Survey, host range and characterization of begomovirus infecting bitter gourd and its vector whitefly cryptic species

Bitter gourd plants exhibiting various kinds of symptoms were collected in famer’s fields in Karnataka and Uttar Pradesh states of India. The casual agent associated with symptomatic bitter gourd plants (One sample) was artificially inoculated through whiteflies (Bemisia tabaci) to the healthy bitter gourd plants. Further host range studies indicate that it will infects few plant species in the Cucurbitaceae family.The status of the virus associated with bitter gourd plants was assesses by subjecting the total DNA of 80 symptomatic samples to PCR using begomovirus specific primers. The resulted PCR amplicon of 1.2 kb partial viral genome sequencing and analysis indicates that 80 symptomatic bitter gourd samples are infected by begomovirus, which is closely related to tomato leaf curl New Delhi virus (ToLCNDV). The representative bitter gourd samples were selected to amplify the complete viral genome of eight isolates using RCA method. The pair wise nucleotide sequence analysis of DNA-A (nucleotide identity of 92.8–97.6%) and DNA-B (nucleotide identity of 82.9–95.1%) of eight bitter gourd isolates showed more homology with ToLCNDV affecting cucurbits, lentil, chilli, tomato, bitter gourd and pumpkin. The recombination break point analysis of the complete genome of eight bitter gourd isolates indicates these isolates are exchange the DNA fragments in both the components with already prevailing begomoviruses. The cryptic species of the whiteflies identified as Asia-I and Asia-II-5 group, which were collected from infected bitter gourd fields. The significance of these research findings is discussed.