水分胁迫对玉米穗位叶叶肉细胞超微结构的影响

Effect of Water Stress on Chloroplast Ultrastructure of Maize

采用盆栽试验,研究了玉米抽雄期后不同灌水量对玉米穗位叶叶绿体超微结构的变化。结果表明:水分亏缺时,玉米叶片叶肉细胞皱缩,细胞的"花环型"结构消失;细胞壁变窄,出现质壁分离现象;叶绿体形状发生变化,从细胞边缘向中央漂移,膜解体破裂;线粒体内外膜和脊模糊,线粒体外膜膨大或破裂;片层结构混乱,基质片层向叶绿体两端拉伸并出现断裂。随着灌水量的增加,叶肉细胞的"花环型"结构清晰可见;细胞壁结构层次清晰,细胞壁的超微结构特征明显;叶绿体外膜逐渐变得清晰,呈长椭圆形或梭形,紧贴细胞壁,被膜清晰;线粒体成规则的圆球形或椭圆形,双层被膜结构完整,内脊清晰;片层增厚,结构逐渐完整且有规律的排列,基粒片层和基质片层清晰可见。综上可见,水分胁迫对玉米生育后期有较大的影响,不同程度地出现了玉米早衰现象,产量明显下降。

The effects of different irrigation amount on chloroplast ultrastructure of maize were studied.The results showed that under water deficit condition,mesophyll cell shrinked,cell ＂garland-type＂structure disappeared;cell wall became narrow,appeared plasmolysis phenomenon;chloroplast shape changed and drifted from the cell periphery to the center,membrane disintegrated;Mitochondrial outer and inner membranes and ridge was fuzzy,outer membrane expanded or split;lamellar structure was chaos,stroma lamellae extruded to the chloroplast ends and split.With the increase of irrigation amount,mesophyll cell ＂garland-type＂ structure is clearly visible;the cell wall hierarchy and ultrastructure characteristics wad clear;chloroplast was gradually clear,with a long oval or spindle shape,close to the cell wall,membrane was clear;Mitochondrion was spherical or oval,double film structure was complete and inner ridge was clear;lamellar thicked,structure was gradually complete and regular arranged,grana and stroma lamellae were visible.Therefore,it was seen that there was influence of water stress at late growth stage in maize,premature senescence appeared and yield decreased significantly under water stress.