Occurrence of virus diseases of Bhut jolokia (Capsicum chinense)

Field surveys were carried out in three Bhut Jolokia growing districts viz., Sivasagar, Jorhat, Golaghat of Upper Assam to assess the incidence of viral diseases during 2009–11. The incidence of virus diseases varied in farmer's field with an average ranged from 8–72%. Four different viruses were identified based on symptomatology, transmission, host range and serological assays. The mosaic disease was detected to be cucumovirus, potyvirus leaf and stem necrosis disease to be caused by tospovirus and leaf curl disease caused by begomovirus. Cucumovirus, Potyvirus and Tospovirus were easily transmitted by grafting and sap inoculation to Bhut Jolokia and other hosts tested. However, begomovirus was found to be graft transmissible whereas sap inoculation failed to produce any symptom on host plants. Mixed infection of Cucumovirus and Potyvirus was separated by sap inoculation on Datura stramonium. Cucumovirus produced local lesion while Potyvirus produced chlorotic lesion on D. stramonium. DAS-ELISA revealed highest incidence of Potyvirus (87.50%) followed by Cucumovirus (75.00%) and Tospovirus (62.50%) in Golaghat while lowest incidence (31.25–33.33%) of virus diseases was recorded in Sivasagar for all the four viruses. However, overall incidence of Begomovirus was low in all the surveyed fields.