This paper reports a study of the effects of different treatments (spring mowing, spring firing, autumn mowing, and a contrast test) on the growth and physiological characteristics of Alhagi sparsifolia in the southern fringe of the Taklimakan Desert. The results show that under autumn mowing the leaves were significantly thicker and had a higher ratio of leaf length to width, indicating increased capability to transfer energy and material compared to the other treatments. All the treatments reduced A. sparsifolia plant growth and regeneration. However, mowing in autumn showed the strongest regenerative capability of the three treatments. Autumn mowing produced leaves with significantly higher photosynthetic pigment content than the other treatments. All three treatments reduced the physiological damage to A. sparsifolia from the external environment, though mowing in autumn showed the strongest resistance. The paper thus concludes that autumn moving is the best management practice for A. sparsifolia .

本实验以塔克拉玛干沙漠南缘疏叶骆驼刺为研究对象,设置春季刈割、春季火烧、秋季刈割、对照4个处理,研究干扰对其生长及生理特征的影响。研究结果表明,1)秋季刈割叶片长宽比、叶片厚度显著大于其他处理,叶片进行能量交换、物质积累的能力最强。2)不同干扰方式均降低了疏叶骆驼刺株高,不利于疏叶骆驼刺的恢复与再生,3种人为干扰方式比较秋季刈割骆驼刺再生能力最强。3)秋季刈割叶片叶绿素含量显著高于其他处理。4)3种干扰在生理上降低了疏叶骆驼刺受外界逆境的损害,秋季刈割抗逆性最强。因此,秋季适度刈割是疏叶骆驼刺最佳的保护性利用措施。

Aims The responses of plant roots to soil heterogeneity and the interactive effects among plant roots have been important research topics in recent years. Most studies have focused on annual plant species and conducted experiments in controlled greenhouse conditions. Few comprehensive studies have been carried out on the response of perennial plant roots to soil heterogeneity and competition. Our objective is to investigate the responses and adaptive strategies of root-system growth of the perennial plant Alhagi sparsifolia to nutrient heterogeneity and competition. Methods We used sheep feces as nutrient patches to form soil heterogeneity and planted A. sparsifolia in glass pools. Seedlings received one of six factorial combinations of soil heterogeneity (uniform, patch-center and patch-edge) and competition treatments (alone versus with competition). We excavated whole plants and analyzed their root biomass, root respiration, root system architecture and other related characteristics in each treatment after 100 days. Important findings Roots of A. sparsifolia grow in the direction where soil space is abundant under no plant competition, even though nutrient patches are present on the opposite side. Roots of A. sparsifolia also grow in the direction where soil space is abundant under plant competition, but neighboring plants limited the development of focal plants, resulting in significantly reduced root and shoot biomass ( p A. sparsifolia roots needs both nutrients and soil space, and space is more important than nutrients. If neighbors are present, plant roots first occupy the space where competitors exist.

近年来, 植物根系对土壤异质性的响应和植物根系之间的相互作用一直是研究的热点。过去的研究主要是针对一年生短命植物进行的, 而且多是在人工控制的温室条件下进行的。而对于多年生植物根系对养分异质性和竞争的综合作用研究很少。该文对塔里木盆地南缘多年生植物疏叶骆驼刺( Alhagi sparsifolia )根系生长对养分异质性和竞争条件的响应途径与适应策略进行了研究, 结果表明: (1)在无竞争的条件下, 疏叶骆驼刺根系优先向空间大的地方生长, 即使另一侧有养分斑块存在, 其根系也向着空间大的一侧生长; (2)在有竞争的条件下, 疏叶骆驼刺根系生长依然是优先占领空间大的一侧, 但是竞争者的存在抑制了疏叶骆驼刺的生长, 导致其枝叶生物量和根系生物量都明显减少( p 株植物的根系都先长向靠近竞争者一侧的空间, 即先占据“共有空间”。研究结果对理解植物根系觅食行为和植物对环境的适应策略有重要意义。

We chose the dominant plant species Alhagi sparsifolia in the south fringe of the Takelamkan Desert as object, measured and analyzed the effects of different irrigation (A, total 360 mm,twice; B, total 180 mm,once; C, total 180 mm,twice; D,total 0 mm) on the characteristics of root growth of seedlings, aboveground part growth of ramets, root architecture of ramets in Qira, Xinjiang, China. The results showed that the root-shoot ratios of A. sparsifolia seedlings were not significantly different among the four treatments, the root growth depth increased with decreasing soil moisture; the number of the abovegound part of ramets all decreased with increasing soil moisture under different treatments; the plant height, aboveground biomass of ramets under different treatments were significantly different except that aboveground biomass between treatment B and treatment C(p

