干旱胁迫下不同杜鹃品种生理与光合响应

Responses of Physiology and Photosynthesis to Different Rhododendron Cultivars Under Drought Stress

以"胭脂蜜""鸳鸯锦""花蝴蝶""紫宸殿""锦袍""紫鹤"6个杜鹃品种为试材,研究了干旱胁迫下不同杜鹃品种的生理与光合响应。结果表明:随着干旱胁迫时间的延长,所有杜鹃品种叶片出现不同程度的下垂、萎蔫甚至死亡的现象,其中"锦袍"的伤害程度相对最轻。丙二醛(MDA)含量呈持续上升或先升后降的趋势;可溶性蛋白质含量变化较平缓,总体呈下降的趋势,其中"紫鹤"在干旱第10天时含量达到最高;叶绿素含量呈先下降后上升的趋势;初始荧光(Fo)总体呈现下降再平缓上升的状态,其中"花蝴蝶"与"紫鹤"在10d后急剧下降至无,这与外观形态表现一致;最大光化学效率(Fv/Fm)与PSII潜在活性(Fv/Fo)变化规律一致,除2个干旱敏感品种急剧降低以外,其它品种均保持平稳状态。

The responses of physiology and photosynthesis were researched in Rhododendron ‘Yanzhimi＇‘Yuanyangjin＇‘Huahudie＇‘Zichendian＇‘Jinpao＇‘Zihe＇under drought stress.The results showed that the leaves of Rhododendrons became drop,wilting with different degrees and even died,among those,the leaves of‘Jinpao＇were hurt most lightly.The content of MDA increased and then decreased.The content of protein of most Rhododendrons appeared a gently decreasing trend but‘Zihe＇decreased firstly and then increased,reaching the highest point after 10 days.The content of chlorophyll deceased firstly and then increased.Initial fluorescence（Fo）indicated decreasing trend firstly,and then increasing,however,that of‘Huanhudie＇and‘Zihe＇decreased sharply to zero and which was consisted with their appearance.The value of Fv/Fm（Optimal photochemical efficiency of PSII）and Fv/Fo（Potential activity of PSII）remained at a certain state,except two droughtsensitivity cultivars（‘Huanhudie＇‘Zihe＇）decreased sharply.