棉秆生物炭对大丽轮枝菌生长及毒素作用的影响

摘要

The verticillium wilt of cotton is difficult to control because microsclerotia formed by Verticillium dahlia kleb .can resist the adverse environment and allow a long-term survival in the soil .The application of cotton biochar can overcome the disadvantages of straw returning and prevent the entrance of Verticillium dahlia kled .into the soil .The ob-jective of this study is to explore the influence mechanism of cotton biochar on Verticillium dahlia kleb .by examinig the effects of cotton biochar on the mycelial growth ,microsclerotium germination and toxin secretion of Verticillium dahlia kleb .Shake cultivation and plate culture were used to test the resulting influences of cotton biochar on the mycelial growth of V . dahlia and the germination of microsclerotium .The dish dipping method was used to observe the germina-tion of cotton seed and melon seed to investigate the effects of biochar on reducing toxicity of Verticillium dahlia .Results showed that cotton biochar had no significant effects on the mycelial growth of V . dahlia under liquid culturing condi-tion ,while it had promotional effects under solid culture condition .In addition ,cotton biochar inhibited the germination rate of the microsclerotium .As treatment time went on ,the inhibition effect became disappeared .Moreover ,the addition of cotton biochar seriously reduced the toxicity of V . dahlia under liquid culture conditions .At the mid-stage of liquid culturation ,cotton seed germination rates were 53 .3% and 33 .3% after 12 days in the treatments of 2 .0 g·L-1 biochar and CK ,respectively ( P<0 .05) .At the prophase ,middle and late stages ,the seedling length with the treatment of 0 .5 g·L-1 biochar were 3 .9 ,1 .1 and 2 .2 times more than that with the CK treatment ,respectively .Compared to CK , biochar enhanced the melon seed germination , radicle length , plumule length and seedling length . In conclusion , biochar could slightly inhibit the mycelial growth and microsclerotium germination of V . dahlia ,while it could signifi-cantly reduce the toxicity of V . dahlia .%棉花黄萎病难以防治的根源在于大丽轮枝菌 Verticillium dahliae Kleb在土壤中形成的微菌核能抵抗不良环境，并在土壤中长期存活，将棉秆加工成生物炭施入棉田，可克服棉秆直接还田的缺点，从源头上防止黄萎病菌进入土壤。为探索棉秆生物炭还田对棉花黄萎病原菌的影响机理，采用液态摇床培养及平皿固态培养法研究生物炭对大丽轮枝菌菌丝生长及微菌核萌发的影响；通过平皿内棉花和甜瓜种子发芽试验研究生物炭对大丽轮枝菌毒素的减毒作用。结果表明：液态培养条件下，棉秆生物炭对大丽轮枝菌菌丝生长抑制作用不明显，在固态培养下对菌丝体生长有一定促进作用；生物炭能减慢微菌核的萌发速率，但对最终萌发率无影响；液态培养中加入棉秆生物碳对大丽轮枝菌毒素有较强的减毒作用。在摇床培养中期，加入2．0 g·L－1生物炭处理与对照棉种在培养12天时的发芽率分别为53．3％与33．3％（ P＜0．05）；前期、中期及后期加入0．5 g·L－1生物炭处理的棉花幼苗总长度分别为对照的4．9、2．1倍及3．2倍；加入棉秆生物碳处理甜瓜种子发芽率、胚根长度、胚轴长度及总苗长较对照均有不同程度增加。表明棉杆生物炭对棉花黄萎病菌大丽轮枝菌菌丝生长、微菌核萌发的抑制作用较弱，对大丽轮枝菌毒素危害有较强的减毒作用。