Seed Transmission Behaviour of Bean Common Mosaic Virus in Green Gram

Abstract

Background: The virus-distribution and bimodal seed transmission of BCMV in green gram was studied. The Bean common mosaic virus (BCMV) infecting leguminous crops have been found to be the most devastating Potyvirus as they cause considerable yield loss. Emergence of symptom in the first trifoliate leaf stage of the plants under the natural condition confirms that the virus may be seed borne, which has been investigated in the present study. Methods: The distribution of the virus in various parts of the seeds of mung bean (Vigna radiata) plants naturally infected in the field was determined by ELISA, polymerase chain reaction (PCR) and sequencing. Result: Nucleotide sequencing of the PCR amplicons from the seed parts from groups of ten seeds revealed the presence of Bean common mosaic virus (BCMV) in the seed coat, cotyledon and embryonic axes. The grow out test performed with the same batch of seeds, there was symptom development after 3 weeks of sowing and the presence of virus was detected in all the seedlings through ELISA test. RT-PCR amplification of viral cDNA from whole seed, seed coat, cotyledons and embryo generated an amplicon of ~1300 with BCMV coat protein gene specific primer. The genomic sequence (GenBank accession No. ON944468) showed highest nucleotide identity of 90-91% sequence similarities with NL-1 strain (KF114860.1) and 94% sequence similarities with MY15-014 strain (MW079241.1) of previously available BCMV- CP virus gene sequence.