秦岭和黄土高原地区锦鸡儿属的表征,分支和生物地理学的探讨

选用锦鸡儿属在秦岭和秦岭以北的２０余种和５９个形态性状作为分析基础。表征图和分支图共同提示出羽状和掌状叶类群形成两大类。分支图说明了树锦鸡儿Ｃ．ａｒｂｏｒｅｓｃｅｎｓ和柄荚锦鸡儿Ｃ．ｓｔｉｐｉｔａｔａ等为原始类群。沿树锦鸡儿的分布区,本属植物向西和西南方向适应辐射成以温度和降水为主导因子的生态序列：（１）森林种→森林草原种→草原种→荒漠种,森林种→高寒山地种;（２）湿润地带→亚湿润地带→半干旱地带     

锦鸡儿属分析生物地理学的研究

将锦鸡儿属（Caragana）植物分布区划分成13个。在分支系统学基础上,进行了分布区的成分分析。以种类和系为分布特征,进行分布区的聚类分析和最小生成树分析。分布区分支图、表征图和最小生成树从不同方面表达了分布区的关系。锦鸡儿属的分布区被分成东亚和古地中海两大部分。其中分别来自这两部分的前苏联远东-我国东北与阿尔泰-萨彦岭分布区有密切关系。基于分布区分支图,属的分布区分别由这两个分布区衍生,同时结合属的种系发生关系,推断本属可能起源于东西伯利亚,时间为第三纪中新世末-上新世。生态适应上,分类群是由东部温带中生性类型向西部旱化和寒化方向发展的。     

锦鸡儿属植物区系成份分析

锦鸡儿属(Caragana Fabr.)属蝶形花科山羊豆族,是温带亚洲的代表属之一。本文对锦鸡儿属已知种类的区系成份进行了研究,将105种植物共划分为20个分布区类型,其中包括:(1)青藏高原分布;(2)沿喜马拉雅分布;(3)云贵高原分布;(4)云贵高原—华北分布;(5)秦岭山地分布;(6)华北分布;(7)中国东北分布;(8)蒙古高原分布;(9)西伯利亚阿尔泰分布;(10)亚洲中部分布;(11)西亚分布;(12)天山山地分布;(13)帕米尔—阿赖依分布;(14)小亚细亚—里海—哈萨克斯坦分布;(15)准噶尔—哈萨克斯坦分布;16)塔尔巴哈台—准噶尔—蒙古分布;(17)准噶尔特有分布;(18)昆仑山特有分布;(19)黑海—西西伯利亚分布;(20)欧洲—高加索分布。统计结果表明:属青藏高原分布的种类最为丰富,有18种,占总数的17.16％,沿喜马拉雅分布次之,共计12种,占总数的11.45％;再次之是中国华北分布和天山山地分布,均为10种,占总数的9.54％。通过区系分析可以清晰地看出:本属在中国,的分布很广,种类也很多,共计80种,约占全属总数的76.32％。中国特有种也很丰富,共计43种,占全国分布总数的一半以上(53.75％),占本属总数的40.95％。     

锦鸡儿属分析生物地理学的研究

将锦鸡儿属（Ｃａｒａｇａｎａ）植物分布区划分成１３个。在分支系统学基础上,进行了分布区的万分分析。以种类和系为分布特征,进行分布区的聚类分析和最小生成树分析。分布区分支图、表征图和最小生成树从不同方面表达了分布区的关系。锦鸡儿属的分布区被分成东亚和古地中海两大部分。其中分别来自这两部分的前苏联远东－我国东北与阿尔泰－萨彦岭分布区有密切关系。基于分布区分支图,属的分布区分别由这两个部分分布区衍生,同     

