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题名	水、盐胁迫下两种盐生植物生物量分配对策的研究
作者	贺海波
学位类别	硕士
答辩日期	2007
授予单位	中国科学院．新疆生态与地理研究所
导师	李彦，新疆生态与地理研究所
关键词	一年生草本
其他题名	Biomass allocation in two desert halophyte plants: A study along water and salt stress gradients
中文摘要	盐生植物是生长在盐渍环境中的一类天然植物区系。该类植物生长的环境，由于具有蒸发/降水比大、土壤严重盐渍化的显著特点，导致可利用水资源匮乏，表层土壤盐分大量富集。一般认为，生活在逆境中的植物，具有生物量分配模式可塑性的适应对策，且植物生物量分配模式自我调节的变化趋势，往往符合最优分配理论的预测。但近年来，随着研究不断深入，研究者通过试验及理论分析发现：植物自身生长过程中存在的个体发育漂变，也会显著影响植物不同器官间生物量的分割，造成植物生物量分配的无源可塑性。近年来，国内外学者对植物生物量分配的分配对策及其调节模式开展了大量的研究，但是对广泛分布于盐漠中的盐生植物研究相对较少。本文以2种一年生盐生草本植物钠猪毛菜、盐生草为试验对象，在营养生长期为盆栽沙培植株设置1个空白处理、2个梯度，采用连续溢出法在营养生长期间隔不同时间连续取样，研究干旱和盐分胁迫条件下两种盐生植物生物量分配对策。实验地点设置在中国科学院新疆阜康生态站。试验共设5个处理水平——空白对照组 (BT)、轻度干旱胁迫（W1T）、重度干旱胁迫（W2T）、轻度盐分胁迫(S1T) ，重度盐分胁迫（S2T）。除试验设置的水分含量和盐分浓度的差异外，保持各处理的其它条件与空白对照处理相一致。盆栽植株按处理组，分组摆放在遮荫网下。在植物营养生长过程中，采用连续溢出法，测量不同时期、不同处理组的盐生植株的总生物量(BM)、地上部分生物量（SB）、根冠比（R/S，根重/地上部分重）、叶面积比（LAR，总叶面积/总生物量重）。试验结果表明不同程度干旱和盐分胁迫显著影响了2种盐生植物的生长、生物量积累和生物量的分割。生长分析表明：2种盐生植物在生长率、根冠比、叶面积比方面，皆存在明显可塑性，且根冠比、叶面积比的变化均受到个体发育漂变的影响：在整个营养生长期的不同处理组中，根冠比、叶面积比总体上均呈逐渐降低趋势。不同干旱胁迫处理下2种盐生植物的根冠比和叶面积比的变化与最优理论和模型的预测相一致：随干旱胁迫的加重，根冠比增大而叶面积比减小。但在盐分胁迫条件下，2种盐生植物并未出现基于最优分配理论来调节生物量分配模式，且2种盐生植物根冠比和叶面积比的响应表现出明显的种间差异。此外，不同处理组间植物生物量分配特征（根冠比、叶面积比）的差异，往往只存在于生活史的某一时期，在整个营养生长期间，并不自始至终保持一致。How plants respond to variation in the availability of resources in their environment is a central question in plant ecology. Optimal partitioning models and theories suggest that plants respond to variation in the environment by partitioning biomass among various plant organs to optimize the capture of nutrients, light, water, and carbon dioxide in a manner that maximizes plant growth rate. For example, plants exposed to reduced sunlight would be predicted to shift resources toward stem and leaf growth. The theory surrounding optimal partitioning is generally accepted and a number of studies report adjustments in biomass allocation consistent with it .But, recently, some scientists suggested that adjustments in biomass allocation as a consequence of normal plant growth and development may be responsible for some or all of the adjustments in biomass allocation cited in support of optimal partitioning theories. To determine whether observed patterns of allocational plasticity of halophyte are consistent with optimal partitioning theory. The Individuals of the annual desert halophyte plants species Salsola nitraria and Halogeton glomeratus were pot grown from the naturally habitat-gathered seed in controlled conditions across two separate gradients of drought and salt stress. Frequent harvests were used to determine the growth and allocation (root vs. shoot, and leaf area vs. biomass) response of these plants over 70-d period in order to understand the effect of soil drought and salt stress on growth and biomass allocation of these plants, to find out whether these plants respond to variation in the environment by adjusting biomass allocation among various plant organs, and to determine whether observed patterns of allocational plasticity are consistent with optimal partitioning theory. Growth analysis revealed that each species displayed significant plasticity in growth rates and substantial amounts of ontogenetic drift in root: shoot biomass ratios and ratios of leaf area to biomass across each of the three resource gradients. Ontogenetically controlled comparisons of root: shoot and leaf area ratios across drought stress gradients were generally consistent with predictions based on optimal partitioning theory; allocation to roots increased and leaf area decreased under heavy drought stress. But these annual desert halophyte species did not alter biomass allocation in response to the broadly varying salt stress. Furthermore, many of the observed differences in biomass allocation were limited to a given time during growth and development.
语种	中文
学科主题	植物生理学
公开日期	2010-11-12
页码	共55页
内容类型	学位论文
源URL	[http://ir.xjlas.org/handle/365004/7968]
专题	新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据)
推荐引用方式 GB/T 7714	贺海波. 水、盐胁迫下两种盐生植物生物量分配对策的研究[D]. 中国科学院．新疆生态与地理研究所. 2007.

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