Differentiation of strains of bean common mosaic virus

Abstract

Pathogenicity and symptom expression of seventeen described isolates of bean common mosaic virus (BCMV) and five previously unreported isolates were compared on many bean cultivars (Phaseolus vulgaris L.). From these cultivars, a standard set of differentials were assigned to nine groups with different disease reactions. The twenty-two virus isolates comprised seven strain (pathotype) groups, three of which were divided into two subgroups each. To promote international standardization in BCMV research, recommendations are given for test conditions and procedures, criteria for strain differentiation, and maintenance of differential cultivars and virus strains. Introduction and literature review

Analysis of 3′-Terminal Region of Bean common mosaic virus Strains Infecting Common Bean in India

“…Virus and Strain Identity DAS-ELISA test using BCMV specific antiserum established the identity of the test isolates as BCMV and reaction pattern on CIAT bean differential set [6] confirmed the strain identity as NL-1, NL-1n, NL-7 and NL-7n (Table 1). Isolates of NL-1n and NL-7n strain caused local and veinal necrosis on cv.…”

“…Nine isolates of BCMV strains BCMV-57(NL-1), BCMV-65(NL-1), BCMV-58(NL-1n), BCMV-59(NL-1n), BCMV-60(NL-1n), BCMV-62(NL-7), BCMV-64(NL-7), BCMV-61(NL-7n) and BCMV-63(NL-1n) were used in this study and their identity as BCMV was established through Double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA) using polyclonal antiserum (Loewe Biochemica GmbH, Germany). A standard set of common bean differentials was used to confirm the identity of the virus strains [6]. Virus inoculum was prepared as per standard procedure [11] and five plants from each differential cultivar in host group I-V were inoculated with each isolate using leaf rub method and one un-inoculated plant was kept as control [6].…”

“…A standard set of common bean differentials was used to confirm the identity of the virus strains [6]. Virus inoculum was prepared as per standard procedure [11] and five plants from each differential cultivar in host group I-V were inoculated with each isolate using leaf rub method and one un-inoculated plant was kept as control [6]. To identify necrosis inducing isolates, three plants of host group VI to IX, were inoculated and maintained in growth chamber at [30°C with 14-16 h light (Saveer India Ltd).…”

“…To identify necrosis inducing isolates, three plants of host group VI to IX, were inoculated and maintained in growth chamber at [30°C with 14-16 h light (Saveer India Ltd). Test isolates were identified as strains and assigned a pathogroup based on their reaction on a particular host group as per the procedure of Drijfhout et al [6]. Symptomless expression in resistant plants was confirmed by DAS-ELISA and reverse transcription-polymerase chain reaction (RT-PCR) using BCMV specific primers.…”

“…The coding ORF is translated into one polyprotein of 340-370 Da which is processed into proteinase (Pro-1), helper component proteinase (HcPro), proteinase (Pro-3), a 6 kDa protein, cylindrical inclusion (CI), a second 6 kDa protein product, nuclear inclusion a (NIa), nuclear inclusion b (NIb) and CP [8]. BCMV is known to possess high pathogenic variability in Europe, USA and Africa, and virus strains have been identified on bean differentials [6,7,12,19,22,28]. There are reports of BCMV occurrence on common bean in India and BCMV recurs regularly in this region with an incidence ranging from 0.5 to 77.0 per cent causing economic losses [23].…”