SEASONAL OCCURRENCE OF BARLEY YELLOW DWARF VIRUS SEROTYPES IN SMALL-GRAIN CEREALS IN THE VALLEY OF MEXICO

We assessed the occurrence of serotypes of barley yellow dwarf virus (BYDV) in an area at the International Maize and Wheat Improvement Center (CIMMYT) used to screen germ plasm for field resistance to BYDV. Wheat and barley plants were labeled in the field, and leaves were sampled several times during plant development to monitor BYDV incidence. Samples were tested by enzyme-linked immunosorbent assay with a panel of monoclonal and polyclonal antibodies. Samples from plantings sowed on different dates were tested to investigate seasonal influences on BYDV occurrence. Up to 88% of the plants sowed in winter (November and January) became infected. Fewer infections were detected in summer sowings (May). MAV serotypes predominated in both winter and summer sowings.