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期 刊 ：植物保护学报 2011年

关键词：稗草；新月弯孢菌；致病力；化学除草剂；混用效果；

Keywords:Echinochloa crus-galli, Culvularia lunata, pathogenticity, herbicide, synergism,

摘 要 ：为了确定生防菌新月弯孢菌Culvularia lunata菌株J15(2)的安全性及防除稗草的潜力,研究了该菌株的寄主范围,接种孢子时稗草叶龄、接种后保湿时间、接种浓度对该菌株致病力的影响,土壤带菌对稗草出苗的影响,以及与化学除草剂的相互作用。结果显示,菌株J15(2)只能在稗草上侵染并扩展;接种孢子后保湿24 h,对2叶期稗草抑制率可达55.6%,对1.5叶期稗草抑制率可达100%;保湿48 h,对2叶期稗草防效提高至91.6%;接种孢子量需达10¹² 孢子/hm²才能较好地抑制稗草生长;土壤带菌亦可抑制稗草生长。该菌与化学除草剂精噁唑禾草灵或二氯喹啉酸混用能显著提高除稗效果,菌株J15(2) 3.3×10¹² 孢子/hm²分别与精噁唑禾草灵有效剂量3.83 g/ hm²、二氯喹啉酸有效剂量250.00 g/hm²混用,对稗草防效分别为99.5%和88.6%,远高于这两个除草剂单用时的药效。该试验结果表明,菌株J15(2)具有作为微生物除草剂的开发潜力。

Abstract:The pathogen Culvularia lunata isolated from Echinochloa crus-galli is a potential mycoherbicide against this weed. The objectives of this study were: 1) to evaluate the safety of the pathogen as a mycoherbicide; 2) to determine the effects of E.crus-galli leaf stage, dew period, inoculation concentration, soil inoculation on the pathogenticity of the pathogen and the interaction between the pathogen and chemical herbicides. The result of host range test with 36 plant species showed that C.lunata severely infected only E.crus-galli and safe on tested crops. Under 24-h dew period, the inhibition rates of E.crus-galli were 100% and 55.6%, respectively, when the pathogen was inoculated at the 1.5-leaf stage and at the 2-leaf stage. Under 48-h dew period, the inhibition rate was up to 91.6% at the 2-leaf stage of this weed. Good E.crus-galli control was achieved when inoculated conidial amount was 10¹² spore /hm² or higher. The growth of this weed could be inhibited when the pathogen was inoculated into soil. Greenhouse experiments showed obvious synergistic effects between C.lunata and herbicide fenoxaprop-o-ethyl or quinclorac on the weed.

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