Identification and Characterization of Viruses causing Mosaic of Bottle gourd in Jammu sub tropics

Abstract

newline Bottle gourd (Lagenariasiceraria) holds an important place in the Cucurbitaceae family and is cultivated in all tropical and sub- tropical areas of world. This multipurpose crop faces many stresses (biotic and abiotic) wherein, viruses are a major group of pathogens causing mosaic disease. Bottle gourd mosaic disease is not only responsible for yield losses but also for inciting epidemics. Extensive survey of Jammu division to assess the status of bottle gourd mosaic disease was conducted during 2020 and 2021 and it was found that the average maximum disease incidence (53.33 %) was recorded from Salaher (R.S. Pura) while the lowest incidence (7.00 %) was recorded from Ratwal (Bishnah) of Jammu district. However, Jammu district recorded higher incidence of mosaic than other districts (Kathua, Samba and Udhampur). About 274 samples were collected from different locations and 55 symptomatic isolates were detectedfor causal virus/ viruses. Molecular identification of the causal viruses through RT-PCR revealed the presence of Cucumber green mottle mosaic virus (CGMMV)and Papaya ringspot virus (PRSV-W) by using coat protein specific primers. CGMMV CP primers amplified a 604 bp product while PRSV-W CP primer produced 398 bp amplicon which was further custom sequenced. CGMMV isolate shared maximum sequence identity (99.80 %) at nucleotide level with CGMMV isolate CG003 (MH271409)reported from USA while, PRSV-W isolate shared the highest per cent identity newline(96.23 %) with PRSV isolate SHK- PM1 from India(KY448325). The host range of the virus was restricted to Cucurbitaceae and Chenopodiaceae families only. During transmission assays, CGMMV isolate was not transmitted by insect-vector while, PRSV-W was transferred successfully by aphids (Aphis gossypii and A. craccivora) from infected to healthy plants.However,A. gossypii was found an efficient vector for the transmission of the virus. Seventy eight different germplasm were screened against bottle gourd mosaic disease under both field and controlled condition