DAC-ELSSA AND INFECTIVITY ASSAY BASED IDENTIFICATION OF PEANUT BUD NECROSIS VIRUS (PBNV) AS INCITANT OF MUNG AND URDBEAN LEAF CURL DISEASES IN ALLAHABAD

摘要

Preliminary survey was conducted during kharif 2004 and 2005 to detect the natural infection of vira! diseases in standing crops of urd and mungbean in experimental trials at AAI-DU and farmer's fields in the vicinity of AAI-DU. Young tissue samples collected from suspected plants in crop wise were subjected to bioassay and DAC-ELISA. For bioassay, the samples were mechanically inoculated on to cowpea cv.152 (local lesion host) and to respective host plants under glass house conditions. Symptoms, physical properties of buffered sap like dilution end point (DEP), thermal inactivation point (TIP) and longevity in vitro (LIV) were studied separately for each crop isolate. Direct antigen linked immunosorbent assay (DAC-ELISA) was done by using PBNV antiserum diluted to 1:5000. All the mechanically inoculated cowpea leaves showed chlorotic spots from 6-8 days, which subsequently turned irregular chlorotic lesions from 11-12 days and finally the lesioned portions of leaves turned necrotic and dried within 16-17 days after inoculation. Glasshouse inoculated mung and urdbean from cowpea single lesion inoculations produced similar symptoms with negligible variations from natural infection, the DEP, TIP and LIV was found to be 10~(-2) (mung) 10~(-3) (urd),40-50°C (for both mung and urd) and 4 hrs (for both mung and urd). All the bioassayed samples were tested positive in ELISA. In the light of the present investigation involving serology, symptomatology and physical properties of buffered sap, the virusis confirmed as peanut bud necrosis virus (PBNV) inciting of leaf curl in mung and urdbean.