Hydraulic architecture of three Caragana species and its relationship with environmental factors in different habitats of the Inner Mongolian Plateau, China

Hydraulic architecture and its relationship with environmental factors were studied in three Caragana species, namely, Caragana microphylla Lam., C. davazamcii Sancz and C. korshinskii Kom, which were found in different habitats of the Inner Mongolian Plateau, China. The improved flushing method was used in situ on one-year-old twigs for comparing the hydraulic efficiency and the regulating abilities of these three species as well as their mechanisms of regulating water transport to cope with variable environments. The relationship between hydraulic architecture and air temperature followed a linear function with negative slope, whereas the relationships between these parameters with atmospheric humidity were positive. Comparing the hydraulic efficiency among the three seasons, a descending order was given as summer>spring>autumn. In the same season, the hydraulic efficiency of C. korshinskii was higher than that of C. davazamcii, which was in turn higher than that of C. microphylla. It can be concluded from the range of Ks and the slope of two linear functions that there were significant differences in the sensitivity of specific conductivity to environmental factors, both among species and among seasons, with a descending order as summer>spring>autumn. In the same season, C. korshinskii was the most sensitive to the changes of environment, and the sensitivity of C. davazamcii was higher than that of C. microphylla. The results also supported the view that the reduction of hydraulic efficiency because of the embolism in xylem could benefit the plants subjected to water deficit by means of limiting water loss.     

内蒙古高原不同生境三种锦鸡儿属植物的水力结构特征及其对环境因子的响应

以生长在内蒙古高原不同生境条件下的小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿为研究对象,通过定点观测1年生枝条水力结构特征在不同季节的日变化,结合气候因子的相关性分析,比较不同环境条件下3种锦鸡儿植物输水效率与调节能力的高低,进一步分析旱生植物如何通过调整水分传输来适应变化着的环境条件。结果表明,在一定范围内,3种供试植物的水力结构参数都与气温呈显著的线性负相关,与大气相对湿度呈线性正相关关系。同种锦鸡儿植物在不同季节的输水效率比较,总的趋势是夏季〉春季〉秋季;比较同一季节不同种锦鸡儿的输水效率,基本上是柠条锦鸡儿〉中间锦鸡儿〉小叶锦鸡儿;在比导率对环境因子的敏感度方面,季节之间的差异是夏季〉春季〉秋季,物种之间是柠条锦鸡儿〉中间锦鸡儿〉小叶锦鸡儿。一方面日变幅的差异可以体现敏感度的不同,另一方面比导率与大气温度、湿度线性回归方程的斜率也可以体现敏感度的相对高低。这些结果证实了栓塞引起的导水率的下降并不都产生负面影响,相反它具有限流节水的积极作用。     

小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿地理渐变性 Ⅱ.光合特性和水分代谢特性(英文)

研究了不同地区(117.6o ~105.7o E,44.6o ~38.8o N)分布的小叶锦鸡儿(Caragana microphylla Lam.)、中间锦鸡儿(Caragana davazamcii Sancz.)和柠条锦鸡儿(C.korshinskii Kom.)种群的光合特性和水分代谢特性。结果发现:(1)由东向西小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿净光合速率对光合有效辐射的响应增强;净光合速率达到最大值时所对应的空气湿度依次下降;净光合速率达到最大值时所对应的气温依次增加。光合日进程午前优势逐渐升高,光合速率逐渐升高,光能利用率逐渐升高,蒸腾速率逐渐降低,水分利用效率显著升高,叶含水量逐渐降低,植株逐渐采取低蒸腾、高光合的节水对策。这些生理变化与它们分布区的光、温、湿条件相适应。这是小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿发生地理替代分布的生物学基础。(2)小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿光合系统对光合有效辐射、空气湿度和气温的适应都表现出连续性,而且这种连续性与环境的梯度变化相一致。不同种、不同地点光合日进程、日净同化积累值、蒸腾日进程、日蒸腾积累值、水分利用效率以及叶含水量日变化也随经度自东向西呈连续变化。光合特性和水分代谢特性表明小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿的地理替代分布是连续过渡的,是一个连续地理渐变群。     

