新疆阜康荒漠红砂种群构件结构与环境因子的灰色关联度分析

 以构件理论为基础,运用灰色关联度分析技术,对新疆阜康荒漠红砂(Reaumuria soongorica)自然种群构件结构及其与环境因子的关系进行了研究。结果表明：1）植株冠幅是表征红砂生长情况的重要指标,随着红砂植株冠幅的增大,植株高度明显增加,而且植株冠幅与植株的一级分枝     

红砂灌丛对土壤和草本植物特征的影响

研究了黄土高原西部荒漠草原区天然红砂灌丛内外土壤水分、养分的差异及植物萌动期红砂灌丛对草本植物生长和植被组成的影响.结果表明:红砂灌丛下土壤水分状况明显好于灌丛外空地,尤其是在30～110 cm土层最为显著;灌丛内土壤粘粒和粉粒含量明显高于灌丛外,而沙粒含量低于灌丛外,尤其是0～10 cm土层;土壤有机质、全效氮、磷、钾及速效氮、磷、钾均在灌丛下富集,富集率分别达到1.40、1.25、1.04、1.05、1.37、1.77和1.49;从灌丛内到灌丛外草本植物的盖度和高度逐渐减小,而植物丰富度增大;红砂灌丛对草本植物密度、盖度和高度的相互作用强度均呈现正值,而植物丰富度的相互作用强度为负值.说明红砂灌丛具有明显的沃岛效应,并对草本植物的生长有促进作用.     

荒漠植物红砂叶片元素含量与气候因子的关系

 通过测定中国境内红砂(Reaumuria soongorica)主要分布区21个自然种群407个植株叶片氮(N)、磷(P)、钾(K)含量、叶片含水量和稳 定碳同位素组成等叶片特征, 分析不同自然种群红砂叶片特征与环境气候因子之间的关系。研究结果表明, 随着年平均最低温度的升高, 红砂 叶片N、P含量、叶片含水量和稳定碳同位素值显著升高。年平均温度和红砂叶片含水量、年平均最高温度和红砂叶片稳定碳同位素值显著正相 关。不同生长区年平均降雨量和平均湿度对红砂叶片特征的影响一致, 与红砂叶片P、K含量和叶片稳定碳同位素值显著负相关, 与叶片N含量和 叶片含水量显著正相关。不同生长区平均日照时数和蒸发量对红砂叶片特征的影响一致, 与红砂叶片P、K含量和叶片稳定碳同位素值显著正相 关, 与叶片含水量显著负相关。说明不同自然种群中红砂叶片特征受气候条件的影响显著, 不同气候因子对红砂叶片特征的贡献显著不同。不 同种群间红砂叶片N含量的变化是各气象因子均衡作用的结果, 年平均湿度是影响红砂叶片K含量和稳定碳同位素值的主要限制因子, 蒸发量是 影响红砂叶片P含量的关键因子, 平均日照时数是影响红砂叶片含水量的关键因子。红砂叶片特征对不同环境条件下气候因子的这种响应模式在 一定程度上反映和指示了以红砂为建群种荒漠生态系统的环境状况和稳定程度。     

新疆阜康荒漠红砂种群遗传结构及其与生态因子的耦合关系

Genetic structure and differentiation of Reaumuria soongorica (Pall.) Maxim population from the desert of Fukang, Xinjiang, were assessed by means of random amplified polymorphic DNA (RAPD) markers. High genetic diversity and differentiation were revealed in the population of R. soongorica by 15 random primers. One hundred and thirty-six individuals from seven subpopulations were sampled in the study. Seventy-one loci have been detected, and among them 69 were polymorphic. The mean proportion of polymorphic loci (PPB) was 97.18%. The analyses of Shannon information index (0.307 5), Nei抯 gene diversity (0.312 7) and GST (0.312 0) indicated that there were more genetic variations within the subpopu-lations than those among the subpopulations. The results of AMOVA analysis showed that 61.58% of the genetic variations existed within subpopulations, and 38.02% among the subpopulations. The gene flow among the subpopulations of R. soongorica (Nm = 1.102 8) was much less than that of the common anemophytes (Nm = 5.24), so genetic differentiation among the subpopulations occurred to some extent. Additionally, through the use of clustering and the correlation analyses, we found that the genetic struc-ture of natural population of R. soongorica was related to some ecological factors (soil factors mainly) of the oasis-desert transition zone. The genetic diversity level of R. soongorica had negative correlation with the content of total soil P and Cl- significantly (P＜0.05). On the contrary, it had significant positive correlation with CO32- (P＜0.05), showing that the distribution of the individuals of R. soongorica in the sampled areas correlates with certain soluble salt. Furthermore, the genetic diversity of the natural population of R. soongorica increased with the decreasing of the content of soil organic matters, water, total N and total P in soil. The paper concluded that the microenvironment ecological factors played an important role in the adaptive evolution of R. soongorica population.     

