Strains of YDV in autumn sown wheat grown in Canterbury

Abstract

The prevalence of the YDV strains PAV MAV and RPV in autumnsown wheat grown in Canterbury was determined for plants exhibiting symptoms (red or yellow leaves) and neighbouring plants with green leaves from up to 17 wheat fields in Canterbury New Zealand A leaf from up to nine plants was tested individually using ELISA Plants with red leaves and yellow leaves were predominantly infected with PAV The prevalence of PAV in plants with green leaves was less marked In red and yellow plants MAV and RPV were equally prevalent but markedly less common than PAV This is in contrast to barley and oat plants tested in 198586 where the predominant strains were RPV and MAV Barley plants tested from a single location in 1996 were predominantly infected with the MAV strain In the present study there was high variability between wheat fields