Conductance Of Several Chemical Elements In Rice Plant-Brown Planthopper (Nilaparvata Lugens St(?)l) System And Their Physiological Effect

This study investigated conductance of several chemical elements in rice plant-N. lugens system by manipulating concentrations of Cu,Fe,Mn and Zn elements in hydroponic experiment,and effects of several chemical elements on N.lugens and rice plant after N.lugens infestation.Results are as follows:1.Conductance of several chemical elements in rice plant-N.lugens system under We mensured contents of Na,Mg,K,Ca,Zn,Mn,Fe and Cu in rice plant,sap bleeding of stem,N.lugens and honeydew using inductively coupled plasma atomic emission spectrometry.The results showed that contents of Zn,Mn,Fe and Cu in rice plant increased with increase of their concentrations in hydroponics solution.More interestingly,the increase of these four elements in hydroponics solution changed the content of other chemical elements in rice plant,either positively or negatively.For example,the content of Na increased significantly when concentrations of Zn and Cu was elevated(for Na-Zn:r＝0.99,P＜0.01 and for Na-Cu:r＝0.97,P＜0.01).In contrast,the content of Mg decreased significantly with concentrations of Zn,Mn and Fe(for Mg-Zn:r＝-0.94,P＜0.05;for Mg -Mn:r＝-0.82,P＜0.05 and for Mg-Fe:r＝-0.97,P＜0.01).Moreover,some of elements in rice plant were transferred to sap bleeding of stem,N.lugens and honeydew.For example,Na was conducted between rice plant and N.lugens in the manipulation of Zn and Cu(for Na-Zn:r＝0.98,P＜0.05; for Na-Cu:r＝0.98,P＜0.05),and Ca did between sap bleeding of stem and N.lugens when Cu was increased in hydroponics solution(r＝0.88,P＜0.05).While Mg had a negative correlation between rice plant and N.lugens body when the concentration of Zn in hydroponic solution was increased(r＝-0.91,P＜0.05).Among the four chemical elements manipulated in the hydroponics solution,only Mn was transferred to rice plant-N.lugens system(r＝0.88,P＜0.05).When the concentration of Mn in hydroponics solution was elevated,the content of Mn in rice plant,sap bleeding of stem, and N.lugens body was increased.2.Effect of chemical elements on physiology and chemistry of N.lugens and rice plant after N.lugens infestationWe mensured growth index(root length,root-leaf ratio and root vigor) and physiological index(chlorophyll content,activity of protection enzymes) of rice plants, and biochemical changes of N.lugens body under manipulation of concentrations of several lements in hydroponics solution.Results are as follows:There were significant differences in growth indices of rice plants between different gradient concentrations of Cu,Fe,Mn and Zn elements in hydroponics solution.For example,there was significant difference in root length between different gradient concentrations of Fe and Cu,root-leaf ratio between different gradient concentrations of Mn,Fe and Cu,root vigor between different gradient concentrations of Cu,Fe,Mn and Zn.There were no significant differences in physiological indices of rice plants between different gradient concentrations of Cu,Fe,Mn and Zn.However,after N.lugens infestation,physiological responses of rice plants were significantly affected.For example,N.lugens infestation reduced plant chlorophyll content significantly.There was significant difference in SOD activity between rice plants after N.lugens infestation and control plants under different gradient concentrations of Zn and Fe.N.lugens infestation elevated SOD activity under normal hydroponics solution,but SOD activity declined under other concentrations conditions.In addition,N.lugens infestation reduced PPO activity of rice plants.There was significant difference between different gradient concentrations of Cu.Physiological indices of N.lugens changed after infestating rice plants.There were significant differences on SOD and POD activities of N.lugens under different gradient concentrations of Zn,Mn and Fe.Low concentrations of Zn,Mn,Cu increased SOD and POD activities.There was a significant difference in CaE activity of N.lugens under different gradient concentrations of Mn and Cu.Low concentrations of Mn and high concentrations of Cu increased CaE activity.GST activity in N.lugens from fed on rice-plant under different gradient concentrations of Zn, Mn,Fe and Cu was significantly different.