NATURAL HOSTS AND EFFICIENCY OF LEAFHOPPER VECTOR IN TRANSMISSION OF WHEAT DWARF VIRUS

Abstract

Wheat dwarf virus (WDV) occurs in economic proportions in cereal crops in Iran. Conventionally, it has two strains each adapted to wheat (WDV-W) or barley (WDV-B). A number of gramineous weeds were collected from the main wheat and barley cultivations in Fars province, Iran, in October 2013 and May 2014 and tested for WDV infection by PCR. WDV-W was detected in Aegilops kotschyi, Avena fatua, Bromus commutaus, Hordeum murinium, Lolium persicum, Sorghum halepense and Cynodon dactylon. H. spontaneum was the only host infected by WDV-B. WDV infection was detected more frequently in fall than in spring. The leafhopper vector, Psammotettix alienus, transmitted WDV to wheat and barley seedlings more efficiently after 7-day acquisition than after 1-day acquisition access period. Furthermore, using a different number of leafhoppers per plant led to significantly different (P<0.01) infection rates by the two strains in barley and wheat plants. Comparison of WDV- W and WDV-B infection rates in the two hosts indicated that WDV-W was able to infect both hosts with higher level than WDV-B.