【作者】 周艳玲；

【导师】 刘学敏；

【作者基本信息】 东北农业大学 ， 植物病理学， 2002， 硕士

【摘要】 在室内控制条件下模拟土壤温度（ST）和土壤含水量（SW）对辣椒疫病菌侵染的影响，通过系统观测分析田间辣椒疫病流行动态，测定甲霜灵与福美双及其混剂对辣椒疫病菌的毒力。研究结果如下： 1．辣椒疫病的发生程度与接种体孢子囊密度密切相关，其ID-DI曲线可用抛物线描述：DI=0.1090+0.03787×ID+0.0002794×ID²。 2．土壤温度和土壤水分状况是决定辣椒疫病菌侵染的重要因子，病菌侵染的最适土壤温度为22℃～28℃，最适土壤含水量为40％或土壤水分基质势值（Ψm值，简称MP）为0（土壤接近饱和）； 发病率（Ⅰ）与ST和SW之间的关系用模型SORT（Ⅰ）=-1.4304-0.03107×SW+0.1467×ST-0.003112×T²-0.0003614×SW²-0.000000051×T²×SW²描述。 3．分析土壤水分基质势（MP）与土壤含水量（SW），发现它们之间关系可用负指数模型描述：MP=459.516×exp（-0.116×SW）。 发病率（Ⅰ）与ST和MP之间的关系可描述为：SQRT（Ⅰ）=-0.6908-0.01544×MP+0.1433×ST-0.003090×ST²+0.0002083×Mp²，相关性检验证明，土壤水分基质势与病菌侵染的关系更为密切。 4．调查辣椒疫病田间流行趋势，发现病害随时间呈现Gompertz增长，DI=exp（-5.088×exp（-0.024×D））； 辣椒疫病与初始病情、多种环境因素间呈线性关系，其关系模型可描述为：Gompit （Ⅰ）=-0.04554+0.9526×Gompit（I₀）+0.05484×T+0.00003789×SW²×ST-0.00009250×SW×ST； 土壤含水量是病害发生的重要环境因素，灌溉频率高导致土壤含水量高，最终发病率也高。田间病害的传播方向与灌溉水流方向一致，呈椭圆形分布。 5．甲霜灵与福美双及其混剂对辣椒疫病菌的毒力测定结果表明，当甲霜灵和福美双以70:30的比例混合时，增效作用最大，增效比为3.18，接种试验也证明其具有良好的防治作用。更多还原

【Abstract】 We simulated the influence of soil temperature (ST) and soil water content(SW) oninfection of P caPsici in controlled climatic chamber, analyzed epidemic dynamics ofphytophthora blight of pepPer by systematic observation in fields, and bioassayed toxicity ofmetalaxyl, thiram and their mixtUres to P caPsici. The resultS were summarized as fOllows1 Disease index of phytophthora blight of pepper correlated with inoculum sporangiadensity ItS ID-DI curve was described with parobola model: DIso.l090ro.03787 xlD+0.0002794 x ID2.2 Soil tempefatLlfe and soil water content were key factors to influence infection of PcaPsici. For each SW disease index increased up to optimum ST(22C~28C) and thendeclined .On the other hand, fOr each ST,disease index increased up to optimum SW(40%)(soil water-matric pOtential was 0,and soil was near to satUration )and then declined.Quantitative analysis showed that the relationship betWeen incidence(I) and ST, SW wasdescribed with the model: SQRT (I ) =-l.4304-0.03107 X SW+0.l467 X ST-0.0031l2 XT2-0.0003614 x SW’-0.00000005l x T2 x SW’.3 Analyzed MP(soil water-matric potential,Wm) and SW we fOund that the relationshipbetWeen them was described with negative exPOnential model f MP=459.5l6 X exp(-0. l 16 Xsw).The relationship between I and ST, MP was described with the model: SQRT (I)=-0.6908-0.0l544 x MP+0. I 433 x ST-0.003090 x ST2ro.0002083 x MP2.4 Observed epidemic dynamics of phytophthora blight of pepper in fields, resultS showedthat GompertZ model was the best one fOr describing disease progress trend: DI=exp (-5.088X exp(-0.024 X D) ).Used primary incidence(Io), SW ST and T to forecast disease index of pepper blight infields, the forecasting model as follows: Gompit (I ) =-0.04554+0.9526 X Gompit(Io)+0’05484x T+0.00003789 x SW2 x ST-0.00009250 X SW x STSW was key factor on disease. SW was higher in plOt where itrigation was more frequent,which resulted in more serious final incidence. In fieIds, the direction of disease spread wasthe same with the inigation water fiowed, disease distribution was ellipse in shaPe.5 Quantitative bioassay toxicity of metalaxyI, thiram and their mixtUres to P caPsici.Results showed that the mixture of them in 70:30 ratio had the best synergistic interaction, synergistic ratio (SR) was 3.18. The inoculation test also illustrated the mixtures effectively controlled the pepper blight by P. capsici.更多还原