为了明确S34‐1细菌对致病疫霉不同生育阶段的影响以及对晚疫病的控制效果，并初步探究拮抗物质的来源。本试验分别以对峙培养法、菌液与孢子囊悬液混合法测试细菌活体和菌液对致病疫霉菌丝生长以及菌体形态的影响，以块茎切片法评价菌液的防病效果，采用排除法探究拮抗物质来源。结果表明，S34‐1活体和菌液对致病疫霉菌丝生长有较强的抑制作用，抑菌率分别为89．32％和97．12％；菌液可使菌丝畸形、不规则膨大并释放内含物，明显抑制孢子囊释放游动孢子和游动孢子萌发；在马铃薯块茎切片上菌液对晚疫病有良好的预防效果，其抑菌物质是一种挥发性物质。试验表明利用S34‐1菌株防治马铃薯晚疫病有较大潜力。%The purpose of this experiment is to test the effect of bacteria S 34‐1 strain on differ‐ent development stages of Phytophthora infestans and control efficiency of potato late blight , and to analyze the anti‐oomycetes substances of this strain .The dual culture method was used for evaluating the inhibition effect of S 34‐1 strain living and bacterial fluid on mycelia grow th of P . infestans ,and sporangia suspension mixed with bacterial fluid method for assessing effect of the bacterial fluid on mycelia shape ,and potato tuber slices method for estimating the control efficience of late blight ,and exclusive method for analysis antimicrobial substances . The results showed that living and bacterial fluid of S 34‐1 strain strongly suppressed the my‐celial growth P .infestans ,the inhibition rates were 89 .32% and 97 .12% ,respectively .The bacterial fluid not only led in mycelia deformation with irregular enlargement and inclusion leak ,but significantly depressed zoospores release from sporangia and germination of zoo‐spores .In addition ,the evident control efficiency of bacterial fluid for late blight was obtained on potato tuber slices .The antagonistic substance produced by S34‐1 might be volatile mat‐ter .It is suggested that S34‐1 strain has a great potential in restraining P .infestans and con‐trol late blight in future .
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