【作者】 龙建友；

【导师】 吴文君；

【作者基本信息】 西北农林科技大学 ， 农药学， 2003， 硕士

【摘要】 作者于2001年5月至2003年5月对土壤中放线菌的杀虫、杀菌和除草活性物质进行了初步筛选研究，主要取得了以下结果： 采用常规的放线菌分离方法，以高氏一号培养基、精氨酸-甘油琼脂培养基、葡萄糖-天门冬素琼脂培养基、蔗糖察氏琼脂培养基和牛肉膏蛋白胨培养基为分离用培养基，从12个省份采集的土壤中分离得到了104株放线菌。 以粘虫为试虫，测定了104株放线菌发酵液的胃毒和触杀活性。结果表明，这104株放线菌的发酵液对3龄粘虫均无活性。 以反枝苋为供试杂草，测定了104株放线菌发酵液的除草活性。结果表明，仅No.24菌株的发酵液对反枝苋有强烈的抑制生长作用，其对主根生长抑制率为80.6％，对主茎生长抑制率为66.5％。 以番茄灰霉病菌(Botrytis cintrea)、小麦赤霉病菌(Fusarium graminearum)、烟草赤星病菌(Alternaria longipes)、马铃薯干腐病菌(Fusarium oxysporium)、玉米大斑病菌(Exserohilum turcicum)、南瓜枯萎病菌(F. oxysporium f. sp pumpkin)、苹果炭疽病菌(Glomerella cingulata Schr. et. Spauld)、苹果轮纹病菌(Macrophoma kuwatsukai)、番茄早疫病菌(Alternaria solani)为供试菌，采用抑制菌丝生长速率法对104株放线菌发酵液进行了杀菌活性筛选，结果发现No.24，No.65、No.68和No.102菌株的发酵液对供试病原菌有不同程度的杀菌活性。盆栽试验结果表明，这4个菌株的发酵液对小麦白粉病的保护作用在78.9％～84.3％之间，对小麦白粉病的治疗作用在43.7％～76.1％之间。 采用活性追踪法、HPLC制备技术，从No.24菌株发酵液中分离得到8个馏分，其中馏分4的除草活性最强，对反枝苋的主根生长抑制率为95.84％，主茎生长抑制率为93.76％，对反枝苋的种子萌发抑制率为86.36％。馏分7的杀菌活性最强，对酵母菌的抑菌圈直径为2.4cm。 采用基质菌丝、气生菌丝、孢子和孢子丝相结合的分类方法，对No.24放线菌菌株进行了鉴定，初步判断No.24为链霉菌属(Streptomyces)。更多还原

【Abstract】 The primary studies on screening of actinomycetes which metabolize the insecticidal, fungicidal and herbicidal components in soil have been carried out from May, 2001 to May, 2003. The main results are as follows:Taking Cause’s Synthetic medium, Glucose Aspargine Agar medium, Arginine Glyceral salt Agar medium, Czapek medium and Gorodkowa medium as separating culture medium, 104 strains of actinomycetes were separated from the soil collected in 12 provinces of China.The activities of stomach poison and contact poison of the fermentation products of 104 strains were tested against the 3th instar larvae of Mythimna separata. The results showed that the fermentation products of 104 strains exhibited no insecticidal activity against the tested larvae.The herbicidal activity of fermentation extracts of 104 strains were tested against the Amaranthus retroflexus L. The results showed that only the fermentation products of No.24 had an intensive herbicidal activity against Amaranthus retroflexus L, and had an inhibition of 80.6% to taproot, an inhibition of 66.5% to caulis.By means of mycelium growth rate ,the fermentation products of 104 strains were tested against Botrytis cintrea, Fusarium graminearum, Alternaria longipes, Fusarium oxysporium, Exserohilum turcicum, F.oxysporium f.sp pumpkin, Glomerella cingulata Schr.et.Spauld, Macrophoma kuwatsukai, Alternaria solani. The results showed that thefermentation products of No.24, No.65, No.68 and No.102 had a certain degree fungicidal activity. The results of pot test indicated that the fermentation products of No.24, No.65 and No.102 exhibited 78.9%--84.3% of protective efficacy ,43.7%~76.1% of therapeutic efficacy.Eight fractions were isolated from the fermentation products of No.24 strain by bioassay-guided and Pre-HPLC. The fraction No.4 had the most intensive herbicidal activity, the inhibiting rate of No.4 was 95.8% , 93.76% and 86.36% against the taproot ,caulis and the bourgeon of Amaranthus retroflexus L respectively. The fraction of No.7 had the most intensive fungicidal activity. The diameter of inhibition zone was 2.4 centimeter against microzyme.By means of observation OD substrate mycelium, aerial mycelium, spore and sporothrix, No.24 strain was primaryly identified asStreptomyces.更多还原