【作者】 孙燕；

【导师】 姜兴印；

【作者基本信息】 山东农业大学 ， 农药学， 2013， 硕士

【摘要】 近年来，由亚粘团镰孢霉（Fusarium subglutinans）引起的玉米顶腐病是我国玉米生产上的一种新病害。目前，国内外对玉米顶腐病的研究较少，缺乏系统的研究和有效的防治措施。本研究论文通过室内毒力试验筛选出抑制亚粘团镰孢霉菌丝生长的高效杀菌剂，分析了不同浓度的毒素滤液对玉米胚根和胚芽生长的影响，明确了亚粘团镰孢霉作用寄主的最初部位，为初步探明亚粘团镰孢霉对玉米植株的致病机制奠定基础，同时通过大田试验进一步明确了顶腐病对玉米植株光合特性、叶绿素含量、根系活力及保护酶活性的影响，为生产上对该病害发生程度的快速调查、产量损失预测及科学防治提供一定的理论依据。1.室内采用菌丝生长速率法，分别测定7种杀菌剂对亚粘团镰孢霉的抑菌效果。结果表明：咯菌腈的EC50最小，病原菌对它的敏感性最高，抑菌效果最好；戊唑醇和多菌灵的EC50较小，病菌对它们的敏感性也较高，抑菌效果也较好。2.通过温室种子包衣试验，研究了25g/L咯菌腈悬浮种衣剂、60g/L戊唑醇悬浮种衣剂和80%多菌灵可湿性粉剂对于玉米顶腐病的控制效果。结果表明：玉米种子经药剂拌种后出苗率显著增加，经咯菌腈处理后，玉米种子出苗率最高，防治效果也最好；戊唑醇次之，多菌灵防治效果不太明显。建议生产上可使用25g/L咯菌腈悬浮种衣剂和60g/L戊唑醇悬浮种衣剂来防治玉米顶腐病。3.通过室内毒素平皿培养进一步明确了亚粘团镰孢霉对玉米种苗的致病机制。结果表明：由亚粘团镰孢霉产生的毒素对玉米种子胚根和胚芽的生长具有明显的抑制作用并且毒素滤液对于胚根生长的抑制作用明显高于胚芽，反映了在玉米顶腐病发生中，寄主根系是毒素最初的作用部位。玉米种子经咯菌腈拌种后，加入不同浓度的粗毒液，胚根、胚芽的生长最好，其对亚粘团镰孢霉的抑制效果最好，其次为戊唑醇，多菌灵抑菌效果低于前两者。4.通过2年的人工定量接菌的田间小区试验，研究了幼苗期、大喇叭口期、灌浆期和成熟期四个生育时期顶腐病对玉米植株光合特性、叶绿素含量、根系活力及保护酶和产量的影响。结果表明：夏玉米叶片受到顶腐病危害后，对其光合特性、叶绿素含量和根系活力均具有一定的影响，其超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）等抗逆酶的活性明显下降，并且病害危害越重，其活性越低。玉米种子经咯菌腈、戊唑醇和多菌灵不同浓度拌种处理后，相较对照，随药剂处理浓度增加对玉米保护作用增强，对玉米顶腐病防效提高，对产量促进作用增大。更多还原

【Abstract】 In recent years, the corn top rot caused by Fusariurn subglutinans is a new disease onmaize production in China. At present, there are seldom domestic researches and systemresearch reports or effective measures against the disease. Through the indoor toxicityexperiment, screened the effeccient fungicides which can inhibit the growth of Fusariurnsubglutinans, analyzed the different toxins filtrate effects on corn radicle and germ growth,further defined the initial site where Fusariurn subglutinans effccts the parastisu, lay thefoundation for preliminary proved the the pathogenic mechanism usariurn subglutinans on themaize plants. At the same time, further cleared the effect of the corn top rot on photosythesischaracter, chlorophyll content, root activity and protective enzymes through field tests,providing theoretical basis for quick survey of the disease forcast of yield loss and scientificprevention.1. The growth rate method was used to determine the inhibition effect of7fungicides onFusariurn subglutinans was measured. The results showed that the EC50of fludioxonil wasthe smallest. The sensitivity of pathogen to this fungicide was the highest, and its inhibitoryeffect was best. The EC50of tebuconazole and carbendazim were smaller, the sensitivity ofpathogen to them was higher, and their inhibitory effect was better.2. The control effect of25g/L fludioxonil FS,60g/L tebuconazole FS and80%carbendazim WP corn top rot was measured though corn seedlings experiment in greenhouse.The results showed that corn seeds’ by the medicament treated which germination rateshowed a significant increase. Corn seeds which by the25g/L fludioxonil FS treated,its’germination rate was the highest and the control effect was best. Its’ germination rate andthe control effect by the60g/L tebuconazole FS treated were smaller and the control effect of80%carbendazim WP were worst. The greenhouse seed coating suggested that the25g/Lfludioxonil FS and60g/L tebuconazole FS could be applied in the control of the corn top rot.3. At the same time, the indoor toxicity experiment research has further defined thepathogenic mechanism of Fusariurn subglutinans to maize seedings. The results showed thattoxins produced by the Fusariurn subglutinans on corn radical growth had more obviousinhibitory effect than on corn germ growth. The phenomenon reflected the initial position where toxins came into play was the parastism’ root. Corn seeds which by the25g/Lfludioxonil FS treated, to join different concentrations of toxin filtrates, the growth of radicleand embryo were best and the control effect against Fusariurn subglutinan was highest. Its’the growth of radicle and embryo and the control effect by the60g/L tebuconazole FS treatedwere smaller and the control effect of80%carbendazim WP were worst.4. Field trials of quantitative artificial inoculation about2years were conducted toascertain the effects of photosythesis character, chlorophyll content, root activity, protectiveenzymes activities and yield of summer maize at seedling stage, big bell mouth stage, fillingstage and ripening stage. The results showed that the photosynthetic characteristics andchlorophyll content and root activity of the corn top rot were influenced certainly, and theSOD, POD and CAT activity of which were reduced significantly. The results showed that,with concentrations increasing between different treatment of fludioxonil, tebuconazole andcarbendazim, strengthen the corn protection, improve the control effect, promoting the effectof yield increase compared with the control.更多还原