Reaction of certain wheat cultivars in different soil textures to root rots disease caused by Fusarium moniliforme, F. graminearum and / or drechslera sorokiniana

摘要

Five wheat cultivars (Giza 162, Giza 163, Giza 164, Sakha 8 and Sakha 69) cultivated in different soil textures (sandy, loamy and clay soil) varied in their susceptibility to root rots disease caused by F. moniliforme, F. graminearum and / or D. sorokiniana. None of the tested cultivars exhibited complete resistant to the disease in all tested soil textures. Susceptibility of tested cultivars varied according to soil textures. In general, Sakha 8 was the highest susceptible cultivar to all tested fungi in all tested soil textures, whereas Giza 162 was the least susceptible one. Spore germination and mycelial growth of all tested fungi were increased by root exudates of the tested wheat cultivars exuded in different soil extracts compared with rootexudates of the tested wheat cultivars exuded in water only. The stimulation of spore germination and mycelial growth effect varied according to cultivars exudates and the extracts of the tested soil textures. The most stimulation effect for mycelial growth and spore germination of the tested fungi was obtained by root exudates of the highly susceptible cultivars Sakha 8 compared with the least susceptible ones Giza 162 and Sakha 69. It also varied according to soil texture extracts. Root, exudates ofthe tested cultivars exuded in sandy soil extracts gave the highest stimulation effect of spore germination and mycilial growth of F. moniliforme and F. graminearum while their exuded in loamy soil extracts gave the highest growth of D. sorokiniana.