青藏高原和喜马拉雅地区锦鸡儿属植物的地理分布

锦鸡儿属Caragana是一个典型的温带亚洲分布属。本属在青藏高原和喜马拉雅约有24种1变种,约占整个属的1／3。这些种类几乎全部处于演化高级阶段,且既有叶轴宿存类群,也有假掌状叶类群。反映出种的分化很活跃,在横断山地区形成本属的分布中心、分化中心。本区内绝大多数种类是特有分布。替代现象主要受气候、植被变化作用,沿横断山和喜马拉雅分布的长齿系Ser. Bracteolatae Kom．是一个典型的替代分布类群。锦鸡儿属植物生态适应性很强,可在其生长的灌丛中形成优势种。 寒化和旱化现象十分突出,它们有一系列森林种、草原种和荒漠种及相关的形态变异。用锦鸡儿属植物进行青藏高原和喜马拉雅区域内的分布区关系分析及最小生成树MST和特有性简约性分析(PAE),表明横断山地区特别是其北部是本属植物的一个地理结点。以此沿横断山向北部唐古特和西部藏东南适应性辐射。横断山和西喜马拉雅联系微弱,看不出植物长距离扩散的踪迹,大多是由于生态因子限制而产生的隔离。虽然本区不可能是锦鸡儿属的起源地,然而,通过本区与邻近地区的地理联系,可推测它们在我国适应性辐射方向是从东北向西南。结合豆科蝶形花亚科其它属化石记录及其分布区局限在温带亚洲等现象,认为锦鸡儿植物是一组特化、晚近衍生的类群,起源于北方东西伯利亚晚第三纪中新世后期至上新世。     

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。     

锦鸡儿属植物在鄂尔多斯高原区系和植被中的作用

锦鸡儿属植物在鄂尔多斯高原分布有9种。是物种多样性相对丰富的一个地区。其中中间锦鸡儿Caragana korshinskii var. intermedia,在鄂尔多斯高原东部和毛乌素沙地被当作优选的、广泛栽培的、习见的固沙和水土保持灌木树种。从植物区系成分上分析,主要是中亚成分和东亚成分,中亚成分有蒙古高原分布,阿拉善分布,戈壁-蒙古分布,内蒙古草原-黄土高原分布;东亚成分有华北分布,华北-青藏高原分布,以及蒙古高原南部-青藏高原成分。这些成分充分反映出这一地区与相邻地区的联系和过渡性。形成明显替代现象是本区东部的C. korshinskii var. intermedia与西部的C. korshinskii之间的替代。灌木种类是鄂尔多斯高原的优势生活型植物。在鄂尔多斯高原分布的14个主要灌木群落中,其中有4个重要的锦鸡儿群落,即中间锦鸡儿群系Form. Caragana korshinskii var. intermedia,狭叶锦鸡儿群系Form. Caragana stenophylla,柠条锦鸡儿群系Form. Caragana korshinskii,藏锦鸡儿群系Form. Caragana tibetica。中间锦鸡儿群系为优良的固沙和水土保持灌木。藏锦鸡儿群系则主要分布在西鄂尔多斯,为自然分布。在硬地及覆沙梁地形成高达40~80 cm的小沙丘包,在灌丛中占绝对优势,是锦鸡儿属植物在鄂尔多斯高原最典型的景观之一。这些锦鸡儿属植物群落对于揭示植被从东到西典型草原-荒漠化草原-荒漠的地带性分布具有典型的表征意义。     

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。     

一种改进的PAE方法及其在锦鸡儿组(锦鸡儿属)特有性分析中的应用

针对特有性简约性分析（PAE）不足之处,提出一个新的改进分析方法。主要区别是,新方法对分布区内分类群区分了原始和演化,相应地编码为0／1;为了获取分类群原始和演化的特性,分析以分类群分支图为基础。新方法是系统发育与地理分布相统一原理的一个具体的定量化探讨。用新方法分析了豆科锦鸡儿属锦鸡儿组15种,结果表明新方法优于以前的PAE方法。用新的改进方法分析得到的可能的祖先分布区是原始类群树锦鸡儿和一大类属内原始类群的分布区。与目前属的起源问题的一般观点相一致。     