以塔克拉玛干沙漠南缘优势植物种疏叶骆驼刺(Alhagi sparsifolia)为对象，在策勒荒漠草地生态系统国家野外科学观测研究站进行田间试验，对不同水分条件下疏叶骆驼刺幼苗根系生长特征、分株地上部分生长特征、分株根系构型特征进行了研究。结果表明：疏叶骆驼刺幼苗根冠比在不同水分处理之间差异不显著，根系深度随着土壤水分有效性的降低逐渐增加;分株地上部分指标均随土壤水分有效性降低显著减小，除处理B（灌溉量180 mm，灌溉1次）和处理C（灌溉量90 mm，灌溉2次）之间地上生物量差异不显著外，不同处理之间分株株高、冠幅、地上生物量差异均达到显著水平（p

Potamogeton malaianus, P. maackianus, Vallisneria spiralis, Myriophyllum spicatum and Hydrilla verticillata are common dominant submersed macrophytes in lakes of the middle and lower reaches of the Changjiang River. We investigated the regeneration abilities of these five species in growing experiment. The species can be arranged in order of increasing rate of production of asexual propagules: H. verticillata > P. maackianus > P. malaianus > V. spiralis > M. spicatum. Rates of survival of plants were measured at two scales : 1) the whole plant, in which survival of H. verticillata > M. spicatum > P. maackianu > P. malaianus > V. spiralis, and 2) vegetative propagules: H. verticillata > V. spiralis > M. spicatum > P. maackianus P. malaianus. In addition to the fragment of Myriophyllum spicatum, colonization ability (root growth rate) of each species was correlated with its survival rate and the ranks order of colonization ability in the 5 species and their propagules were identical to that of their rates of survival.

竹叶眼子菜(Potamogeton malaianus)、微齿眼子菜(Potamogeton maackianus)、苦草(Vallisneria spiralis)、穗花狐尾藻(Myriophyllum spicatum)、黑藻(Hydrilla verticillata)是长江中下游湖泊主要的沉水植物。在栽培条件下，它们的无性繁殖速率(单位时间内新增个体数)大小顺序为黑藻>微齿眼子菜>竹叶眼子菜>苦草>穗花狐尾藻。同时采用抛掷实验的方法观察研究了这5种沉水植物及其无性繁殖体的存活和生根情况；完整植株存活率为黑藻>穗花狐尾藻>微齿眼子菜>竹叶眼子菜>苦草，无性繁殖体部分存活率为黑藻>苦草>穗花狐尾藻>微齿眼子菜>竹叶眼子菜。生根能力和其存活时间长短相关，而且生根能力与存活率大小基本一致。在实验中，只有穗花狐尾藻的断枝存活率和生根能力存在差异，故无性繁殖体生根能力为黑藻>苦草>微齿眼子菜>竹叶眼子菜>穗花狐尾藻。

As one of the most serious soil erosion areas in China, grassland vegetation is priority for vegetation construction in the Loess Plateau area by its unique geographical conditions and limited water. Grassland vegetation has already contributed a lot to control soil water erosion. Based on the relationships between different parts of grassland vegetation and soil erosion, the present paper drew a conclusion that grassland aboveground parts can weaken rainfall energy and runoff erosion power, and grass roots were able to enhance soil penetrability and soil anti-erodibility by improving soil properties and winding soil mass. In order to provide references for vegetation preventing and controlling soil erosion in Loess Plateau, two aspects of current research progress were summarized including the grassland aboveground part controlling soil erosion power and grass roots enhancing soil anti-erodibility and the exiting problem were discussed.

