供氮水平对番茄苗期Q型烟粉虱成虫种群动态的影响

烟粉虱(Bemisia tabaci)是重要的农业害虫。在栽培管理中,为了减少化学农药的施用,对该害虫采取生态防控措施日益得到重视。以Q型烟粉虱为研究对象,根据温室大棚内9次烟粉虱成虫种群数量调查和番茄苗期5项农艺指标测量,结合主成分分析、线性逐步回归分析及Pearson相关性分析,从"氮素-番茄-Q型烟粉虱"互作角度开展生态防控措施研究,旨在探明番茄苗期的烟粉虱成虫种群发生数量与氮素水平关系。结果表明:3个氮水平(高氮1134 mg·L^-1,标准氮945 mg·L^-1,低氮756 mg·L^-1)下的5个番茄指标(株高、茎粗、叶面积、叶绿素相对含量、叶片全氮含量)最大值基本呈现高氮>标准氮>低氮的规律;调查的9次烟粉虱虫口数量在最大峰值时的高低排序为高氮>标准氮>低氮。主成分分析表明,3种氮素水平下叶绿素相对含量是影响烟粉虱成虫虫口数量的主要因子。线性回归与相关性分析表明,3种氮素水平下的叶片全氮含量、叶绿素相对含量与虫口种群数量相关性较高。氮营养是影响植物和烟粉虱的关键因素之一,高氮水平下番茄长...

Effects of nitrogen level on population dynamics of adult Q-type Bemisia tabaci from tomato seedlings

Bemisia tabaci is a major agricultural pest.To reduce the application of chemical pesticides,it is important to take ecological controlling measures for cultivation management.Here,we investigated five agronomic traits of tomato seedlings and Q-type B.tabaci population for nine times in greenhouses.Our aim was to probe into the relationship of B.tabaci population density from tomato seedlings and nitrogen levels(i.e.,1134 mg·L^-1,high;945 mg·L^-1,standard;756 mg·L^-1,low)by using principal component analysis,linear regression analysis,and Pearson correlation analysis.The results showed that the five traits including plant height,stem diameter,leaf area,chlorophyll relative content,and leaf total nitrogen content followed a similar trend with the order of high nitrogen level>standard nitrogen level>low nitrogen level.The population density of B.tabaci from tomato seedlings at the peak stage for nine times showed the same order of high nitrogen level>standard nitrogen level>low nitrogen level.The results of linear regression analysis and Pearson correlation analysis showed a high correlation between B.tabaci population density and the chlorophyll relative content and leaf total nitrogen content.The results of principal component analysis showed that leaf chlorophyll relative content was the key factor driving B.tabaci population density across nitrogen levels.It was suggested that nitrogen level was one of key factors affecting the growth of tomato and B.tabaci population density:the higher nitrogen level,the better growth of tomato seedlings and the greater density of B.tabaci.Leaf total nitrogen content and chlorophyll relative content were suggested to be the ecological control index to monitor the fluctuation of Q-type B.tabaci population density.