Influences of Pest Mite Stress on Cell Ultrastructure and Free Proline Content of Fuji Apple Leaves

Zhang Kunpeng; Sun Ruihong; Yang Hongqiang

doi:10.14083/j.issn.1001-4942.2016.06.009

Abstract：To explore the effects of Tetranychus viennensis,Tetranychus urticae and Panonychus ulmi on cell ultrastructure and Tetranychus viennensis on free proline content of Fuji apple leaves,the cell ultrastructure changes of leaves infested by 3 kinds of pest mites for 6 days were observed with transmission electron micro-scope,and the free proline content was determined using acid ninhydrin method.The results showed that,in the normal Fuji apple leaves,the cells presented rectangle with clear border and arranged in line with the sim-ilar size.The organelles distributed orderly in cytoplasm.There were many boat shaped chloroplasts scattered along cell wall.The nucleus presented long elliptic with clear nucleoli and karyotheca.The cell membrane and wall were intact,and the walls between adjacent cells were clearly viewed.The cell structure of Fuji apple leaves were seriously destroyed after infestation of pest mites.The intercellular space increased,the changes of chloroplasts and nucleus were also observed,and the starch granules appeared inner the chloroplasts,so the cell functions were severely affected.The needle crystal was observed near the cell wall of Fuji apple leaves infes-ted by Tetranychus viennensis.The free proline content increased firstly and then decreased on the whole with the increase of time and population density of Tetranychus viennensis.Above all,the pest mite harms would destroy the cell ultrastructure of Fuji apple leaves,which further caused cell function loss,and the increase of free proline content indicated the confrontation of Fuji apple leaves to feeding of Tetranychus viennensis.