蛇莓相连分株对异质盐胁迫的表型响应及褪黑素介导调控

发布时间：2018-04-28 14:08

本文选题：克隆植物 + 蛇莓　；参考：《中国林业科学研究院》2017年硕士论文

【摘要】：盐胁迫是自然界最严重的非生物胁迫因子之一。滨海盐碱地分布广、生境恶劣,且随着不科学地过度开发,滨海盐碱地面积不断扩大,土地生产力持续下降,盐碱地盐分分布特征及植物材料是影响滨海盐碱地植被覆盖质量的重要因素。滨海盐碱地盐分受坡度、光照、水分等自然因素影响,呈现不均匀的分布格局。克隆植物通过匍匐茎、根状茎等结构在其节上形成生理上相互连接而形态上相对独立的分株,使得分株间存在广泛的资源、能量和信号的交流与共享,即生理整合。因此,克隆植物是实现资源异质化分布立地环境的植被均匀覆盖的理想材料。蛇莓是一种典型的匍匐茎型克隆植物,抗性较强、养护成本低,被广泛应用于林下、石质边坡等裸露地植被覆盖。研究克隆植物蛇莓对异质性盐胁迫的响应及适应性机制,对挖掘蛇莓的应用潜力具有重要意义。褪黑素是极强的抗氧化剂,在调节植物生长、提高植物抗逆性方面发挥显著作用。基于此,本研究初步分析了异质盐胁迫下蛇莓克隆相连分株表型及生理可塑性响应,以及外源褪黑素介导提高克隆植物抗性的生理机制,从全新角度明确克隆植物抗盐性形成及其调控机制,为科学评价克隆植物耐盐性以及筛选高抗克隆植物材料提供参考,并为滨海盐碱地植被覆盖与城市园林建设提供新思路。本研究采用盆栽法,以克隆植物蛇莓(Duchesnea indica(Andr.)Focke)为材料,研究了其耐盐机理以及褪黑素(Melatonin)对其耐盐性的调控功能。主要研究结果如下:(1)盐胁迫抑制克隆植物蛇莓生长,并影响其生理代谢。盐胁迫下,随着盐害加剧蛇莓的叶片受害率及叶片枯亡率上升,植株物质积累能力下降,叶绿素合成受抑制,叶片加速失水,并且造成细胞膜系统受伤害,导致细胞膜透性的丧失、膜脂过氧化反应加强并且积累大量的过氧化氢。(2)蛇莓相连分株间存在生理整合,对异质性盐胁迫的具有很强的适应能力。盐胁迫下,受胁迫分株可以与未受胁迫分株共享水分及养分资源,共同响应受害信号,以减少受胁迫分株的受害程度,延长植株整体的生存时间,增强植株的耐盐性。(3)外源褪黑素显著影响克隆植株蛇莓异质性盐胁迫下的表型及生理响应。外褪黑素能保护蛇莓在盐胁迫下的物质积累能力、抑制叶绿素的降解、减少水分的丧失并保护细胞膜系统、增强清除过氧化物的能力,从而缓解盐胁迫蛇莓植株造成的伤害。其中浓度为200μmol/L的褪黑素调控效果相对最为显著。
[Abstract]:Salt stress is one of the most serious abiotic stress factors in nature. Along with unscientific over-exploitation, the area of coastal saline-alkali land is expanding continuously, and the productivity of the land continues to decline. The characteristics of salt distribution and plant materials in saline-alkali soil are the important factors that affect the vegetation coverage quality in coastal saline-alkali land. The salinity of coastal saline-alkali land is influenced by natural factors such as slope, illumination and moisture, and presents an uneven distribution pattern. Clonal plants form ramet plants which are physiologically connected and relatively independent in morphology through stolon rhizome and other structures which result in extensive communication and sharing of energy and signal among ramet plants namely physiological integration. Therefore, cloning plants is an ideal material for uniform vegetation coverage in heterogeneous sites. Raspberry is a typical stoloniferous clonal plant with strong resistance and low maintenance cost. It has been widely used in undergrowth, rock slope and other bare land vegetation cover. It is of great significance to study the response and adaptive mechanism of cloned plant Snake berry to heterogeneous salt stress and to exploit its application potential. Melatonin is a powerful antioxidant and plays a significant role in regulating plant growth and improving plant resistance to stress. Based on this, this study preliminarily analyzed the phenotypic and physiological plasticity response of clone ramet of Raspberry under heterogeneous salt stress, and the physiological mechanism of exogenous melatonin mediated enhancement of clonal plant resistance. The formation and regulation mechanism of salt-resistance of cloned plants are clarified from a new perspective, which provides a reference for the scientific evaluation of salt tolerance of cloned plants and the screening of high-resistant clone plant materials, and provides a new idea for vegetation cover and urban garden construction in coastal saline-alkali land. In this study, the salt-tolerance mechanism of Duchesnea indica Andr.Focke, a cloned plant, and the regulation of melatonin on its salt tolerance were studied by pot culture. The main results were as follows: 1) Salt stress inhibited the growth and physiological metabolism of the cloned plant. Under salt stress, the leaf damage rate and leaf death rate increased with the increase of salt injury, the accumulation ability of plant material decreased, chlorophyll synthesis was inhibited, leaf accelerated water loss, and the cell membrane system was damaged. The loss of cell membrane permeability, the enhancement of membrane lipid peroxidation and the accumulation of a large amount of hydrogen peroxide. Under salt stress, ramets under stress can share water and nutrient resources with ramet plants without stress, so as to reduce the degree of injury and prolong the whole survival time of ramet plants. The exogenous melatonin significantly affected the phenotypic and physiological responses of the cloned plants under heterogeneous salt stress. Exogenous melatonin can protect the ability of substance accumulation, inhibit the degradation of chlorophyll, reduce the loss of water and protect the cell membrane system, enhance the ability of scavenging peroxide, so as to alleviate the damage caused by salt stress. The effect of melatonin at the concentration of 200 渭 mol/L was the most significant.
【学位授予单位】：中国林业科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S688.4

【参考文献】