小叶、中间和柠条三种锦鸡儿的分布式样及其生态适应

确定了小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿3种植物的分布式样:小叶锦鸡儿为蒙古高原东部-F松辽平原西部-华北山地分布种,中间锦鸡儿为东戈壁-鄂尔多斯高原-黄土高原北部分布种,柠条锦鸡儿为南阿拉善-西鄂尔多斯分布种。小叶锦鸡儿适应分布于蒙古高原典型草原带和森林草原带以及华北山地落叶阔叶林带,在草原带高平原上可形成灌丛化草原的景观,在草原带的沙地上可形成以小叶锦鸡儿为建群种的沙地灌丛植被;中间锦鸡儿适应分布于蒙古高原的荒漠化草原及草原化荒漠带、鄂尔多斯高原的典型草原和荒漠化草原带的沙地及梁地上、黄土高原北部的黄土丘坡上,常形成以中间锦鸡儿为建群种的沙地灌丛植被;柠条锦鸡儿则适应分布于草原化荒漠和典型荒漠带的固定和半固定沙地上。近缘的3种锦鸡儿的地带性分布从东至西或从北向南形成明显的有规律的地理替代分布格局。     

Interspecific relationships of Caragana microphylla,C. davazamcii and C. korshinskii (Leguminosae) based on ITS and trnL-F data sets

The taxonomic treatment of Caragana davazamcii Sancz. has been a controversial matter, as its relationship with C. microphylla Lam. and C. korshinskii Kom. is not clear. It was treated as an independent species, or a variety under C. microphylla or C. korshinskii. This study is to examine the interspecific relationship of these three species and the origin of C. davazamcii based on internal transcribed spacer (ITS) and non-coding region of chloroplast trnL-F, combined with morphological data and geographical distribution. The trnL-F sequence of C. davazamcii is identical to that of C. microphylla but differs distinctly from that of C. korshinskii. The high congruence of ITS copies through both direct and cloning sequencing rejects the recent hybridization hypothesis of C. davazamcii between C. microphylla and C. korshinskii. In contrast, two different ITS sequence copies were found respectively in each individual of C. microphylla and C. korshinskii. One of the two ITS sequences in C. microphylla is identical to that of C. davazamcii. This result indicates that C. davazamcii might have taken part in the hybridization of C. microphylla as one parent , or that extensive gene flow might have occurred between these two species, thus resulting in the morphological similarity of them. However, the similarity of some morphological characters of C. davazamcii to those of C. korshinskii might result from the convergent adaptation to their common ecological environment.     

Interspecific Transition Among Caragana microphylla,C. davazamcii and C. korshinskii Along Geographic Gradient. Ⅱ. Characteristics of Photosynthesis and Water Metabolism

The characteristics of photosynthesis and water metabolism of Caragana microphylla Lam., C. davazamcii Sancz. and C. korshinskii Kom. populations in different sites (117.6o-105.7o E, 44.6o-38.8o N) were studied. (1) From the east to the west, the responses of the three species to photosynthetically available radiation (PAR) in net photosynthesis rate increased, the relative humidity of the air which corresponded to the occurrence of maximum photosynthesis rate decreased, and the corresponding air temperature increased. Along the same gradient, the before-noon superiority of the photosynthesis became evident, and the photosynthesis rate and the light use efficiency (LUE ) increased, while the transpiration rate decreased, thus the water use efficiency (WUE ) increased notably, and the leaf water content decreased gradually. From the east to the west, the plants took a water-saving strategy step by step with higher photosynthesis rate and lower transpiration rate. These physiological changes in the plants were adaptable to the conditions of light, temperature and humidity in the habitat of the plants, and might be the biological foundation for the geographical transition among C. microphylla , C. davazamcii and C. korshinskii. (2) The adaptation of photosynthetic system of C. microphylla , C. davazamcii and C. korshinskii to PAR, air humidity and temperature exhibited the interspecific continuity, which was consistent with the environmental gradient. In different species and different sites, the diurnal changes of net photosynthesis rate, the daily cumulative value of net photosynthesis, the diurnal changes of transpiration rate, the daily cumulative value of transpiration, the water use efficiency and the diurnal changes of leaf water content varied with longitudinal descent (from the east to the west). The characteristics of photosynthesis and water metabolism indicated that the geographical transition among C. microphylla , C. davazamcii and C. korshinskii was in gradual change, and these three species formed a geographical cline.     