红砂3个地理种群的光合特性及其影响因素

在自然条件下对分布于兰州九州台(LZJ)、张掖临泽(ZYL)和武威民勤(WWM)3个地理种群的红砂(Reaumuria soongorica)的光合特性进行了研究,并对其影响因素进行了分析。结果表明,红砂3个地理种群叶片的光合速率和蒸腾速率日变化规律相似,均为双峰型,光合有明显的\"午休\"现象。影响红砂光合的因素既有环境因子又有自身因素。在环境因子中,无论是对光合速率还是蒸腾速率,光照强度都是最重要的主导因子,其次是气温,大气湿度则与植物的蒸腾速率成负相关。各因素的影响程度因不同地理种群所处土壤含水量不同而有所不同。内在因素中气孔导度下降是光合速率下降的主要原因,外界因素又通过气孔调节来影响蒸腾速率。光抑制是影响红砂光合午休的非气孔因素之一,且干旱加重了光抑制。在干旱胁迫下,叶绿素含量也是影响光合速率的主要原因。所有这些因素协同作用于红砂的光合作用,处于极端干旱环境中的红砂则通过降低蒸腾,提高水分利用率和稳定性碳同位素等途径来响应环境胁迫,从而提高对环境的适应性。     

荒漠植物红砂抗旱性与其电学参数关系的研究

为了研究电学参数与红砂(Reaumuria soongorica)抗旱性的关系,以4个地理种源的荒漠植物红砂2年生苗木为材料,测定其茎在不同干旱胁迫处理下的高频电阻(r)、低频电阻(rl)、胞外电阻率(re)、胞内电阻率(ri)、电导(G)和电纳(B)等电学参数以及膜透性(RPP)和渗透调节物质脯氨酸(Pro)含量的变化,分析电学参数与膜透性和脯氨酸含量间的相关性。结果显示,随着干旱胁迫的加剧,4个地理种源红砂茎的膜透性和脯氨酸含量均呈逐渐升高或先升高后降低趋势,不同种源间存在显著差异(P0.05)。红砂茎膜透性的大小在4个种源间表现为:兰州张掖酒泉武威,脯氨酸含量由高到低依次为武威酒泉张掖兰州。4个地理种源红砂茎的高频电阻呈逐渐下降趋势,胞外电阻率、胞内电阻率、电导呈先升高后降低的趋势,而低频电阻则与它们相反,电纳的变化则较为复杂。6个电阻参数在不同种源材料间和不同处理间差异均显著(P0.05)。相关性和通径分析结果表明,胞外电阻率、胞内电阻率、高频电阻和电纳与膜透性的相关性较为明显;胞外电阻率、胞内电阻率、高频电阻和电导与脯氨酸含量的相关性较为显著,其中胞内电阻率对膜透性和脯氨酸含量的影响最大,通径系数绝对值分别高达0.938和0.897。说明电学参数ri可以作为表征红砂抗旱特性的参数,也表明电学方法将是荒漠植物逆境胁迫研究的一种有效方法。     