作为我国水土流失最为严重的地区之一,黄土高原地区独特的地理环境条件和有限的水资源要求该区的林草植被建设以草地植被为主,草地植被在控制土壤水蚀方面已取得了重大进展。本研究根据草地植被地上和地下部分与土壤侵蚀的关系,分析得出,草地植被地上部分能够削弱雨滴击溅动力,减小坡面径流冲刷能力;根系可改善土壤结构,提高土壤入渗能力,增强土壤抗侵蚀性能。从草地植被地上部分对土壤水蚀动力的影响,以及根系增强土壤抗侵蚀性能两个主要方面归纳总结了当前的研究进展,并针对研究中存在的一些亟待解决的问题进行了探讨,以期为更好地利用植被防治土壤侵蚀提供参考。

Taking red skin Jerusalem artichoke as the test material, two root cutting stages (vegetative growth stage and squaring stage) and five root cutting radius(20, 40, 60, 80, and 0 cm) have been designed to investigate the effect of root cutting on tuber yield and quality of Jerusalem artichoke in this study. The results showed that tuber yield was significantly improved by cutting root ( P <0.05) and the highest tuber yield was obtained at 20 cm cutting radius in squaring stage. Cutting treatment significantly increased the soluble sugar content of tuber. Under the treatment of 80 cm during vegetative growth stage, tuber acquired the maximum soluble sugar content while under the treatment of 20 cm soluble sugar content was minimum. Caloric value of tuber was significantly decreased by the treatment of 40 cm cutting during vegetative growth stage and 80 cm cutting during squaring stage, and the rest treatments had no significant influence on it. All treatments had no significant influence on ash except the treatments of 20 cm, 60 cm cutting during squaring stage and 80 cm cutting during vegetative growth stage.

以红皮菊芋( Helianthus tuberosus )为研究对象,在大田极度稀植条件下,通过对营养生长期和现蕾期菊芋根系分别进行0、20、40、60、80 cm垂直切割处理,探讨断根对菊芋块茎产量及品质的影响。结果表明,断根显著提高了块茎产量( P <0.05),且现蕾期20 cm断根使菊芋块茎产量最高;断根显著增加了菊芋块茎的可溶性糖( P <0.05),营养生长期80 cm切割的菊芋,其块茎可溶性糖含量最高,为88.85%,而其含量在20 cm切割条件下最低,为76.18%;除营养生长期80 cm断根对块茎淀粉含量无显著影响外( P >0.05),其他处理均使其降低;营养生长期40 cm断根及现蕾期80 cm断根显著降低了块茎的热值( P <0.05),其余处理对其并无显著影响( P >0.05);除现蕾期20 cm及60 cm断根和营养生长期80 cm断根使块茎灰分显著降低外( P <0.05),其余处理对其并无显著影响( P >0.05)。

【Objectives】Intensive cultivation of dwarfed apple rootstocks is becoming a direction of efficient cultivation for apple at home and abroad. The application of dwarfed interstocks is the main routinein dwarfed apple cultivation, and because of the lack of standard cultivation technique and theoretical basis in 1/2 buried of interstocks, dwarfed apple trees are in low nitrogen utilization, weak tree vigor and fast senescence. Therefore, the effectof different buried depths of interstocks on nitrogen absorption and utilization of dwarfed interstocks and the endogenous hormonewas studied, aiming to provide a scientific basis on appropriate buried depth of the interstocks in apple production. 【Methods】Two-year-old Fuji/SH6/malus hupehensis Rehd trees were selected as materials for studying the nitrogen absorption and utilization by using the 15 N isotope tracer technique. The buried depths were interstocks entirely buried(T1), interstocks 1/2 buried(T2)and interstocks entirely bared(T3)respectively. There were 5 replicates, and 0.5 g 15 N-urea was applied respectively. At the vigorous growing stage and stop growing stage, the hormones in stem tips and fine roots were measured using the method of enzyme-linked immunoassay (ELISA). The whole plants were sampled when the shoot stop growing, and the fresh weight and dry weight of each part were weighed, and the plant total nitrogen and 15 N abundance were detemined.【Results】The results show that the plant growth of interstocks is significantly related with the buried depth, and the height and diameter of plant, total fresh weight and fine root biomass of the T1 treatment are the highest, while those of the T3 treatment are the lowest. The content of endogenous hormonevaries with the buried depth of interstocks, and the contents of gibberellin (GA) and auxin(IAA) of different buried depths are in order of T1>T2>T3 at the vigorous growing stage and the stop growing stage of the new shoot, while the abscisic acid (ABA) contents show an adverse tendency. The ratio of trans-zeatin-riboside(ZR)/gibberellin(GA) in shoot tips of T2 is 8.53% and 6.06% more than those of T1 and T3 at the new shoot stop growing period. The ratios of ABA/GA and ratios of ABA/IAA of stem tips and fine roots during the period are in order of T3 > T2 > T1. The values of (GA+ZR+IAA)/ABA of T1, T2 and T3 in shoot tips are 1.66, 0.83 and 0.71 at the new shoot growing stage. The plant total nitrogen, 15 N uptake and fertilizer utilization rate of T1 treatment are the highest, those of the T2 treatment are in the second place and those of the T3 treatment are the lowest. The Ndff valuesalso varied among treatments, and the value of the T3 treatment is significantly higher than those of the others.【Conclusions】The interstocks 1/2 buried of SH6 reduces the content of growth promoting hormone(IAA and GA)and(GA+ZR+IAA)/ABA ratio, and increases the ZR/GA ratio which relates to flower bud differentiation significantly. The interstocks buried 1/2 treatment can balance the hormone in plant, dwarf the tree, promote the bud differentiation and then increase the absorption and utilization of nitrogen, therefore, the interstocks buried 1/2 of SH6 apple trees present the best in production.