内蒙古高原西部荒漠区四种锦鸡儿属植物水力结构变化的比较研究

本文采用改良的冲洗法,比较了内蒙古高原西部荒漠区锦鸡儿属(Caragana) 4 种优势植物—柠条锦鸡儿（C. korshinsk）、狭叶锦鸡儿（C. stenophylla）、垫状锦鸡儿（C. tibetica）和荒漠锦鸡儿（C. roborovoskyi）的水力结构日变化和季节变化,目的是了解4种锦鸡儿属植物对荒漠区环境的适应性及其差异。研究发现：4种锦鸡儿属植物的比导率、叶比导率均为早晚高、中午低的单谷日变化曲线;三个季节相比较,夏季的比导率、叶比导率最大;胡伯尔值春季>夏季>秋季。三个季节比导水率日平均值、夏季和秋季的叶比导率、三个季节的胡伯尔值都表现为：柠条锦鸡儿>荒漠锦鸡儿>狭叶锦鸡儿>垫状锦鸡儿;三个季节比导水率日变幅和春季叶比导率表现为：柠条锦鸡儿>荒漠锦鸡儿>垫状锦鸡儿>狭叶锦鸡儿。4个种比导水率日平均值的季节变幅相似。这些结果表明：（1）荒漠区锦鸡儿属植物的水力结构限制了水分运输,使其避免了中午的高蒸腾。（2）荒漠区锦鸡儿属植物通过较高的水分运输效率及较好的叶供水效率适应夏季的高温和强辐射,维持水分平衡;锦鸡儿属植物胡伯尔值的季节变化保证了其在春、夏季快速生长期有较好的水分供应。（3）较高的比导率、叶比导率和胡伯尔值导致了柠条锦鸡儿良好的水分供应和高蒸腾速率,进而导致了柠条锦鸡儿较快的生长速度,这说明柠条锦鸡儿对荒漠环境的适应性好于其它三个种;柠条锦鸡儿的输水效率高,但易发生严重的空穴和栓塞。     

基于ITS序列和trnL-F序列探讨小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿的种间关系

中间锦鸡儿Caragana davazamcii Sancz.的分类处理一直存在争议, 它与小叶锦鸡儿C. microphylla Lam.和柠条锦鸡儿C. korshinskii Kom.的关系尚不清楚。该种被处理为一个独立的种或后两个种的变种。本文利用ITS序列和叶绿体trnL-F序列, 综合形态和地理分布, 探讨了中间锦鸡儿的起源及与另外两个种的种间关系。结果显示, 中间锦鸡儿的trnL-F序列与小叶锦鸡儿完全一致, 而与柠条锦鸡儿有明显差异。中间锦鸡儿的ITS序列高度纯合, 不支持该种可能是杂交起源的假设。相反, 另外两个种的ITS序列均出现多个位点杂合, 克隆后均得到2种不同的序列。中间锦鸡儿的ITS序列与小叶锦鸡儿2种序列中的1种完全一致。该结果表明, 中间锦鸡儿可能作为亲本之一参与了小叶锦鸡儿的杂交起源, 或者基因流是造成这两个种形态相似的主要原因。中间锦鸡儿与柠条锦鸡儿形态上的相似可能是趋同进化的表现。     

内蒙古地区锦鸡儿属3种植物叶脉序比较研究

以内蒙古地区锦鸡儿属3种植物小叶锦鸡儿、中间锦鸡儿、柠条锦鸡儿为对象,利用光学显微镜观察了它们的叶脉序特征,并测定相应的数量指标.结果表明,3种锦鸡儿植物叶片在脉序类型、三级脉类型、高级脉类型、盲脉类型及分枝、网眼形态上没有明显的差别;在各级脉粗细、二级脉夹角、三级脉疏密度以及网眼发育等特征上均表现出随地理分布自东向西逐步递增、递减、密集和趋于完善的变化特点,且有交叉重叠现象;在一级脉的粗细、二级脉的分枝、二级间脉的类型、三级脉疏密等特征上,中间锦鸡儿和柠条锦鸡儿差异较小.研究发现,内蒙古地区锦鸡儿属3种植物在多数叶脉序形态特征和一些数量化指标上没有明显的差异,其亲缘关系较为紧密,但中间锦鸡儿和柠条锦鸡儿在种间关系上可能更为接近;3个种自东向西呈现很强的相似性和渐变性分布,表现出地理渐变的趋势.     

