Occurrence of Groundnut bud necrosis virus on potato in North Western hills of India

摘要

Groundnut bud necrosis virus (GBNV) is a serious problem in many crops including potato where it causes potato stem necrosis disease. During a field visit in Shimla, potato plants showing clear symptoms of concentric necrotic rings along with necrosison the stem were observed. The virus was sap inoculated onto cowpea followed by back inoculation on potato plants in insect-proof cages under glasshouse conditions. Characteristic chlorotic spots which later turned into necrotic local lesions were recorded on cowpea and necrotic spots on potato leaves. Samples were processed for RT-PCR based detection, wherein an amplicon of expected size i.e., 560 bp was visible indicating the presence of suspected GBNV in the field collected potato leaf samples and also in sap inoculated cowpea and back inoculated potato plants as well. Insect vector thrips were also examined by print capture RT-PCR based detection and found viruliferous i.e., carrying GBNV.The other host like tomato was also examined for the presence of GBNV and the RT-PCR assay revealed the presence of GBNV in tomato, serving as an important reservoir of inoculum in North western (NW) hills of India. It was also found that the virus under study was present in the majority of the potato growing areas. Hence, the above observations suggest that GBNV started appearing on potato, especially in the NW hills of India despite unfavourable conditions.