新疆阜康荒漠红砂种群遗传结构及其与生态因子的耦合关系

应用RAPD标记技术对分布于新疆阜康荒漠的重要植物红砂(Reaumuria soongorica(Pall.)Maxim)种群遗传结构和遗传多样性进行了分析。15条随机引物对红砂7个亚种群的136个个体进行扩增,共检测71个位点,其中多态位点69个。研究结果表明:红砂种群的多态位点比率(PPB)为97.18％,显示出分布于过渡带的红砂种群内存在较高的遗传多样性。Shannon多样性指数(0.307 5)、Nei基因多样性指数(0.312 7)和基因分化系数(G_(ST)=0.312 0)揭示了红砂种群遗传变异多存在于亚种群内,而亚种群间的遗传分化则较小。红砂业种群间的基因流Nm=1.102 8,Nm>1但低于一般风媒传粉植物(Nm=5.24)的基因流水平,处于分化的临界状态。AMOVA分析说明红砂种群变异的61.58％存在于亚种群内,而亚种群间的变异占总变异的38.02％。另外,通过RAPD资料的聚类分析及相关性分析研究,发现红砂自然种群的遗传结构与绿洲荒漠过渡带的微生境生态因子(主要是土壤因子)相关,其中红砂亚种群遗传多样性水平与土壤中全磷和CI含量呈显著负相关,与CO_3~2含量呈显著正相关。而其它土壤生态因子则与红砂的遗传多样性指数的相关性均不显著(P>0.05)。表明红砂个体的分布可能与过渡带土壤的某些易溶性盐分相关。研究还发现,随着土壤中有机质、水分、全氮和全磷含量的减     

Correlations Between Foliar Stable Carbon Isotope Composition and Environ-mental Factors in Desert Plant Reaumuria soongorica (Pall.) Maxim.

Leaves of 407 individuals of Reaumuria soongorica (Pall.) Maxim. collected from the major distribution areas were measured to investigate the distribution characteristics of the stable carbon isotope in this desert plant, as well as correlations between δ13C values and environmental factors. Results showed that δ13C values in R. soongorica ranged from-22.77‰. to-29.85‰. and that the mean δ13C value (-26.52‰)was higher than a previously reported δ13C value for a different desert ecosystem. This indicates that R.soongorica belongs to the C3 photosynthetic pathway and has higher water use efficiency than other species. The correlations between δ13C values and environmental factors demonstrated that the foliar δ13C values in R. soongorica increased significantly with decreasing mean annual precipitation and mean relative humidity, and decreased with decreasing duration of sunshine and evaporation. The spatial distribution trend of δ13C values in R. soongorica was not obvious and there was no significant correlation between the δ13C values and mean annual temperature. We conclude that different distribution trends in δ13C values for R. soongorica were likely caused by stomatal limitation rather than by nutrient-related changes in photosynthetic efficiency and that precipitation played an important role in the wide distribution range of R.soongorica. This pattern of δ13C values for R. soongorica reinforced that it is a super-xerophil in terms of its adaptive strategies to a desert environment.     

盐分生境下长叶红砂和红砂内源激素含量及其生境差异性

运用酶联免疫吸附法比较分析了盐分生境下长叶红砂及其近缘种红砂叶片中4种内源激素的含量差异,并对其在不同生境间的差异性进行了研究.结果表明:同一生境下长叶红砂的促进生长型激素吲哚乙酸(IAA)、赤霉素(GA3)和玉米素核苷(ZR)含量均低于红砂,抑制性激素脱落酸(ABA)含量高于红砂,这可能是长叶红砂的生态适应性弱于红砂的重要内在原因之一.长叶红砂的内源激素在不同生境间存在差异,(IAA+ZR+GA3)/ABA表现为:盐渍土>非盐渍土>重盐土,这与盐渍土的长叶红砂种群密度和盖度最大、非盐渍土次之、重盐土最小的结果一致,反映出长期生长在盐生环境下的长叶红砂已经进化出相应的内在适应机制,盐胁迫下内源激素的综合调控对长叶红砂的生长发育起到至关重要的作用.     

红砂不同株型在干旱盐碱胁迫下脯氨酸、丙二醛及抗氧化酶含量的研究

以阿拉善左旗红砂(Reaumuria soongorica)群落为研究对象,通过氧化酶（POD、SOD、CAT）活性、丙二醛（MDA）、脯氨酸（Pro）含量、地上部分含水率测定及模糊数学函数分析,探讨了不同株型红砂在干旱盐碱环境下的生理适应能力,得出如下结果：红砂地上部分株型越大含水率越大;不同株型的红砂植株在不同株型间MDA、SOD、POD、Pro的含量均无显著差异;红砂适应性综合评价结果均属于中抗型,具体为中株>大株>小株。