Interspecific Transition Among Caragana microphylla,C. davazamcii and C. korshinskii Along Geographic Gradient. Ⅰ. Ecological and RAPD Evidence

The former plant population survey has shown that three genetically-related species, Caragana microphylla Lam., C. davazamcii Sancz. and C. korshinskii Kom., form a geographical replacement series in Nei Mongol Plateau. The present study on population distribution, taxonomy, morphology, development and genetic structure demonstrated that the geographical distribution of these three species was successive and in gradual change, thus forming a geographical cline which extended from the east to the west of Nei Mongol Plateau. With an analysis of climate change over time, it was considered that the formation of this geographical cline was a result of plant adaptation to its natural environment.     

中国北方温带地区5种锦鸡儿植物的分布模拟

全面收集中国北方温带干旱–半干旱地区5种主要锦鸡儿植物的地理分布资料, 利用ArcGIS 9.0软件绘制现状分布图, 发现小叶锦鸡儿(Caragana microphylla)、中间锦鸡儿(C. intermedia)和柠条锦鸡儿(C. korshinskii)在空间上呈现出从东到西的地理替代分布格局, 继续向西南方向则分布有藏锦鸡儿(C. tibetica), 向西北方向分布有狭叶锦鸡儿(C. stenophylla), 但它们的分布范围又有一定的重叠。整理5种锦鸡儿分布区内的气象台站长期记录, 选择计算15个具有重要生物学意义的水热指标值; 进而用方差分析、多重比较和因子分析相结合的方法, 研究控制这5种锦鸡儿地理分布的主导驱动因子。结果表明: 控制小叶锦鸡儿和中间锦鸡儿间地理分布差异的主导因子是水分因子, 特别是湿度; 水分因子同样是控制中间锦鸡儿和柠条锦鸡儿间地理分布差异的主导因子, 特别是生长季及年降水量; 控制柠条锦鸡儿和藏锦鸡儿间地理分布差异的主导因子是夏季高温, 控制柠条锦鸡儿和狭叶锦鸡儿地理分布差异的是冬季低温。运用耦合BIOCLIM模型的软件包“DIVA-GIS”模拟预测这5种锦鸡儿的现状潜在分布区及未来气候变化的影响, 结果表明: 现状潜在分布区与实际分布区均有很好的一致性; 在CO₂浓度加倍的未来气候情景下, 5种锦鸡儿植物都会向北大幅度迁移, 在我国的分布范围均缩小, 分布格局发生显著变化。用ROC曲线和Kappa统计值法验证模型表明, BIOCLIM的模拟精度较高。     

江西省庐山地区蜻蜓多样性的研究

于2004~2005年对江西庐山地区蜻蜓资源进行调查,通过对春、夏、秋三季蜻蜓多样性的研究,共收集蜻蜓1145只,隶属于10科、35属、52种。种类个体数量均表现为夏季最多,春季次之,秋季最少;属数和科数也是以夏季最多,春季次之,秋季最少。三季多样性指数(H′)的排序为春季(2.7603)>夏季(2.6420)>秋季(2.5601)。     

锦鸡儿属两种植物种子萌发生理研究

对不同种源柠条锦鸡儿、小叶锦鸡儿种子在培养过程中可溶性蛋白质、可溶性糖含量变化及其吸水特性进行分析,以探讨不同种源种子的萌发生理.结果表明:(1)随种子培养时间的延长,各种源柠条锦鸡儿、小叶锦鸡儿种子中可溶性蛋白质、可溶性糖含量呈总体降低趋势,并且0～24 h是种子中可溶性蛋白质、可溶性糖含量降解转化速率较快的时期.(2)各种源柠条锦鸡儿、小叶锦鸡儿种子的相对吸水量随时间变化表现不一,并且柠条锦鸡儿、小叶锦鸡儿的吸水增量有两个明显峰值,第一个峰值均出现在24 h,第二个峰值分别出现在96 h和120 h.(3)各种源柠条锦鸡儿、小叶锦鸡儿的种子活力大小表现为N-5＞X-1＞X2＞N-4＞N1＞N-2＞N-3.     

