高温干旱胁迫下三个多年生黑麦草品种叶绿体和线粒体超微结构的变化

以多年生黑麦草的3个草坪型品种爱神特、百舸和球道为试验材料,研究了在高温和干旱胁迫下,各品种叶肉细胞叶绿体和线粒体等超微结构的变化情况。结果表明,35℃连续高温胁迫下3个品种的叶绿体均膨大变圆,并向细胞中央靠拢,且叶绿体内部分布有一定数目的脂质球体;PEG-6000(w/v)溶液(浓度为25%)处理的干旱胁迫下以球道的叶绿体结构受干旱胁迫伤害程度较重,出现基粒和被膜轻度破损,片层膨胀分化或溶解消失。高温干旱胁迫下3个品种的线粒体形态变化不甚显著,但其数量均有所增加,且3个品种叶肉细胞线粒体对高温干旱胁迫的耐受性均强于叶绿体。爱神特对高温干旱胁迫处理的耐受性相对较强,球道和百舸的耐热抗旱性较弱,但两者差异不明显。

Alterations in leaf cellular ultra-structure of three varieties of Lolium perenne subjected to high temperature and soil drought stress

Changes of leaf cellular ultra-structure in response to high temperature and drought stress in three varieties (Accent, Bartwingo and Fairway) of Lolium perenne were investigated. Under high temperature stress of 35℃ chloroplasts swelled, became round and moved centrally. There was some plastoglobulis within the chloroplasts. The chloroplasts of Fairway under drought stress from 25% PEG-6000 solution were badly damaged. Their grana and envelope disrupted and the lamella swelled, split, and even dissolved and disappeared. The morphological variation of the mitochondrion was not distinct and their number increased under high temperature and soil drought stress. Compared with chloroplasts, the mitochondrial tolerance and resistance to high temperature and drought stress were strong. Accent’s tolerance and resistance to high temperature and drought stress were stronger than those of Fairway and Bartwingo, but were not significant.