Identification of ‘ Ca . Phytoplasma asteris’, banana bunchy top virus and banana streak MY virus associated with Champa and Sabri banana cultivars in Tripura, a North Eastern state of India

Symptoms of bunchy top, little leaf, leaf chlorosis with chlorotic streaks, leaf necrosis and stunted growth were noticed in two banana cultivars, Champa and Sabri, in five districts of Tripura during 2019–2020. Symptomatic banana leaf samples was processed for association and identification of phytoplasma and viruses. Aster yellows phytoplasma (16SrI-D subgroup) were detected in both the cultivars at seven locations (Lembucherra, Boromura, Mohanpur, Cesrimile, Tuichindra, Udaipur and Kailasahar) in five districts of Tripura on the basis of 16S rRNA/ secA gene sequence comparison and virtual RFLP analysis of 16S rRNA gene sequences. Banana bunchy top virus (BBTV) and banana streak MY virus (BSMYV) were also detected and characterized in the symptomatic banana samples of both the cultivars from Tulacona, Champamura, Lembucherra, Morcherra, Longpong, Subalsingh, Hawaibari locations of the three districts. Phylogenetic analysis of BSMYV isolates, based on the RT/RNase H gene revealed two major cluster I and II, where all the BSMYV isolates identified in the present study were positioned under subcluster Ia, Ib and Ic. The BBTV phylogeny based on Rep gene classified all the seven BBTV isolates (IN1-IN7) in the south pacific group (II) but in a distinct subcluster II. Mixed infection of ‘ Ca . P asteris’, BBTV and BSMYV was also detected in the Sabri cultivar at Lembucherra in the West Tripura district. Our results suggest that aster yellows phytoplasma and two viruses (BBTV, BSMYV) are the major biotic stress responsible for banana stunting, bunchy top and little leaf with chlorosis symptoms in two popular banana cultivars in Tripura, India.