Status of Barley Yellow Dwarf and Cereal Yellow Dwarf Viruses Infecting Barley in Ethiopia

Abstract

A survey for Barley Yellow Dwarf Luteoviruses (BYDVs) and Cereal Yellow Dwarf Polerovirus (CYDV) was carried out from 1997/98 - 2000/2001 main and 2001 short rainy seasons in barley growing areas o f central, north, and west Ethiopia. Barley fields were inspected randomly at 5 km intervals and data related to altitude, growth stage, severity and incidence was recorded from each field. Tissue blot immunoassay was used to test samples against the BYDV and CYDV isolates. During the 1997/98 main rainy season, BYDVs and CYDV were prevalent and identified from 72% and 69% o f the fields studied in Arsi and west Shewa zones, respectively. All isolates, singly or in mixed infection, were detected, with BYDV-PAV being the most and CYDV-RPV the least distributed. Similarly, all BYDVs and CYDV in Amhara, and only BYDV-PAV in Tigray regional states were identified in north Ethiopia during the 1998/99 and 1999/2000 main rainy seasons. In the Oromiya regional state in west Ethiopia, BYDV-PAV was detected rarely during the main rainy season o f 2000. On the contrary, high BYDV-PAV prevalence and incidence was recorded in west Shewa zone, where it was detected in 93% o f the locations and 74% plants tested. Disease severity score o f 5 - 7 was recorded in 78% fields observed. BYDV-PAV was
detected at low level in areas surveyed during the short rainy season o f 2001.