【作者】 刘娜；

【导师】 龚国淑；

【作者基本信息】 四川农业大学 ， 植物病理学， 2010， 硕士

【摘要】 小麦白粉病是由小麦白粉菌(Blumeria graminis f. sp. tritici)引起的小麦生产上的重要气传病害。小麦白粉菌是高度专性寄生菌,所以小麦白粉菌的越夏情况及其夏季寄主是影响白粉病发生与流行的关键因子。为了明确四川省小麦秋苗的初侵染源及其越夏区域,本试验对四川省小麦白粉病菌闭囊壳的越夏、自生麦苗上分生孢子的越夏及其夏季寄主小麦的存活状况进行了初步研究,了解了小麦白粉菌及其寄主在四川省夏季的生存情况。并且为了能进一步弄清四川省小麦白粉菌的流行规律,本试验在2008和2009年度对川农26和川育20两个小麦品种进行了白粉病发生情况的系统调查,根据小麦白粉病病情指数、平均严重度、普遍率随时间变化的规律,系统分析了四川省雅安市小麦白粉病发生流行的时间动态及流行趋势。本文通过对四川省小麦白粉病越夏研究,发现小麦白粉菌在四川省海拔600 m以上区域(含600m)可以顺利越夏,成为秋苗的初侵染源。在四川全省自生麦苗调查中发现夏季自生麦苗可在四川省多处地方存活,且少数地区自生麦苗感染白粉病。在雅安四川农业大学农场进行了自生麦苗系统观察,观察到农场的夏季自生麦苗数量多、发病严重,且高遮阴作物较矮遮阴作物更有利于自生麦苗存活和发生白粉病,其中部分自生麦苗可带菌存活至小麦秋播期,为小麦白粉病的发生流行提供了有利的条件。闭囊壳存活率和成孢率镜检试验结果表明存放于室内,屋檐下以及干燥器中的闭囊壳可以存活度过夏天。同时,通过隔离试验证实夏季存放的闭囊壳可以度过夏天并成功侵染麦苗发生白粉病。观察2008和2009两年度小麦白粉病时间流行动态,结果表明小麦白粉病的普遍率,病情指数,严重度时间进程曲线都呈近似的“S”型曲线。用SPSS软件对2009年度川农26发生小麦白粉的普遍率,平均严重度,病情指数进行逻辑斯蒂曲线和S型曲线拟合,结果显示,以逻辑斯蒂曲线拟合普遍率的拟合效果最好,R2=0.924；川育20以逻辑斯蒂曲线拟合病情指数的拟合效果最好,R2=0.968。从2008和2009两年度小麦白粉病的病情来看,2009年度的始见病株时间比2008年度早。由两年度的整体趋势可以得知,川农26发病的严重程度明显高于川育20。对比两年的试验结果,小麦白粉病两年的流行动态有明显的差异。虽然每年小麦白粉病病情的普遍率最高都达100%,但是每年的病情指数与平均严重度都不同。从表观侵染率来看,表观侵染率在每年相同时间内的动态变化都不同,但是通过这两年的试验观察可以得出相同的结果是,表观侵染速率与病情指数增长呈正相关关系。更多还原

【Abstract】 Wheat powdery mildew which is an important product atmospheric disease is caused by Blumeria graminis f. sp. tritici. B. graminis f. sp. tritici is a powerful, specific obligate parasite. Therefore, the over-summering of the pathogen and the summer host are the key factors which affect powdery mildew incidence and prevalence. In order to clarify the primary infection source and its over-summering areas of wheat seedlings in Sichuan Province, the over-summering of cleistothecium and conidia from volunteer wheat seedlings, also the survival condition of its summer host (wheat) in Sichuan Province were studied. And the living conditions of the pathogen and its host in the summer in Sichuan Province were clarified. In order to further clarify the epidemic regularity of wheat powdery mildew in Sichuan Province, we had a systematic survey of the wheat powdery mildew occurrence of Chuanyu20 and Chuannong26 in 2008 and 2009. According to powdery mildew disease index, average severity, prevalence rate of the variation over time, the occurrence and epidemic dynamics of wheat powdery mildew in Yaan were analyzed.The result showed that the pathogen of wheat powdery mildew over-summered at an altitude of 600 meters sea level (include 600 meters) in Sichuan Province and then to infect the wheat in autumn. In the investigation on the volunteer wheat seedlings in Sichuan Province, there were a lot of summery wheats in many areas and some of the wheat occurred powdery mildew. Systematic observation of the wheat in the farm of Sichuan Agriculture University in Yaan was made and what was observed was that the summery wheat existing in great quantity and the morbidity rate was really high, what can even be found was that high-shady crops were more easily affected by powdery mildew than shorter ones, some of them could become carriers to survive until fall seeding stage which providing popular of wheat powdery mildew. The survival and spore of the cleistothecium researching by microscopy showed that the cleistothecium store indoors, under the eaves, and the dryer can survive through the summer. At the same time, the storage cleistothecium could through the summer and successful infect wheat to powdery mildew were confirmed through isolation experiments. The temporal dynamics of wheat powdery mildew in 2008 and 2009 showed that the general rate, disease index, the severity of the approximate time curve of wheat powdery mildew were tested "S" curve. Using SPSS software conducted logistic curve and S-curve fitting of the general rate, the average severity and the disease index of wheat powdery mildew which Chuannong26 occurred in 2009, the results showed that the logistic curve fit to the average severity was the best fitting, R2=0.924, and the logistic curve fit to the disease index was the best fitting for Chuanyu20, R2=0.968. The disease of wheat powdery mildew in 2008 and 2009 showed that the beginning to see the diseased plant in 2009 is earlier than 2008. The severity of disease in Chuannong26 was significantly higher than Chuanyu20 were studied from the overall trend in these two years. The results of two years were comparatived, it showed that there were significant differences in the dynamic of wheat powdery mildew epidemic each year. Although the wheat powdery mildew disease had the highest general rate of 100% each year, but the disease index and the average severity were significantly different. As can be seen from the apparent infection rate, although the dynamic changes of apparent infection rate were different at the same time each year, but the experiment in these two years had the same result can be drawn is that the apparent infection rate and the disease index showed a positive correlation between growth.更多还原