棉籽带枯萎病菌检验方法的研究

棉籽带菌是远距离传病的主要途径。病棉株种子带菌率0.01—46.8%。带菌部位以种壳为主,但子叶、胚均带菌。棉籽上除带枯萎病菌外,还带有半棵、串珠、茄病、木贼等几种镰刀菌及其他杂菌,干扰检验。文中介绍一种选择性培养基,其成分为:甲基纤维素1克、KH_2PO_4克、蛋白胨5克、MgSO_4·7H_2O0.5克、K_2S_20.2克、KCl 0.6克,NH_4NO_30.3克、五氯硝基苯0.1克、蔗糖20克、链霉素0.1克、琼脂20克、蒸馏水1000毫升。应用其进行分离培养棉籽,可根据菌落形态特征及颜色反应,较容易地检验出棉花枯萎病菌。

STUDY OF METHOD FOR DETECTING COTTON SEED BORNE FUSARIUM WILT FUNGUS

Cotton seeds are agents for long distance dissemination of cotton wilt.Seed borne rate of the Fusarium wilt is about 0.01% to 46.8%. The pathogens attack the seed-coat,cotyledon and embryo.Among the seed-borne fungi,Fusarium semitectum B.& R.,F. equiseti(Carda)Sacc.,F. moniliforme Shel.,F.solani(mart.) Sacc. and others may be isolated.These isolates usually interfer the detection of F.oxysporum f.sp.A selective medium for examining the cotton seed was formulated.It is composed of lg methyl cellulose,lg KH₂PO₄,5g peptone,0.5g MgSO₄·7H₂O,0.2g K₂S₂O₅,0.6g KCl,0.3g NH₄NO₃,0.1g pentachloro-nitrobenzene,20g sucrose,0.1g streptomycin sulfate,20g agar,1,000 ml distiled water.This medium has successfully been used on detecting cotton wilt fungus according to the selective differential pigment and morphological characteristics of the colony of Fusarium oxysporum f.sp.vasinfectum.