Biological and Serological Identification of Barley Yellow Dwarf Virus (BYDV) and Its Distribution in Iraq

Abstract

Barley yellow dwarf virus (BYDV) was identified by means of symptoms on indicator plants, transmission by aphids, and serological characteristics. Symptoms of yellowing and stunting were appeared on leaf tips of Hordium vulgare, Triticum aestivum, and Avena fatua accompanied by stem stunting. Four species of aphids, Rhopalosiphum maidis, R. padi, Macrosiphum avenae, and Schizaphis graminum were found vectoring the virus. Extracts from wheat and barley plants showing yellowing and stunting were reacted positively with polyclonal anti-BYDV antiserum in DAS-ELISA. Most of samples that gave positive reactions by ELISA gave positive reactions with tissue blot immunoassay (TBIA). Higher incidence of BYDV was found in the northern parts of Iraq. Several economical and weed plants, collected from wheat and barley fields and vicinity sites have been found to harbor the virus. These hosts may acts as virus reservoir transmitting to wheat and barley plants by aphids.