First report of Groundnut bud necrosis virus infecting pea ( Pisum sativum ) in India

Abstract

During the winter season of 2008 and 2009 in Uttar Pradesh, India, symptoms of browning of veins, leaves and stem, mostly in growing tips, were observed in pea plants at the research farm of the Indian Institute of Pulses Research, Kanpur, and at the farm of G. B. Pant University of Agriculture and Technology, Pantnagar. Pods showed brown circular spots and later became completely brown. Affected plants finally dried up. The incidence of the disease was within the range of 1-10% in different fields. Failure to isolate a fungal or bacterial pathogen from leaves and pods showing symptoms, and symptoms resembling those associated with tospoviruses suggested tentatively that a tospovirus was the cause of the disease in pea. Sap inoculation in cowpea cv. Pusa Komal, from leaves and pods showing symptoms, resulted in the development of characteristic necrotic local lesions on the inoculated primary leaves, and subsequent systemic infection developed on newer leaves; these indicated a tospovirus disease aetiology. Tospovirus was confirmed by reverse transcription-polymerase chain reaction and direct sequencing using a specific primer pair for the amplification of the non-structural movement protein (NSm) gene of Groundnut bud necrosis virus (GBNV). GBNV has been reported to be associated with a necrotic disease of mung bean, potato, tomato and cowpea in India. This is thought to be the first report of GBNV affecting pea in India.