青海省沙珠玉治沙站17种主要植物叶性因子的比较

国外大量研究结果表明,具有高叶氮含量和低比叶面积的干旱地区植物往往具有较高的水分利用效率。选取青海省沙珠玉治沙站地区17种主要植物(野生9种,人工8种) ,分别测定其比叶面积(SL A) ,单位重量叶氮含量(Nmass)及单位面积叶氮含量(Narea) ,并与贡嘎山湿润森林样带测定数据进行比较分析。结果表明,Nmass随SL A的增加而增加,但Nmass与SL A关系格局在固定沙丘野生多年生草本-灌木植物(类群1,Narea>3.0 g m- 2 )与流动沙丘野生短命草本植物(类群2 ,Narea<3.0 g m- 2 )之间存在策略位移现象,即在相同SL A下,类群1比类群2具有更高的叶氮含量,或在相同Nmass时类群1比类群2具有更小的比叶面积。在8个人工物种中,柠条锦鸡儿、中间锦鸡儿、绵柳和西北沙柳等灌木属于类群1,而甘草、小叶锦鸡儿、柽柳和青杨属于类群2 ,前者比后者具备更好的干旱适应机制,建议在生产上优先考虑前者。流动沙丘野生短命草本植物具有较低的叶氮含量和较高的比叶面积,这一特征与流动沙丘土壤贫瘠及其生长期内降水集中和土壤水分含量相对丰富密切相关。     

Genetic diversity and genetic relationship of Caragana microphylla, Caragana davazamcii and Caragana korshinskii on the Inner Mongolia Plateau, China

C. microphylla, C. davazamcii and C. korshinskii exhibit a geographical replacement series from east to west on the Inner Mongolia Plateau. Currently, there is still a debate about the taxonomic and genetic relationship among these 3 species. We studied the genetic diversity and genetic relationship among these 3 species by analyzing DNA samples of individual plants from within 10 populations with random amplified polymorphic DNA (RAPD) markers. We identified 678 RAPD loci in total, of which all were polymorphic (PPB = 100%). There were 41 unique loci (6.05%). In general, a trend presented that the genetic diversity of these species decreased from east to west. Further, the genetic diversity was significantly negatively correlated with the local annual mean temperature. Analysis of molecular variation (AMOVA) showed that the genetic variation among these 3 species was only 6.08% of the total genetic variation. Between the species, the genetic variation was insignificant (P = 0.9961). The proportion of genetic variation among populations within each species was 11.90% (P < 0.001) of the total genetic variation, and the total genetic variation mainly existed within the populations (82.02%). Estimated with Shannon's index, genetic differentiation within the populations (Hpop/Hsp) was 0.8013, the coefficient of gene differentiation (Gst) was 0.1603, and the gene flow index (Nm) was 2.6192. This, thus, indicates that there is relatively high gene flow among these populations, and that these 3 species are crossbreeding. The genetic diversity level and the population distribution pattern showed geographic continuity to some extent.     

三种锦鸡儿属植物水力结构特征及其干旱适应策略

水分胁迫是干旱半干旱区限制植物生长的主要因素。以干旱半干旱区的3种锦鸡儿属植物为研究对象,从生态适应策略角度来分析3种锦鸡儿植物产生生态分离的原因。对三种锦鸡儿属植物茎干叶片的显微结构、生理功能(导水率、光合速率以及水分利用效率)进行测定,并统计了3种锦鸡儿植株的形态特征,如一、二级枝的直径、长度、末端叶面积。结果表明:三种锦鸡儿属植物都能形成较小的导管直径来适应旱生环境,但是在导水结构上又表现出一定的差异性。中间锦鸡儿的导管直径最小,次脉密度和最大净光合速率最大;柠条锦鸡儿的导管直径、叶片厚度和比叶重(LMA)最大。小叶锦鸡儿在导水率下降50%时的水势(P_(50))最大,水分胁迫时极易发生栓塞,但正是由于导管的栓塞降低了水分运输效率,使其在旱生环境中能够通过减少水分的供应来降低水分的丧失,从而保证自身生长的水分需求;而中间锦鸡儿则主要通过减小导管直径来适应旱生环境;柠条锦鸡儿的水分利用效率最高,抗栓塞能力最强,抗旱性最好,同时柠条锦鸡儿可以通过减少蒸腾面积来减少水分的丧失。植物的导管直径大小、叶片厚度、LMA、叶脉密度对植物导水速率、光合速率等生理功能都有一定的影响。     

