Survey for viruses in lentil and chickpea crops in Pakistan

In an intensive sun,ey of lentil and chickpea fields and research stations plots carried out in the Punjab province of Pakistan in 1997, more than 650 5 plant samples were collected and tested by tissue-blot immunoassay (TBIA) for the presence of 14 different viruses. Overall, about one in five plant s of lentil was virus infected, 15 % of fields having incidences higher tha n 50 %. In contrast. incidences of infection were mostly low in chickpea. P ea seed-borne mosaic virus (PSbMV, genus Potyvirus, family Potyviridae) fol lowed by Cucumber mosaic virus (CMV, genus Cucumovirus, family Bromoviridae ), both of which are aphid-transmitted and seed-borne in chickpea and lenti l, were the most abundant viruses in lentils, and also occurred in chickpea . Chickpea chlorotic dwarf virus (CCDV, genus Mastrevirus, family Geminivir idae), Beer western Yellows virus (BWYV, genus Polerovirus, family Luteovir idae) and 'chickpea luteovirus' (family Luteoviridae) were common in chickp ea fields and were present in lentil. Faba bean necrotic yellows virus (FBN YV, genus Nanovirus) was occasionally found in lentil and chickpea fields, and Alfalfa mosaic virus (AMV, genus Alfamovirus, family Bromoviridae) in c hickpea fields. Counting plants with virus symptoms greatly underestimated virus incidence in lentil crops but was a better guide to virus occurrence in chickpea. Because of associated yield losses, the high incidences of inf ection in lentils are cause for concern for lentil production. Virus incide nce was sometimes sufficient within individual chickpea fields to be of con cern.