新疆几种特色果树叶绿素荧光对沙尘胁迫的响应

Sand-dust weather in South Xinjiang and its influence on plant chlorophyll fluorescence as a starting point, Xinjiang several special fruit trees, i.e. Armeniaca vulgaris Lam., Juglans regia L., Zizyphus jujuba Mill., Amygdalus communis L., Cydonia oblonga Mill, Punica granatum L., Malus pumila Mill., Elaeagnus angustifolia L., Ficus carica L., Pyrus sinkiangensis Yu. et al, as the research object, based on analyze leaf morphology and micro structure, chemical composition and particle size of foliar dust, and its damage on the leaf cuticles and influence on the leaf micro meteorological conditions, this project mainly study the pollution resistance of leaves (select 5-6 fruit trees by leaf type), impact of sand-dust cover thickness and its duration on rubisco and rubisco avtivase, photosynthetic pigment contents, proline, soluble protein content, antioxidant enzyme activity and leaf chlorophyll fluorescence, to study the damage and influence of dust stress on leaves and chlorophyll fluorescence in the growing stage of the fruit trees. Research results from the project will provide theoretical proofs for eco-physiological researches which are related to leaf photosynthetic metabolism under sand-dust stress, and it also offer basic data to sand-dust damage reduction management in extreme dry condition.

以南疆多沙尘天气特征及其对植物叶绿素荧光特性的影响为出发点，本课题把新疆（杏、核桃、红枣、巴丹木、榅柏、石榴、苹果、沙枣、无花果、梨等）几种特色果树作为研究对象，在分析果树叶片形态和微结构、叶面沙尘化学成分和粒径分布，沙尘对叶片微气象条件影响的基础上，重点分析几种果树抗污能力（分类选出5-6种果树），分析沙尘覆盖厚度与覆盖时间对果树活动期叶片角质层的伤害，光合色素含量、脯氨酸、可溶性蛋白质含量、Rubisco及Rubisco avtivase活性、叶片组织抗氧化酶活性及叶绿素荧光的影响，进而阐明果树叶绿素荧光对沙尘胁迫的响应。研究结果可为沙尘胁迫下叶片光合代谢相关的生理生态学研究提供理论依据，也可为极端干旱条件下沙尘危害减灾管理提供基础数据。

以南疆多沙尘天气特征及其对植物叶绿素荧光特性的影响为出发点，本课题把新疆（小白杏、石榴、红枣、葡萄、樱桃、核桃、杏、油桃、桃、李子、白桑、无花果、新疆野苹果、秋富、山楂、巴旦木（扁桃）、伊犁香梨、句句梨、库尔勒香梨、西洋梨、阿月浑子等）几十种特色果树作为研究对象，在分析果树叶片形态和微结构、叶面沙尘化学成分和粒径分布，沙尘和遮荫对叶片微气象条件影响的基础上，重点分析几种果树抗污能力，分析沙尘覆盖和遮荫厚度（强度）与覆盖时间对果树活动期叶片角质层的伤害，光合色素含量、脯氨酸、可溶性蛋白质含量、叶片组织抗氧化酶活性及叶绿素荧光的影响，试图阐明果树叶绿素荧光对沙尘胁迫的响应。结果显示：（1）形态结构上，阿月浑子叶片上下表面都有独特的气孔构造，而其它果树的气孔都以凹入或凸出形式分布在叶片下表面；新疆野苹果、开心果、杏、核桃、小白杏、无花果等果树叶片抗污能力最强；叶片在经过沙尘或遮阴胁迫后，叶表面角质层都受到不同程度的伤害，经过沙尘处理的叶片的角质层所受到的伤害要比经过遮阴处理的叶片受到的伤害严重。（2）叶片Pn在短时间沙尘胁迫和遮阴胁迫下均随遮阴率的增加逐渐降低；遮阴率为99%时巴旦木、核桃、苹果和杏叶片Pn在沙尘胁迫下分别比对照叶片Pn降低76%、95%、73%和72%，在遮阴胁迫下分别比对照叶片Pn降低69%、95%、60%和66%。（3）沙尘处理后叶片SOD活性均高于对照组，且随着沙尘覆盖时间的延长逐渐升高，而POD、CAT活性呈先升后降的变化趋势；遮阴胁迫试验中，随着遮阴时间的延长，轻度遮阴处理的果树叶片SOD、CAT活性呈上升趋势，重度遮阴处理的果树叶片中各指标数值先升高后降低；沙尘胁迫试验中，轻度处理的果树叶片脯氨酸、可溶性糖含量的趋势为逐渐上升，而可溶性蛋白含量较对照均增加45.83%后下降趋势。研究结果可为沙尘胁迫下叶片光合代谢相关的生理生态学研究提供理论依据，也可为极端干旱条件下沙尘危害减灾管理提供基础数据。