EFFECTS OF TEMPERATURE ON BYDV CONCENTRATION IN OAT PLANTS AND VIRUS PURIFICATION EFFICIENCY, AND DETECTION OF A PUTATIVE ASSOCIATED SATELLITE VIRUS

RPV and MAV-like serotypes of barley yellow dwarf virus (BYDV), design ated R-568 and F, were found during sucrose density gradient centrifug ation to suspend at 10-degrees-C and 4-degrees-C but to totally sedime nt at 15-degrees-C and 12-degrees-C, respectively. These properties we re used to purify these serotypes, and antisera were then prepared. Pa rtially purified IgG from antiserum was used in immunosorbent electron microscopy (ISEM) and in enzyme-labelled immunosorbent (ELISA) tests to detect BYDV RPV-like serotypes. Using anti-BYDV R-568 polyclonal an tiserum and the BYDV R-568 serotype in ISEM tests, isometric virus par ticles of two sizes were trapped: the 28 nm particles of BYDV R-568, a nd others 17 nm in diameter which may be those of a satellite virus. T he effects of temperatures on virus concentrations in oat plants infec ted with BYDV serotypes F and R-568 were investigated. BYDV F and R-56 8 concentrations in the roots and shoots were sensitive to changes in temperature between 10-degrees-C and 25-degrees-C. The concentrations of both viruses in the roots and shoots of infected plants could be ma nipulated by varying the temperature at which plants were grown. The E LISA absorbance values related to detection of F MAV-like serotypes we re higher in roots and shoots of oats grown at 10-degrees-C than for o ats grown at 25-degrees-C. Conversely, cool temperatures reduced the a bsorbance values for R-568 RPV-like serotype in the roots, but less si gnificantly in the shoots.