BARLEY YELLOW DWARF VIRUS SYNTHESIS IN CEREALS IN RELATION TO RESISTANCE AND SUSCEPTIBILITY

MANI SKARIA, Purdue University

Abstract

Barley yellow dwarf virus (BYDV) contents in extracts from cereals inoculated and grown in greenhouse, growth chambers, or field were compared by enzyme linked immunosorbent assay (ELISA). In experiments with cultivars of wheat, oats, and barley inoculated with isolates of BYDV, non-specifically transmitted by Rhopalosiphum padi L. and Sitobium avenae Fabr., the number of aphids used for inoculations had no effects on symptoms, or on virus content as assessed by ELISA. Virus contents were similar at each sampling dates during one month after inoculation whether the plants had been infested with 2 or 10 aphids. For some virus-host combinations symptomatic 'resistance' to BYDV, as previously determined by plant breeders, was associated with reduced virus synthesis in infected plants. Though this effect is cultivar and virus isolate specific, it could be a valuable adjunct in breeding cereal lines for BYDV resistance and management. In breeding for BYDV resistance, the behavior of cereals in the field exposed to BYDV could reasonably be predicted by short term experiments done under controlled conditions in a growth chamber. The BYDV content in cereals simultaneously or sequentially inoculated with PAV or RPV was compared with that of plants singly inoculated with the respective isolates. When simultaneously inoculated, both PAV and RPV types multiplied equally well; when inoculated sequentially, PAV multiplied well in plants which were first inoculated with RPV and vice versa.

Degree

Ph.D.

Subject Area

Plant pathology

COinS