【作者】 刘震；

【导师】 傅俊范；

【作者基本信息】 沈阳农业大学 ， 植物病理学， 2014， 博士

【摘要】 玉米是我国四大粮食作物之一,具有重要的社会和经济效益。玉米纹枯病和玉米大斑病是我国玉米产区主要病害。近年来随着我国东北玉米种植面积的增加和新型栽培模式的推广,玉米纹枯病与玉米大斑病的流行动态出现了新的变化。本论文根据植物病害流行学原理,采用田间试验设计和人工接种技术,明确了双株定向等新型栽培模式下玉米纹枯病与玉米大斑病的流行动态,并在此基础上构建了玉米纹枯病及玉米大斑病流行时间动态模型。本文通过测定不同新型栽培模式玉米冠层温度、湿度等环境因素对病害时空动态的影响,结合土壤温度、含水量、pH对玉米纹枯病菌菌核产生的条件模拟分析了病害灾变机制。本文采用分子生物学研究技术设计了玉米纹枯病菌特异引物,并对玉米植株及土壤内纹枯病菌进行了分子检测。主要研究结果如下：1、本文首次采用比较流行学的方法对玉米纹枯病与玉米大斑病在双株定向等新型栽培模式下的流行动态进行系统研究。研究表明,玉米纹枯病从开始接种到流行末期(2013年9月13日)常规栽培模式、比空栽培模式、大垄双行栽培模式和双株定向栽培模式的病情指数分别为50.0、29.6、41.2和36.2,新型栽培模式之间以及与常规栽培模式之间病情指数存在显著差异,其严重程度：常规栽培模式>大垄双行栽培>双株定向栽培模式>比空栽培模式。2012年田间调查发现,人工接种玉米大斑病,到流行末期9月11日常规栽培模式、比空栽培模式、大垄双行栽培模式的病情指数分别为55.3、43.9和59.9,三种栽培模式之间病情指数存在显著差异,其严重程度：大垄双行栽培模式>常规栽培模式>比空栽培模式。2013年人工接种玉米大斑病到流行末期9月13日,常规栽培模式、双株定向栽培模式和双株紧靠栽培模式的病情指数分别为43.7、35.6和36.4,双株定向栽培模式与双株紧靠栽培模式病情指数差异不显著,其原因是种子的选材不同,种植方法相同。这两种栽培模式与常规栽培模式的病情植株存在显著差异,其严重程度：常规栽培模式>双株紧靠栽培模式≥双株定向栽培模式。2、本文首次系统地研究双株定向等新型栽培模式下玉米纹枯病与大斑病灾变机制。利用温湿度电子记录仪对两个生长季双株定向等新型栽培模式小区进行定时监测,结果表明,2012年常规栽培模式、比空栽培模式、大垄双行栽培模式、双株定向栽培模式的平均湿度分别为87.8%、84.4%、92.6%和82.7%,平均温度分别为23.3℃、22.5℃、24.0℃和22.2℃；2013年常规栽培模式、比空栽培模式、大垄双行栽培模式、双株定向栽培模式的平均湿度分别为94.0%、87.3%、91.8%和87.8%,平均温度分别为24.3℃、21.9℃、23.78℃22.2℃。由监测数据可知,新型栽培模式空间的通透性较强,有效地利用光能,改变小区内的温湿度,可以减缓玉米纹枯病与大斑病的扩散速度,从而降低发病程度。但是,光线对玉米大斑病菌分生孢子的萌发有一定的抑制作用,大垄双行栽培模式作为一种新型栽培模式其小区内局部种植密度大,使空间透光性差,温湿度较高,促进玉米大斑病的扩散速度,从而增加了发病程度。3、本文首次对双株定向栽培模式下玉米纹枯病的空间传播方式进行研究。结果表明,双株定向栽培模式发病植株并非全为离菌源中心最近的植株,没有表现出一定的时间和空间梯度,而呈现随机状态。双株定向栽培模式下玉米纹枯病在单一生长季内不存在空间传播,或传播距离很短,病害较轻。4、本文首次构建了双株定向等新型栽培模式下玉米纹枯病与大斑病流行的单年时间动态模型。通过田间小区设计和人工接种的方法,利用SPSS11.5统计软件进行对比分析,确认了Logistic模型为最佳模型。通过Logistic模型的公式变形可推导出双株定向等新型栽培模式下玉米纹枯病与大斑病单年时间动态的各个流行时期,因此玉米纹枯病与大斑病的指数生长期也是药剂防治最佳时间。5、本文首次利用土传植物病原生态学的试验方法,通过模拟土壤温度、含水量、pH值对玉米纹枯病菌菌核生长和萌发进行研究。研究结果表明,土壤温度对菌核生长和菌丝萌发影响较大,在含水量一定,pH值一定的条件下,25℃下菌核生长和萌发最快,30℃次之。在土壤pH值一定、温度适宜的条件下,土壤含水量对玉米纹枯病菌菌核产生和萌发影响很大,随着土壤湿度的增加,菌核生长出菌丝和萌发的速度越快,这也更能体现该菌适宜高湿的习性。土壤含水量一定、温度适宜的条件下,在中性或略偏酸性条件下菌核生长和萌发速度较快,强酸,强碱都对会对其生长和萌发产生抑制作用。6、本文初步建立了玉米纹枯病菌分子检测体系,为玉米纹枯病的早期诊断和监测奠定了理论基础。该体系在对玉米纹枯病菌ITS区进行PCR扩增、测序及序列分析基础上,设计了特异性引物LZ-F/LZ-R。只有以Rhizoctonia solani基因组为模板的体系中能扩增出一条460bp左右的条带,而其他菌株均无扩增出特异条带。利用该特异性引物能从罹病组织和人工接种R.solani的土壤DNA中扩增出特异性条带,而对健康的玉米组织均无扩增产物,表明该特异性引物可以用于玉米纹枯病的分子检测。更多还原

【Abstract】 Maize which has important economic returns and social benefits is one of the four chief crops in China. Corn Sheath Blight and Corn Northern Leaf Blight are the main diseases of maize producing areas in China. In recent years, epidemic dynamics of Corn Sheath Blight and Corn Northern Leaf Blight have new changes with the increasing of Northeast corn planting area and the promotion of new cultivation model. According to the principles of plant disease epidemiology, this paper definitudes the epidemic dynamics of Corn Sheath Blight and Corn Northern Leaf Blight in the two-plant orientation cultivation mode by using field experimental design and artificial inoculation technique, on the base of which, constructs the epidemic dynamic model of Corn Sheath Blight and Corn Northern Leaf Blight. This paper simulates and analyzes the disease catastrophe mechanism, by measuring the corn canopy temperature, humidity and other environmental factors on the temporal and spatial dynamics of disease in the different model cultivation