【目的】苹果矮化密植集约化栽培已成为国内外现代苹果生产发展的主流和方向。应用矮化中间砧是当前我国果树生产上采用的主要致矮手段,但矮化中间砧苹果存在氮素吸收利用率低、 树势弱、 易衰老等问题,目前我国对于矮化中间砧的栽培标准尚不统一,生产上大都采用的中间砧埋深1/2的措施也缺乏一定的理论依据。因此,研究中间砧不同埋土深度对苹果幼树内源激素和氮素利用的影响,以期为确定SH6中间砧埋土的最适深度提供理论依据。【方法】利用 15 N同位素示踪技术,以两年生宫藤富士/SH6/平邑甜茶(Borkh cv. Fuji/SH6/M.hupehensis Rehd)为试材,于春梢萌芽前,设置3个埋土深度,其中T1为中间砧全埋,T2为中间砧埋深1/2,T3为中间砧全露,同时每棵施0.5 g 15 N-尿素,5次重复。于春梢旺长期、 春梢停长期,采用酶联免疫法测定茎尖和细根的激素含量;植株停止生长时,整株解析,称量各部分鲜重、 干重,测定植株全氮及其 15 N 丰度。【结果】中间砧埋土深度与植株生长关系密切,株高、 茎粗、 鲜重、 细根生物量均以全埋(T1)最高,全露(T3)最低,且两者差异显著。中间砧不同埋土深度影响植株内源激素含量,不同处理间存在差异,新梢旺长期和新梢停长期茎尖、 新梢中赤霉素(GA)和生长素(IAA)含量均表现为T1>T2>T3,而脱落酸(ABA)的含量则相反; 新梢停长期,T2处理茎尖的玉米素核苷(ZR)/赤霉素(GA)比值比T1和T3处理分别升高了8.53%、 6.06%;各时期茎尖和细根的ABA/GA和 ABA/IAA比值均为T3>T2>T1;新梢旺长期,T1、 T2和T3处理茎尖(GA+ZR+IAA)/ABA比值分别为1.66、 0.83和0.71。植株全氮、 15 N吸收量、 氮肥利用率均以T1处理最大,T2处理次之,T3最小;同一器官不同处理间Ndff%值也存在差异,T3处理显著高于其他处理。【结论】SH6中间砧埋深1/2处理的生长促进型激素GA和IAA的含量以及(GA+ZR+IAA)/ABA比值均降低,并且与花芽分化有关的ZR/GA比值明显升高。中间砧埋深1/2处理既能调节植株体内激素平衡,起到矮化效果,又能促进根系对氮的吸收利用、 提早花芽分化。因此生产上SH6苹果中间砧以埋深1/2的效果最好。

Senecio scandens is a kind of garden liana plant which has both high medical value and ornamental value. Using orthogonal experiment method by 3 levels with 4 factors,the influence of NAA concentration, cutting matrix, cuttings type and processing time on the rooting quality of S.scandens cutting propagation were studied. Cutting rooting quality included rooting rate, average root length and average root quantity. The results showed that NAA concentration had greatest impacts on the rate of rooting quality which followed by processing time, cuttings type and cutting matrix. The rooting quality of S. scandens was the best with NAA concentration 600 mg·L -1 , red-yellow soil midium, stems with buds as cuttings, 1 hour processing time .

