【作者】 余静；

【导师】 陈少风；

【作者基本信息】 南昌大学 ， 生态学， 2014， 硕士

【摘要】 鄱阳湖湿地常年处于旱涝交替的状态中，湿地优势植物在适应鄱阳湖湿地环境的过程中，营养器官的解剖形态既具有抗旱性特征又有耐涝性特征。本文采用常规石蜡切片技术对鄱阳湖湿地沿水位高程梯度分布的16种优势植物的根、茎、叶形态解剖结构进行比较研究。并模拟水分胁迫实验来探索部分优势种的耐涝能力。得出如下主要结果：1.优势植物叶、茎、根的保护组织和机械组织呈现不同程度的加强，表现出较强的抗旱能力。2.输导组织较为发达。不同分布高程的优势植物，因环境中的水分条件不同，使输导组织的发达程度存在较大差异。禾本科和莎草科植物的维管束束数最多。部分优势植物茎内的维管束束数与分布高程呈显著负相关，与土壤含水量呈显著正相关；而导管数、气腔数与分布高程呈显著正相关。3.所有优势种的营养器官内都有气腔形成，组成了由上至下贯穿植物体的空气通道，保证气体在植物体内的运输。叶内通气组织来源于叶肉细胞和叶主脉中的气腔；茎内通气组织更为发达，来源于髓腔、薄壁组织和维管束中的气腔；根内通气组织来源于中皮层内薄壁细胞间的气腔。且茎和根的气腔比例与土壤含水量呈显著正相关。4.优势种叶、茎、根的各项形态指标变异系数较大，与分布高程、土壤含水量以及科属间的差异有一定关联。但各指标之间又存在一定的相关性，说明这些植物在适应鄱阳湖湿地环境的过程中，营养器官的解剖形态具有较为明显的协同变化。5.水淹实验中，除蓼子草经水淹后全部淹死外，其他材料叶、茎、根中的气腔比例均随着水淹胁迫时长的增加而出现了不同程度的增长，与水淹时长呈显著正相关；叶、茎、根中厚角组织等机械组织的厚度随着水淹时长的增加而呈现减小的趋势；禾本科和部分莎草科植物的输导组织经水淹后更加发达。由此可见，鄱阳湖湿地优势植物在应对水分胁迫时，其形态解剖结构能够在保护组织、机械组织、输导组织以及通气组织等多方面适应水淹逆境。更多还原

【Abstract】 The Poyang Lake wetland is perennially in the state of droughts and floods.When adapting to this environment, the morphological and anatomical character oftheir vegetative organs can not only adjust to drought conditions but also survive inwaterlogged environment. This paper aims to conduct a comparative study on themorphological and anatomical character of roots, stems and leaves of the16dominantplants which spread on high level waterside of Poyang Lake wetland, and explore theadaptability of certain dominant plants to Poyang Lake wetland environment by waterstress experiment. Main results are concluded as follows:1. Productive tissues and mechanical tissues of roots, stems and leaves ofdominant plants in Poyang Lake wetland developed to different degrees. Theyshowed strong drought resistance of the plants.2. Conducting tissues are relatively developed. Because of the differentdistribution of the dominant plants in Poyang Lake wetland and different moistureconditions they are in, there are huge disparities on develpment lecels of conductingtissues. Among all these plants, the number of vascular bundles of Poaceae and someCyperaceae plants are the biggest. Vascular bundles number inside stems of somedominant plants and the distribution of elevation are of negative corelation while thenumber and soil moisture content are of positive corelation. The number of vesselsand air cavities as well as distribution of elevation are both of positive corelation.3. During the process of adapting to the environment of Poyang Lake wetland,aeration tissues formed in leaves, stems and roots of the dominant plants that arecollected for the study, and then developed into an air channel connecting leaves,stems and roots of the plant, going top-down through the plant to make sure airtransported and stored in the plant. Aeration tissues in leaves are consisted of aircavities of mesophyll cells and spongy tissues and tiny air cavities in the vascularbundles. Aeration tissues in stems are more developed. They are consisted ofmedullary cavities, air cavities that scattered in parenchymatous tissues and aircavities in vascular bundles. Aeration tissues in roots are mainly consisted of air cavities beneath parenchymal cells in mesothelium. It is revealed by the study thatproportion of air cavities in stems and roots of dominant plants is closely related tothe moisture content of the soil where they distribute.4. Coefficient of variation of their leaves, stems and roots is relatively large.Main reason of that is the distribution elevation, water content of the ground anddifferences between species. However, the indexes are related, which meansmorphological and anatomical character of each vegetative organ of the plantobviously coevolved during the process of adapting to the special environment ofPoyang Lake wetland.5. Except for Polygonum criopolitanum, which are drowned in the experiment,with the increasing time of waterlogging, length, number, diameter of air cavity anddiameter of medullary cavity in stems of other dominant plants change to varyingdegrees. The overall scale of air cavities tends to increase with the increasing time ofwaterlogging. They are of positive correlation. The thickness of some mechanicaltissues, including collenchyma tissues in leaves, stems and roots decrease with theincreasing time of waterlogging. In responding to that, the conducting tissues of someCyperaceae and Poaceae plants, become more developed in order to transport morewater inside the plant. Thus it can be seen that by adjusting protective, mechanical,conducting, and aeration tissues, morphological and anatomical structure of thedominant plants in Poyang Lake wetland can help them fully adaptable to thewaterlogged condition.更多还原