Etiology of Phialophora new pathogenic species from wheat roots in Northwestern China Development of new materials resistant to clubroot by crossing Brassica oleracea with Brassica campestris via embryo rescue STUDY ON THE TECHNIQUES OF CHEMICAL CONTROL ON WHEAT ROOT DISEASE Marker-assisted Selection of Near Isogenic Lines for Clubroot Resistant Gene in Chinese Cabbage Marker-assisted Selection of Near Isogenic Lines for Clubroot Resistant Gene in Chinese Cabbage Effects of Clubroot Disease on Growth,Physiochemical Substance and Reactive Oxygen Metabolism in Pak-choi Effects of Inoculating Root Rot Fusarium on Alfalfa Seedlings STUDIES ON PATHOGENIC SPECIES OF PYTHIUM FROM SPRING CROPPING MAIZE SEEDLINGS IN ZHEJIANG PROVINCE