千里光( Senecio scandens )是一种药用价值和观赏价值较高的园林藤本植物。采用4因素3水平正交试验设计，以生根率、平均根长和平均生根数为扦插生根质量的指标，并构建生根质量指数，评价总的生根质量，研究NAA浓度、扦插基质、插穗类型和处理时间对千里光无性扦插繁殖生根的影响。结果表明，NAA浓度对生根质量指数影响的效果最大，处理时间次之，插穗类型居第3位，扦插基质影响最小。当NAA浓度为600 mg·L -1 ，扦插基质为红黄壤，插穗类型为带顶芽茎段，处理时间为1 h时，千里光无性扦插繁殖的生根质量最好。

In order to explore the effects of vegetation on seed germination and seedling settlement during the process of ecological restoration, the allelopathy of the extracts of different plant tissue from Populus euphratica with various concentrations (0.04, 0.08, 0.12, 0.16, and 0.20 g·mL -1 ) on the seeds of perennial herb Alhagi sparsifolia was analyzed. The water extracts of P.euphratica have inhibition effects on the seed germination and seedling growth of A.sparsifolia . Different plant tissues and different concentrations of water extracts had different inhibition effects. The water extract of P.euphratica leaves had significantly inhibition effects on seed germination rate and seedling length of A. sparsifoliai The water extracts of stems also had significantly inhibiting effects on seed germination of A.sparsifoliai . The water extract of roots had significantly inhibiting effects on the seedling length of A.sparsifolia .

为了探明生态恢复过程中地表植被对种子萌发和幼苗定居的影响, 分析了胡杨( Populus euphratica )不同组织(根、茎、叶)浸提液和不同浸提液浓度(0.04、0.08、0.12、0.16、0.20 g·mL -1 )对多年生草本疏叶骆驼刺( Alhagi sparsifolia )种子的化感作用。结果表明, 胡杨浸提液对疏叶骆驼刺种子萌发和幼苗生长均具有抑制作用, 不同组织和不同浸提液浓度抑制作用不同:胡杨叶浸提液对疏叶骆驼刺种子的萌发率具有显著的影响;茎浸提液对疏叶骆驼刺种子的萌发率和幼苗的苗长影响显著;根浸提液对疏叶骆驼刺幼苗的苗长影响显著( P <0.05)。

Qira (Cele) oasis is located at the southern fringe of the Taklimakan Desert, the most arid region in northwest of China, where the mean annual precipitation is less than 40 mm and the potential evaporation is about 2600 mm. The perennials Alhagi sparsifolia Shap., Tamarix ramosissima Lebed. and Populus euphratica Oliv. are dominant and important indigenous species in the transition zone between open desert and the Qira oasis. Calligonum caput-medusae Schrenk., which is native to Xinjiang, but not to the re...

沙漠 -绿洲过渡带地区植被的可持续性在防止绿洲沙漠化的过程中非常重要。对过渡带主要植物种骆驼刺 (Alhagisparsifolia Shap)、多枝柽柳 (Tamarix ramosissima L ebed.)、胡杨 (Populus euphratica Oliv.)和头状沙拐枣 (Calligonum caput-medusae Schrenk.)水分关系的研究表明 :4种植物的水分恢复状况良好 ,清晨水势一直较高 ,水分亏缺并不严重。渗透势和正午水势的降低幅度不大 ,变化比较平稳 ,更像是一种生长过程中的结果 ,植物的水分胁迫状况并不明显。 4种植物的水势和渗透势都高于典型的荒漠植物 ,属于中生植物的范围。水分参数的变化显示在同样的环境节律下 ,四种植物在水分生理的变化特征上有一致性。一直很高的 RWCp 值表明植物不能适应剧烈的水分损失和较低的水分含量 ,植物需要稳定充足的水分供应来适应塔克拉玛干极端气候条件下的生长环境。植物对环境胁迫也有各自不同的生理适应特点 ,胡杨的ΔΠ值大 ,能忍受较多的水分损失维持气孔的开放 ;骆驼刺的Ψp 值最高 ,水分亏缺的平衡与恢复效果明显 ;C4 植物头状沙拐枣能维持较高的水势和渗透势，而盐土植物枝柽柳能忍受水势的很大降低。夏季一次性灌溉对骆驼刺、多枝柽柳和胡杨水分状况的改善基本没有影响，对头状沙拐枣有一定的帮助。植物群落和地下水关系密切，过渡带地区地下水位稳定在植物可接触的范围内是保证植物长期存活的关键。4种植物对干旱胁迫的适应为躲避型。