Identification of Wheat-Thinopyrum intermedium Telosomic Lines Resistant to Barley Yellow Dwarf Virus by GISH and STS Markers Converted from RFLP Cloning of cDNA Fragments Related to the Resistant Genes of Wheat Yellow Dwarf Virus Control effects of Trametes versicolor dextran on wheat yellow dwarf Evaluation of the resistance of wheat varieties and germplasm resources to BYDV-GAV Analysis of the wheat yellow dwarf epidemic and its predicting model of BP neural network in northwestern China FORECAST OF WHEAT YELLOW DWARF DISEASE