The Analysis Of Mineral Elements With Geographical Features In Nilaparvata Lugens (St(?)l), And Their Relationships With Chemical Elements In The Environment

The brown planthopper, Nilaparvata lugens (Stal) is a long-distance migration of insect that is considered as a rice pest in Asia, and is also the most serious pest on rice in Yangtze-Huaihe River Basin, South and Southwest China. It is threatening the growth of rice badly, and bringing about the reduction of rice output significantly, and resulting in serious loss of agricultural economy. The aim of this study was to determine and analyze the content and feature of chemical elements in Nilaparvata lugens (N. lugens) from different regions of China by ICP-MS, and to compare the changes in chemical element concentrations in the soil-rice plant-N, lugens system. The geographical variations and correlation of chemical element contents in the soil-rice plant-N, lugens system were analyzed by analysis of variance of general linear mode and correlation analysis respectively. The study discusses on the relationships between chemical elements and N. lugens from different geographical population as well select the key index of the geographic characteristics. The data were evaluated using linear discriminant analysis, which allowed classification and discrimination of the N. lugens samples from different geographical population, to provide a basis for future research on tracking long-term migration route of N, lugens. The main results are as follows:1. The chemical elements of N. lugens, rice plant and soil samples were quantitatively determined by ICP-MS. The chemical element contents in the body of N. lugens were 0.15 ug/kg to 2.21 g/kg, Mg was quantitatively the most abundant element in the N. lugens samples. The chemical element data of N. lugens, rice plant and soil were conducted to analyze the regional differences in statistical test by analysis of variance of general linear mode. The results showed that the chemical elements of rice plant samples, including Sr,Hg,As,Mg,Ca,Zn,Ni,Sb,Co,W,Cs,Pb,Fe,Ba,Rb and Mn, have significant differences among the different regions (p<0.05). The results of soil samples showed that significant differences among the different regions for the 31 chemical elements (p<0.05), except Zr. The results of N. lugens samples also showed that significant differences among the different regions for the 24 chemical elements, which consisted of Cd,As,Rb,Be,Mn,Gd,Sr,Cu,Ag,Mg,Sm,Ti,Cs,Pr,Nd,Mo,Zr,La,Al,Ga, Ba,Pb,Th and Ce (p<0.05). These elements could be used as a characteristic of geographical fingerprint.2. The 29 element content data of N. lugens, rice plant and soil samples from different regions were analyzed by correlation analysis method. The results showed that the concentrations of Pb,As,Be,Cd,Rb,Cs,Ti,Co,Ba and Zr, were significant positive relationship between the soil-rice plant system, as well as the rice plant- N. lugens system. The chemical element contents were significant positive relationship between the soil-rice plant- N. lugens system, which consisted of Pb,As,Cd,Rb and Cs. The soil pH value was significant negatively with the concentrations of Be,Fe,As,Pb,Co,Rb,Cs, except for Mn,Mo. To varying degrees, the concentrations of chemical element in rice plant samples may be effected by soil pH.3. In this study, the chemical element data of N. lugens samples from the nine different regions in 2009 was analyzed by stepwise discriminant analysis, and 15 important elements were selected. The discriminant power in succession were Cd,Rb,Mg,Mn,Mo,Ag,Cu,Be,Cs,As,Ba,Ti,Ga,Zr and La. The discriminant functions were established according to the data of these element contents for the prediction and verification of the known samples, the results showed that the overall classification success was 96.2%. The data of N. lugens samples from the seven different regions in 2008 were also analyzed by linear discriminant analysis, and the traceability index were V,Mn,Fe,Se,Mo,Cd,Ce and Nd, respectively. The discriminant functions were established according to the data of eight trace element contents, the results revealed that the overall classification success was 96.2%.The study reveals that some chemical elements have significant differences characteristics in the rice plant, the soil and Nilaparvata lugens from different geographical population, and preliminary study on the relationship of chemical elements in the soil -rice plant -Nilaparvata lugens system. The kinetic model should provide significance reference for studies of other migrating insect and its geochemical environment.