科尔沁沙地4种植物抗旱性的比较研究

对科尔沁沙地小叶锦鸡儿,紫穗槐,差巴嘎蒿和胡枝子4种植物的若干水分生理生态指标进行了测定。结果表明,小叶锦鸡儿具有低水势,高水力和束缚水／自由水比及水分利用效率,抗旱性强;紫穗槐的各项指标与小叶锦鸡儿相反,抗旱性最差;差巴嘎蒿虽然水势较高,但它的持水力高,束缚水／自由水比和水分利用效率都较高,抗旱性也较强,但次于小叶锦鸡儿;胡枝子的水势和持水力较低,束缚水／自由水比及水分利用效率一般,它的抗旱性强于紫穗槐,但比差巴嘎蒿差。     

柠条根系中丛枝菌根真菌的季节性变化及影响因素

采用传统染色检测与PCR-DGGE相结合的方法,研究了柠条根系丛枝菌根真菌(AMF)的季节性变化, 并利用主成分分析(PCA)和典范对应分析(CCA)分析了土壤因子与AMF季节变化之间的关系.结果表明: 柠条根系AMF总侵染率、丛枝侵染率、泡囊侵染率和土壤孢子密度均具有显著的季节性差异. 总侵染率从春季至秋季呈下降趋势,其他指标呈上升趋势. 春、夏、秋3个季节的柠条根系中共检测出9种AMF分子种,但每个季节的AMF群落组成、多样性指数均有一定的差异.主成分(PCA)和典范对应分析(CCA)表明,随着土壤总氮、总磷和有机碳的增加,泡囊侵染率减少;随着土壤含水量和速效磷的降低, 土壤AMF孢子密度增加;根系内AMF群落组成的季节性差异主要受土壤总磷、速效磷和有机碳的影响.     

半干旱黄土丘陵区沙棘和柠条水分利用与适应性特征比较

对半干旱黄土丘陵区坡地多年人工沙棘(Hippophae rhanvnoides)与柠条(Caragana korshinskii)林的土壤水分状况、生产力月动态以及光合生理和水势日变化特征进行比较．结果表明,沙棘与柠条深层土壤均存在不同程度的旱化现象,沙棘林在季节性土壤水分补偿深度和对深层低土壤水分的利用能力方面要强于柠条林．沙棘林的年度生产力大于柠条林．沙棘能够随着土壤水分条件的改善,而提高水分利用效率;柠条具有高光合特别是高蒸腾的光合生理特征,叶片水分利用效率较沙棘低．沙棘与柠条均兼具有御旱性与耐旱性,但沙棘对干旱的适应方式更积极主动．     

生态脆弱带不同区域近缘优势灌木的生理生态学特性

小叶锦鸡儿、中间锦鸡儿和柠条锦鸡儿分别为中国北方生态脆弱带典型区域——科尔沁沙地、毛乌素沙地和腾格里沙漠的优势灌木。为了探讨生长在地理位置相距很远的不同气候类型区、但亲缘关系较近的沙漠植物种之间特性的差异及近缘种间引种成功的可能性 ,对 3种灌木在原产地和引种地 (腾格里沙漠 )的气体交换、叶绿素荧光参数、β胡萝卜素和脯氨酸累积等特性进行了对比研究 ,结果显示 :各区优势灌木的气体交换特征不同 ,主要依照区域光照和温湿条件的不同组合而变化 ,各区域的环境条件组合最利于其建群种的生长 ;引进种对引种地环境变化的反应调节较乡土种敏感 ;地理位置相距较近的近缘种间生理特性相近 ,引种易于成功