Tolerance to barley yellow dwarf viruses in two pairs of sister oat lines

Abstract

The titers of barley yellow dwarf viruses (BYDV-PAV-IL and BYDV-RPV-IL) in two pairs of sister oat lines tolerant and susceptible to BYDV-PAV were measured by double antibody sandwish enzyme-linked immunosorbent assay (DAS-ELISA) and by purification. There were consistent relationships between expression of symptoms and virus titers in tolerant and susceptible pairs of oat lines when inoculated in the greenhouse with PAV-IL or RPV-IL. In case of PAV-IL, the virus infects and accumulates to similar levels in shoot and root tissues of these lines. RPV-IL titers were higher in the susceptible line than in tolerant lines.

Translocation of barley yellow dwarf viruses (BYDV-PAV-IL and BYDV-RPV-NY) in those two pairs of sister oat lines was measured by trible antibody sandwish enzyme-linked immunosorbent assay (TAS-ELISA) and by dot blot hybridization. PAV-IL virus and PAV-IL-RNA titers in shoots and roots of tolerant lines were equivalent to or higher than the titers in susceptible oat lines. Thus, there was no inhibition of PAV-IL replication or movement in tolerant lines. Titers of RPV-NY virus and RNA in shoots of tolerant lines also were equivalent to or higher than the titers in shoots of susceptible oat lines. However, titers of RPV-NY virus and RNA in roots of susceptible oat lines were higher than the titer in tolerant oat lines on middle and late sampling dates. There apparently is some restriction on RPV-NY movement to and/or replication within the roots of these tolerant lines.