【作者】 周青；

【导师】 谢关林；

【作者基本信息】 浙江大学 ， 植物保护， 2013， 硕士

【摘要】 十字花科蔬菜根肿病是由芸薹根肿菌(Plasmodiophora brassicae)引起的一种世界性土传病害,造成十字花科作物的大量减产,严重制约油料和蔬菜产业发展。为更好地利用生物防治的方法控制根肿病,本研究通过离体和温室筛选,得到4株具有良好防效的菌株：Y9,Y16,Y26和Z4。经菌落形态等细菌学特征观察、Biolog鉴定、脂肪酸测定(FAMEs)及16S rDNA序列分析,将该菌株鉴定为Bacillus megaterium Y9, Pseudomonas putida Y16, Staphylococcus chromogenes Y26和Microbacterium-barkeri Z4,并选择B. Megaterium Y9研制成·相关种衣剂。种衣剂检测试验表明,种衣剂干燥速度快,成膜性好,又不易溶胀,其防治效果达62%。种子包衣以后能提高种子发芽率,增强种苗长势,生防菌在种衣剂中的存活力也较强,一年后仍达3×106CFU/mL。本研究利用超声波将壳聚糖和纳米Ti02按一定浓度比例配制成壳聚糖／纳米Ti02复合材料,增强了壳聚糖的抑菌效果,并通过促生、温室防效试验筛选出防治十字花科根肿病的最佳浓度(0.10/0.50mg/mL)。利用傅里叶红外(FT-IR)检测技术壳聚糖／纳米Ti02复合材料,结果表明壳聚糖／纳米Ti02复合材料没有改变壳聚糖的原有结构,只通过氢键使壳聚糖与纳米Ti02紧密结合。传统方法很难准确检测根肿菌,本研究中利用FT-IR发现了感染根肿菌的植物组织所具有的特征峰。这些特征峰为利用FT-IR快速、定性鉴定植物组织是否感染芸苔根肿菌提供了依据。同时,利用Real-time PCR建立了浙江省根肿病样本定量检测方法。其扩增效率为112%,检测范围从104-108个/g。更多还原

【Abstract】 Cruciferous clubroot caused by the obligate endoparasite Plasmodiophora brassicae, is recognized as a world-wide serious soilborne disease, associated with appreciable losses of cruciferous crops and hampered the development of oil and vegetable industry. To make better use of biological control of the clubroot,4antagonistic bacterial strains against P. brassicae have been screened out based on vitro and greenhouse tests, which were identified as Bacillus megaterium Y9, Pseudomonas putida Y16, Staphylococcus chromogenes Y26和Microbacterium barkeri Z4by colony morphology, major bacteriological characteristics, Biolog identification, fatty acid methyl esters analysis(FAMEs) and16S rDNA sequence analysis. B. megaterium was developed into seed coating reagent, which could increase seed germination rate and enhance seed vigor. The test results showed that the seed coating reagent had quick drying speed, good membrane property and low swelling rate and its control effect reached62%. The survival rate of Bacillus megaterium Y9on the seeds was relatively high and its concentration was3×106CFU/mL after one year storage.In this study, chitosan/nano-TiO2composite was prepared at the most appropriate concentration ratio (0.10/0.50mg/mL) of chitosan and nano-TiO2. It could enhance the inhibitory effect of chitosan. The Fourier Transform Infrared Spectroscopy (FT-IR) result showed that chitosan/nano-Ti02composite did not change the original struture of chitosan, but closely combined through hydrogen bonds.For traditional method is difficult to accurately detect P. brassicae, we found special peaks of plant tissue infected with P. brassicae based on FT-IR. According to these special peaks, we can identify whether plant tissues have been infected by P. brassicae with the use of FT-IR. Moreover, a Real-time PCR quantitive detection model established was to detect clubroot samples collected in Zhejiang Province. Its amplification efficiency was112%and dectection range was from104-108spores/g.更多还原