【作者】 罗晓华；

【导师】 文成敬；

【作者基本信息】 四川农业大学 ， 植物病理学， 2003， 硕士

【摘要】 对雅安辣椒生长期土壤中木霉的分离、鉴定及室内拮抗试验，筛选到大量的拮抗菌株。利用拮抗作用强的菌株开展了对辣椒疫霉病的生防和促生盆栽试验及木霉在辣椒植株根际定殖模式的研究，为辣椒疫霉病的生防提供理论依据与科学参考。 从雅安郊区辣椒生长期土壤中0-5cm、5-10cm两个深度分别五点取样，共得到木霉58个菌株8个种。它们分别是T.harzianum、T.pseudokoningii T.citrinoviride、T.atroviride、T.longibrachiatum、T.hamatum、T.konigii T.aureoviride。同时土壤5cm深处哈茨木霉、拟康木霉和康氏木霉含量较多，属优势种群，黄绿木霉、桔绿木霉和钩状木霉次之，长枝木霉和深绿木霉没有发现；而土壤10cm处拟康木霉、桔绿木霉和深绿木霉含量较多，属优势种群，康氏木霉、黄绿木霉和长枝木霉次之，钩状木霉和哈茨木霉没有发现。这表明钩状木霉和哈茨木霉习居于土壤表层，长枝木霉和深绿木霉习居于土壤深层，其它木霉种群居于土壤中深度选择性不强。随着辣椒土壤温度升高，土壤含水量的减少以及土壤深度的加深，木霉在辣椒土壤中的种群数量也逐渐减少。 从辣椒土壤分离得到的木霉产生的非挥发性代谢产物对辣椒疫霉病菌的抑制作用表明桔绿木霉、哈次木霉、拟康木霉和康氏木霉对辣椒疫霉菌菌丝有较强的抑制作用，其平均抑制百分率分别为56.4％、69.1％、67.2％、63.6％；而其它几种木霉的非挥发性代谢产物对辣椒疫霉病菌的抑制作用都小于15％，且没有显著性区别。对峙培养表明哈次木霉、拟康木霉和康氏木霉对辣椒疫霉病菌菌丝有溶解、断裂、扭曲、缠绕等作用，最终导致其崩解、死亡。木霉易非发性代产物对辣椒疫霉病菌抑制作不强。 在混施有少量三唑酮和没混施有少量三唑酮的两种辣椒盆栽土中，混施有少量三唑酮的盆栽土中哈次木霉在辣椒植株根际的定殖要比没混施有少量三唑酮的盆栽土中哈次木霉在辣椒植株根际的定殖快。三唑酮可抑制土壤中某些微生物种群，从而加强了木霉在辣椒根际的竞争，以利于引入的木霉在辣椒根际的定殖，达到防治病害的目的。 在使用哈茨木霉生防制剂对辣椒疫霉病进行生物防治的试验中，只施有哈茨木霉的处理与哈茨木霉并混施有少量三哇酮的两个处理结果表现病情指数为0，对辣椒疫霉病防治效果达，100%;只施有三哇酮的处理结果表现病情指数为4，对辣椒疫霉病防治效果达93%.同时有哈茨木霉参加的三个处理中辣椒的株高、茎杆、叶面积和叶片颜色都有明显的优于其它几个处理。使用哈茨木霉并混施有少量三哇酮比只使用哈茨木霉处理中的辣椒植株矮、叶片颜色深、茎杆粗，这可能与三哇酮抑制辣椒生长但能增加辣椒植株的抗逆性有关。 在康氏木霉、拟康木霉与美国康乃尔菌株对辣椒植株的促生作用试验中，辣椒植株在叶片平均面积、植株平均高度以及茎杆的平均周长都显著优于对照。但是美国康乃尔菌株与康氏木霉、拟康木霉相比有更显著的促生作用。更多还原

【Abstract】 Fifty-eight Trichoderma spp. strains were isolated from the capsicum soil in the different depth 5cm and 10cm in ya’an suburb.they were indentified as following species:Tharzianum, T. pseudokoningii, T. citrinoviride, T. atroviride, T. longibrachiatum, T. hamatum, T. koningii,, T. aureoviride.The two Trichoderma isolates were selected and used according to the antagonistic test against Phytophthora capsici .The dominant strains were T. harzianum, T. pseudokoningii, T. koningii.The deeper of the soil located and the higher the soil temperature,the less distribution of Trichoderma spp. were during the capsicum growth.The antagonistic test showed that T.harzianum, T. pseudokoningii* T. koningii had the better antagonistic effects .The inhabition of metabolites against Phytophthora capsici were 69.1%% 67.2%, and 63.6% repectively.The interaction between T.harzianum and hypha of Phytophthora capsici showed that T.harzianum made hypha of Phytophthora capsici dissolved % twisted and distorted. In the end,it led to collapse of hypha.The colonization experiment in potted capsicum soil showed that the colonization of Trichoderma spp. in the soil which were mixed with T. harzianum and triadimefon. quicker than that in the soil only applied T.harzianum. The possible reason is some microorganism in soil was inhabited by pesticide to make T. harzianum colonize quickly.The biological control against Phytophthora capsici with T. harzianum showed that T. harzianum had strongly biological effect on phytophthora capsici .The biological control effect of the treatment of which were mixed with triadimefon and T. harzianum was the same with the treament of which only was used T. harzianum,botii are 100%.But The biological control effect of the treatment in which was only used triadimefon was 93%. At the same time T. harzianum also promoted capsicum growth obvisouly.T. koningii * T. pseudokoningii and The strains which came from Aemerica kangnaier had obvisouly advantage in capsicum growth.But the biological control effect of kangnaier isolate was superiorer than others two.更多还原