不同地理种源野生黑果枸杞对风沙流胁迫的耐性及适应机制

Wind-sand flow is an important factor for growing and regenerating of plants in wind-sand damage area.The study of relationship bewteen plant growth and wind-sand blow is a ecological issue related to evolution. The sand grain abrase and strike on plants surface can induce direct physical stress and damage. Plants which growing in wind-sand flow environment for a long term can form a special mechanism to slow down and prevent the damage of wind-sand flow. This study object of this project is wild Lycium ruthenicum of different geographical populations, the experiment will be conducted by simulate wind-sand flow in wind tunnel, the response process and mechanism of phenotypic characteristics, leaf anatomical structure, chlorophyll fluorescence, osmotic adjustment substances, and membrane permeability will be studied under conditions of differ sand transport rate, differ blow time and differ interval time. Based on the experiment data, we can discuss the relationship bewteen components allocation model, spatial geometry configuration and wind-sand flow stress; establish quantitative relationship between plant damage extent and differ features of wind-sand flow; Clarify the response process of physiological ecology parameters and its generalized mechanisms; Ascertain the tolerate threshold value and repair capacity of differ geographical populations. The study results have an important scientific significance to reveal the damage process, endurance capacity, and existing mechanism of wild Lycium ruthenicum under stress of wind-sand flow environment, at the same time, provide the scientific basis for comprehensive evaluation of stress resistance of Lycium ruthenicum germplasm resources.

风沙流是影响风沙危害区植物生长发育及更新的重要环境因子，植物生长发育与风沙流关系的研究是与植物逆境适应有关的生态学问题。风沙流对植物体表面的磨蚀和击打可引起直接的物理胁迫和损伤，长期生活在风沙流环境中的植物会形成减缓和防止风沙流危害的特殊机制。本项目以荒漠区不同地理种源的野生黑果枸杞为研究对象，采用风洞模拟风沙流吹袭胁迫试验，研究不同风沙流强度、不同持续时间及不同间隔时间下黑果枸杞表型特征、叶片解剖结构、叶绿素荧光、渗透调节物质及膜透性的响应过程和机制；探讨构件分配模式及空间构型与风沙流胁迫的关系；建立植株受损程度与不同风沙流条件间的量化关系；阐明黑果枸杞对风沙流胁迫的生理生态响应过程和一般性机理，确定不同地理种源黑果枸杞对风沙流胁迫的耐受阈值和修复能力。研究结果对揭示风沙环境中黑果枸杞的受损过程、耐受能力和生存机制具有重要的科学意义，同时为黑果枸杞种质资源的抗逆性综合评价提供科学依据。

风沙流危害是我国北方和西部风沙区的主要自然灾害，长期生活在风、风沙流环境中的植物会形成减缓和防止风沙流危害的特殊机制。本项目以民勤、金塔、永靖种源的黑果枸杞为研究对象，采用风洞模拟风沙流吹袭胁迫试验，研究风沙流不同强度、不同持续时间以及不同间隔时间下黑果枸杞对风沙流胁迫的耐性及生理生态调控机制。结果表明：（1）表型结构。在风/风沙流胁迫下，黑果枸杞植株向背风侧弯曲，侧枝与主茎夹角减小，冠部呈不对称的“旗型”，胁迫结束后的2～4h内黑果枸杞空间构型逐渐恢复原状。风沙流胁迫频繁的民勤和金塔两地的黑果枸杞生长受限，株高和侧枝长均较短，植株构型更加紧凑。（2）叶片解剖结构。黑果枸杞叶片厚度和角质层较厚，表皮细胞内有贮水组织，栅栏组织发达且为环栅型，海绵组织相对退化。风沙频次高的民勤、金塔2地的黑果枸杞叶片主要通过降低叶片大小及厚度来适应外界环境条件。（3）光合系统。气孔因素和非气孔因素共同影响黑果枸杞叶片气孔的开闭，进而影响黑果枸杞的光合作用。不同强度风沙流胁迫下，非气孔因素起到调节作用较大；不同时间胁迫下，气孔因素则起了明显的调节作用。（4）抗逆生理。风沙流处理下膜透性均呈增大趋势，风速增大对黑果枸杞造成膜脂过氧化作用较小，胁迫时间延长则引起明显的膜脂过氧化作用。SOD活性对胁迫较敏感，POD活性和CAT活性对胁迫较迟钝，且短时间胁迫酶活性较高，保护作用较强。（5）民勤、金塔种源主要通过POD活性、RWC、WSD、FW、BW和BW/FW变化响应风沙流胁迫，永靖种源主要通过膜透性、FW、BW、BW/FW和Fv'/Fm' 变化响应风沙流胁迫。黑果枸杞抗风沙能力排名为民勤种源＞金塔种源＞永靖种源。研究结果对揭示风沙环境中黑果枸杞的受损过程、耐受能力和生存机制具有重要的科学意义，同时为黑果枸杞种质资源的抗逆性综合评价和优良种质筛选提供科学依据。