model, combining with the soil temperature, water content, and pH on Corn Sheath Blight sclerotium producing conditions. Using molecular biology technique, this essay designs the specific primer of Corn Sheath Blight which detects the Rhizoctonia solani in maize plants and soil. The main results are as follows:1. The epidemic dynamics of Corn Sheath Blight and Corn Northern Leaf Blight in the two-plant orientation cultivation mode and other new modes had been researched for the first time with Comparative Epidemic Science. Researched shows that the disease index of Corn Sheath Blight in the conventional cultivation pattern, two-one row interval cultivation mode, mulching two lines cultivation mode and the two-plant orientation cultivation mode from the beginning of being inoculated to the end of prevalence (September13,2013) are50,29.6,41.2and36.2, and there is significant difference among the above four modes, whose severity was conventional cultivation mode> mulching two lines cultivation mode> two-plant orientation cultivation mode> two-one row interval cultivation mode. It was found that the disease index of Corn Northern Leaf Blight in the conventional cultivation pattern, two-one row interval cultivation mode and mulching two lines cultivation mode from the beginning of being inoculated to the end of prevalence (September11,2012) are55.3,43.9and59.9, and there was significant difference among the above three modes, whose severity is mulching two lines cultivation mode> conventional cultivation pattern> two-one row interval cultivation mode. The disease index of Corn Northern Leaf Blight in the conventional cultivation pattern, the two-plant orientation cultivation mode and two-plant abuts cultivation mode from the beginning of being inoculated to the end of prevalence (September13,2013) are respectively43.7,35.6and36.4. The disease index in the two-plant orientation cultivation mode and two-plant abuts cultivation mode were not significantly different, the reason of which was the different seed materials in the same planting method. There was a significant difference between above two modes and conventional cultivation pattern, whose severity was conventional cultivation pattern> two-plant abuts cultivation mode> two-plant orientation cultivation mode.2. This was the first study on the catastrophe mechanism of Corn Sheath Blight and Corn Northern Leaf Blight in the two-plant orientation cultivation mode and other new cultivation modes. The two growing seasons of experimental districts in the two-plant orientation cultivation mode and other new cultivation modes was regularly monitored by the electronic temperature and humidity recorder, which shows that the average humidity in the conventional cultivation pattern, two-one row interval cultivation mode, mulching two lines cultivation mode and the two-plant orientation cultivation mode in2012were87.8%,84.4%,92.6%and82.7%, and the average temperature were23.3℃,22.5℃,24℃and22.2℃. In2013, the average humidity were respectively94.0%,87.3%,91.8%and87.8%,and the average temperature are respectively24.3℃,21.9℃,23.7℃and22.2℃. It’s showed from the monitoring data that more permeability in the new