高温胁迫对三种杜鹃生长及生理的影响

Effects of High Temperature Stress on the Growth and Physiology of Three Rhododendron Species

以鹿角杜鹃、溪畔杜鹃及羊踯躅3种杜鹃为试材,利用人工气候培养箱模拟高温胁迫,研究不同高温胁迫(昼14 h/夜10 h,对照25℃/21℃,轻度胁迫32℃/25℃,中度胁迫38℃/28℃,重度胁迫42℃/31℃)对3种杜鹃的株高、地径、叶片相对含水量、生物量、根冠比、叶绿素含量、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、可溶性蛋白质含量及可溶性糖含量的影响,以期筛选出抗热能力更强的杜鹃品种。结果表明:随着高温胁迫程度的加强,3种杜鹃生长指标中的株高增量、地径增量、叶片相对含水量及总生物量均显著减少,根冠比呈现先升高后降低的趋势;3种杜鹃叶片的SOD活性呈现逐渐增加或先增加后降低的趋势,MDA含量均呈现逐渐增加的趋势,叶片叶绿素a、叶绿素b含量均呈现出逐渐降低的趋势,可溶性蛋白质及可溶性糖含量均呈现出逐渐增加或先增加后降低的趋势,与对照相比,整体为增加趋势。

Taking Rhododendron latoucheae,R.rivulare and R.molle as experimental materials,and an artificial climate incubator to simulate high temperature stress was used,the effects of different high temperature stress(14 hours day/10 hours night,control 25 ℃/21 ℃,mild stress 32 ℃/25 ℃,moderate stress 38 ℃/28 ℃,severe stress 42 ℃/31 ℃) on plant height,ground diameter,leaf relative water content,biomass,root shoot ratio,chlorophyll content,SOD activity,malondialdehyde content,soluble protein content and soluble sugar content of three species of Rhododendron were studied,in order to identify Rhododendron varieties with stronger heat resistance.The results showed that with the degree of high temperature stress increased,the plant height increment,ground diameter increment,leaf relative water content,and total biomass in the growth indicators of the three Rhododendrons showed a significant decrease,and the root shoot ratio showed a trend of first increasing and then decreasing;SOD activity of the leaves of the three Rhododendrons showed a trend of gradual increase or first increase and then decrease,MDA content of the leaves of the three Rhododendrons showed a trend of gradual increase,chlorophyll a and chlorophyll b content of the leaves of the three Rhododendrons showed a trend of gradual decrease,soluble protein and soluble sugar content of the three Rhododendrons showed a trend of gradual increase or first increase and then decrease,compared with the control,there was an increasing trend overall.