Sequence variability and phylogenetic relationship of betasatellite isolates associated with yellow vein mosaic disease of mesta in India.

Six betasatellite isolates associated with the yellow vein mosaic disease in mesta crops grown under three different geographical locations of India have been characterized. These six isolates and the one previously reported from eastern India could be divided into two distinct Types. The first Type, consisted of four betasatellite isolates characterized from northern and southern regions of India, was observed to be the newer isolates of Ludwigia leaf distortion betasatellite. The second Type, comprised three betasatellite isolates obtained from the eastern part of India, showed highest sequence identity with Cotton leaf curl Multan betasatellite and appeared to be the newer isolates of it. These isolates present within each of these two betasatellite species showed limited variability with respect to their individual group. The results thus indicated the association of two different betasatellite species with yellow vein mosaic disease of mesta in India and highlighted the possible adaptation of mesta crops as a newer hosts by these two betasatellite species.