Antagonistic Effect Of Bacillus Subtilis GY1 Strain On Four Species Of Fusarium Oxysporum

Fusarium wilt is a soil-borne vascular bundle disease caused by Fuasurium oxysporum,which damages more than 100 kinds of plants,such as Gramineae,Cucurbitaceae,Solanaceae,Leguminosae.These diseases cause huge economic losses.With the rapidly development of facility agriculture in China,the reduction of vegetables and the quality decline caused by blight are becoming serious year by year,which restricts the sustainable development of China's vegetable industry.However,current chemical control and agricultural control measures can't achieve the desired field control effect.The Biological control of Fusarium wilt by Bacillus subtilis will provide a new way for the green prevention and control the disease-Upon the basis of previous research on the biocontrol bacteria of Banana Fusarium wilt,we used Bacillus subtilis GY1 to study two species of Melon Fusarium wilt fungi and two species of Solanaceous Fusarium wilt fungi.Through the determination of mycelial inhibition rate,cell inhibition rate and spore germination inhibition rate,the antagonistic effect of GY1 strain on these four species of Fusarium oxysporum f.was determined.The control effect of GY1 strain on these four Fusarium wilt diseases was determined by greenhouse control effect test.This study will provide a theoretical basis for the antagonistic molecular mechanism of GY1 strain against melon and solanaceous Fusarium Wilt and the development and utilization of control agents.The results of this study are as follows:(1)The inhibition rates of spore germination of GY1 strain on Fusarium oxysporum f.sp.Cucumerinum,Fusarium ox-ysporum f.sp.Momdicae,Fusarium oxysporium f,sp.Lycopersici,and Fusarium oxysporum f.sp.Melongenae were 96.04%,83.13%,91.27,78.80%.(2)The mycelial inhibition rates of Bacillus subtilis GY1 against Fusarium oxysporum f.sp.Cucumerinum,Fusarium oxysporum f.sp.Momdicae,Fusarium oxysporium f.sp.Lycopersici,and Fusarium oxysporum f.sp.Melongenaet were 59.01%,60.12%,54.57%,59.01%.It can also cause mycelial expansion and deformity of four Fusarium wilt fungi.(3)The inhibition rates of GY1 strain on Fusarium oxysporum f.sp.Cucumerinum,Fusarium oxysporum f.sp.Momdicae,Fusarium oxysporium f.sp.Lycopersici,and Fusarium oxysporum f.sp.Melongenae were 86.07%,76.91%.88.40%and 83.64%.(4)The therapeutic effects of strain GY1 on Fusarium oxysporum f.sp.Cucumerinum,Fusarium oxysporum f.sp.Momdicae,Fusarium oxysporium f.sp.Lycopersici,and Fusarium oxysporum f.sp.Melongenae were 60.80%,62.68%,55.92%,58.86%.The preventive effects of GY1 Fusarium oxysporum f.sp.Cucumerinum,Fusarium oxysporum f.sp.Momdicae,Fusarium oxysporium f.sp.Lycopersici,and Fusarium oxysporum f.sp.Melongenae were 49.49%.44.59%,41.93%and 46.59.The above results indicated that Bacillus subtilis GY1 has strong antagonistic action against four species of Fusarium oxysporum,which also has good greenhouse effect,especially protective effect was significantly higher than therapeutic effect.