cultivation modes, effectively using light and changing the temperature and humidity in the districts have slowed the diffusion rate of Corn Sheath Blight and Corn Northern Leaf Blight and reduced the incidence degree.3. This paper studies space communication of Corn Sheath Blight in the two-plant orientation cultivation mode for the first time. The results show that the diseased plants are not all the nearest to the bacteria source center in the two-plant orientation cultivation mode, which show no temporal and spatial gradients of certain, but present random state. A single growing season of Corn Sheath Blight in the two-plant orientation cultivation mode doesn’t have space transmission, or its transmission distance is very short and the disease degree is light.4. This paper proposes a single year dynamic model of Corn Sheath Blight and Corn Northern Leaf Blight in the two-plant orientation cultivation mode and other new cultivation modes for the first time. It has confirmed that the Logistic model is the best model through field experimental design and artificial inoculation technique, which is analyzed by SPSS11.5statistical software. Every epidemic period in the single year dynamic of Corn Sheath Blight and Corn Northern Leaf Blight in the two-plant orientation cultivation mode and other new cultivation modes can be deduced from the Logistic model deformation, therefore the exponential growth phases of Corn Sheath Blight and Corn Northern Leaf Blight are also the best time of chemical control.5. The sclerotium growth and germination of Corn Sheath Blight whose soil temperature, moisture content, pH are simulated has been studied by test method of soil borne plant pathogen ecology for the first time. The results show that the soil temperature has great effect on sclerotium germination and mycelium growth of Corn Sheath Blight, which at25℃under certain moisture content and pH was fastest and at30℃was the second. Soil moisture content has great influence on sclerotium formation and germination of Corn Sheath Blight under certain pH and appropriate temperature. The mycelium growth and sclerotium germination speed more quickly with the increasing of soil moisture, which can reflect the habit of being suitable for high humidity. Under certain soil moisture and appropriate temperature, neutral or slightly acidic conditions are suitable for the growth and germination, and strong acid and strong alkali can inhibit.6. This paper establishes the molecular detection system of Corn Sheath Blight, which provides the theoretical foundation for the early diagnosis and monitoring. This system designs the specific primer LZ-F/LZ-R for Corn Sheath Blight, which was based on PCR amplification, sequencing and sequence analysis of ITS region. Only in the Rhizoctonia solani genome is amplified a band about460bp template system, and the other strains have no specific bands. Specific bands can be amplified by using the specific primers from soil DNA infected tissue and artificial inoculation of R.solani, but there is no amplification product from the health of the corn tissues, which shows that the specific primer can be used for molecular detection of Corn Sheath Blight.更多还原