【摘要】 用针在棉花叶片表面0.5 cm2的面积上刺15~20个小点,然后将黄萎菌毒素溶液涂抹于针刺部位,观察记载处理部位的萎蔫程度,由此检测黄萎菌毒素对棉花致萎性的强弱。利用层析纯化的黄萎菌V991毒素对棉花的致萎性试验表明:棉苗的子叶为最佳接种部位,毒素对陆地棉感病品种鄂荆3号的致萎下限为7.3μg,接种24 h即可表现萎蔫症状。用8个不同致病力黄萎菌系的培养滤液(简称滤液)针刺涂抹3个不同抗病性陆地棉品种,同时设置相应毒素浸泡参比试验。结果表明,利用培养滤液,即可以快速、准确地检测滤液的致萎力强弱,该方法既可用于棉花品种资源对黄萎病的抗性鉴定,又可用于比较黄萎病菌的不同生理型。更多还原

【Abstract】 A new method,measuring the extent of wilting by pricking on leaf surface and spreading on cotton,has been developed.First,V.d.-toxin（phytotoxin of Verticillium dahliae） of V₉₉₁ which is a severe defoliating virulence strain of Verticillium dahliae on cotton was purified partially with Sephacryl S-200 HR;next,cotyledon or euphyla of seedling of cotton was pricked 15²0 pinhole in 0.5 cm² area on the surface with small needle;then,V.d.-toxin was spreaded on it;and wilting symptom was recorded after 24 h,taking water and BSA as the control.The extent of wilting could be divided into 5 classes from 0 to Ⅳafter 24 h.Apart from the purified V.d.-toxin,the filtrate（liquid culture medium filtered after culturing V.d.over 7 days） can be taken as this method yet.To validate the method above further,8 strains of V.d have been selected to do the repeat tests,which belong to severe wilting strains(V₉₉₁,T₉,V₅₆ and V₁₄₆),weakness wilting,strains(V₁₁₀,V₂₄₆,V₂₅₀) and medium wilting strain of V_3-10-1.By pricking on leaf surface and spreading V.d.-toxin on cotton individually,the answers appears that their potential power of wilting can be easily measured and divided into corresponded groups,such as V₁₂₀,V₉₉₁ and T₉ belong to the severely type after testing.This dividing way is as same as the ever measurement with traditional ways（such as soaking seedling method）.To identify the most suitable stage and part of the leaf to treat on cotton plant,we have tested to treat them both cotyledon and euphyla in seedling and euphyla in adult plant.As the result,this method can be utilized as early as in seedling stage,and cotyledon is better than euphyla since it is easy to prick but not to pore through.However,the extent of wilt has been appeared varying usually according to the temperature in environment,cotyledon or euphyla of seedling,and the concentration of V.d.-toxin.To identify the differential reaction of cultivars on cotton to V.d.-toxin with this method,we have chosen 4 cultivars of upland cotton which are Ejing-3,B99261,CCRI 12,Xingluzao-7. We have conducted different cultivar treatments with the same V.d.-toxin,and compared the coherence between V.d.-toxin soaking way to the way of pricking on leaf surface and spreading V.d.-toxin.The result indicated that both methods can get very similar results after repeating tests.更多还原