COMPARISON AND DIFFERENTIATION OF WHEAT YELLOW MOSAIC-VIRUS (WYMV), WHEAT SPINDLE STREAK MOSAIC-VIRUS (WSSMV) AND BARLEY YELLOW MOSAIC-VIRUS (BAYMV) ISOLATES USING WYMV MONOCLONAL-ANTIBODIES

Twelve monoclonal antibodies (MAbs) were obtained by immunizing mice w ith a French isolate (F1) of wheat yellow mosaic virus (WYMV). Three o f these (3D12, 2C1, 6C3) belong to the IgM class and the nine others t o the IgG class (3D8, 3H1, 2B8, 1F2, 3C10, 4F12, 3H9, 1G5, 54). In ant igen-coated plate (ACP) ELISA and indirect double antibody sandwich (I DAS) ELISA, all MAbs recognize the WYMV (F1) both in the form of purif ied particles and in wheat leaf extract. The analysis of numerous Fren ch isolates of WYMV shows a variable reactivity with MAbs 3D8, 3H1,2B8 , 3C10, 3H9 and 1G5 in IDAS - and ACP-ELISA. The Japanese isolate of W YMV and United States isolates of wheat spindle streak mosaic virus (W SSMV) were detected in IDAS- and ACP-ELISA by ten of the MAbs tested s howing that the wheat bymoviruses originating from the three locations share a high epitopic homology. French isolates of barley yellow mosa ic virus (BaYMV; pathotypes 1 and 2) were only detected in ACP-ELISA w ith MAbs 6C3, 3D8, 3H1 and 2B8 whereas the two Japanese strains (I-1, II-1) of MaYMV were recognized with these and also with that of 3C10. In IDAS-ELISA, the two Japanese strains were clearly detected by MAbs, 6C3, 3D8, 3H1, 1F2, 3C10 and 1G5 and the British and Belgian (pathoty pe 2) isolates only by that of 6C3. Only the Japanese strain of BaYMV, 1-1 could be detected with MAb 3H9 in this ELISA system.