistering and puckering, necrosis, vein banding, reduction in pod size, overall stunting of plant, bending of leaf margins, downward curling of leaves as well as cupping of leaves. Physical properties viz., TIP, DEP and LIV of the virus under study were 60 ^oC, between 10^-3 to 10^-4 and 48 h (at room temperature), respectively. Based on these observations, virus infecting french bean (Phaseolus vulgare Linn.) was identified as Bean Common Mosaic Virus belonging to Potyvirus group (Family-Potyviridae). Appraisal of french bean germplasm under field conditions revealed that, out of 60 germplasm screened, none of the germplasm was found disease free. Eleven germplasm showed 1-10 % disease incidence, thirteen germplasm showed 11-40 % disease incidence, twenty-five germplasm showed 41-75 % disease incidence, eight germplasm showed 76-90 % disease incidence and three germplasm showed 91-100 % disease incidence.