Wheat yellow mosaic virus widely occurring in wheat (Triticum aestivum) in China

Wheat yellow mosaic virus (WYMV) was identified in 25 of 27 wheat (Triticum aestivum) samples from six provinces in China using reverse-transcription polymerase chain reaction. Wheat spindle streak mosaic virus was not detected. Thus, contrary to previous reports, WYMV was the only bymovirus detected in wheat in China. The cDNA fragments corresponding to coat protein coding regions of five WYMV isolates from China were cloned and sequenced. Deduced amino acid comparison of coat proteins among these five isolates, another Chinese WYMV isolate HC, and one isolate from Japan showed very high sequence conservation, particularly in both the N- and C- termini. However, a highly virulent isolate HC from Henan Province showed four amino acid substitutions in highly conserved amino acid positions which might play a role in its pathogenic variation.