锦鸡儿属植物4个种的核型分析

对4种锦鸡儿属(CaraganaFabr.)植物的核型进行了分析,得出4种染色体核型:秦晋锦鸡儿(C.purdom iiRehd.)染色体数为2n=16,其核型公式为2n=16=16 m(4 SAT);小叶锦鸡儿(C.m icrophyllaLam.)染色体数为2n=16,其核型公式为2n=16=14 m(2 SAT) 2 M;中间锦鸡儿(C.interm ediaKuang et H.C.Fu)染色体数为2n=18,其核型公式为2n=18=16 m(4 SAT) 2 M;树锦鸡儿(C.arborescensLam.)染色体数为2n=20,其核型公式为2n=20=20 m(4 SAT)。由此可推测:中间锦鸡儿可能为小叶锦鸡儿和树锦鸡儿或秦晋锦鸡儿和树锦鸡儿的中间类型或杂交种,也可能是具有递增染色体基数的不同种。     

西伯利亚嵩草及其相关类群的植物分类学及植物地理学研究

研究了产于西伯利亚的西伯利亚嵩草Kobresia sibirica (Turcz.ex Ledeb.) Boeck.,产于北美的K.hyperborea Porsild和K.macrocarpa Clokey。三者之间无显著差异,并且它们的雌花都具有由一至三枚小鳞片组成的花被。因此,它们为同种植物, K.hyperborea包括其变种var.alaskana Duman和var.lepagei Duman及K.macrocarpa被降为西伯利亚嵩草的异名。西伯利亚嵩草分布于亚洲和北美洲的北极和亚北极地区,可能起源于亚洲,由东西伯利亚通过白令海峡散布到北美。     

锦鸡儿属植物分布研究

依据每个种的地理分布范围,确定了出六种分布类型,并编制了属的分布密度图。结合各类发布特点及其形态特征,认为东亚西南部为其起源中心,而中亚来其变异分化中心。起源第三纪中期的原始类群Ser.Caragana,在寒旱主要压力下分化适应,形成现代化布格局。     

Morphological and ecological characteristics of moose, <Emphasis Type="Italic">Alces</Emphasis> cf. <Emphasis Type="Italic">alces</Emphasis> (Artiodactyla), from the southeast of Western Siberia in the Late Neopleistocene and Holocene

Fossil, subfossil, and recent materials of moose from the southeast of Western Siberia, including the remains of the skull, antlers, mandibles, and postcranial skeleton, has been analyzed. Adaptive features revealed in the structure of the mandible (a high pars dentalis) suggest that forests were a less typical habitat for ancient moose, compared to recent A. a. alces. The high pars dentalis of the mandible and the shape of antlers, with a long basal part and bifurcated spatula, are indicative of their close relation to A. americanus from Eastern Siberia. Thus, moose from the Late Neopleistocene and Holocene appear to represent the same species as A. americanus. It cannot be excluded, however, that A. cf. alces is a special type of European A. a. alces moose in which the characters convergent to Eastern Siberian A. americanus developed independently, due to habitation in similar open (forest-steppe and steppe) landscapes.     

A Dispersal and Vicariance Analysis of the Genus Caragana Fabr.

The genus Caragana Fabr., consisting of approximately 70 species, has a temperate Asian distribution and occurs mainly in the drought and cold regions of the northwestern and southwestern Tibetan Plateau of China. The distribution pattern of the genus was investigated using dispersal-vicariance analysis （DIVA）, The results indicate that vicariance versus dispersal plays a major role in the evolution of the genus and that short-distance dispersal also exists. There is no fossil record of this genus. Therefore, Caragana is inferred as an advanced taxon in terms of its limited temperate Asian distribution. Based on the morphological variation and ecological adaptation in Caragana, the generic speciation is postulated to be related to the uplifting of the Tibetan Plateau and to the increasing arid conditions of Central Asian lands since the Neogene. The Mongolian Plateau and the Tibetan Plateau are hypothesized as the barriers of vicariance between East Asia and western Central Asia.     

Two new species of Gomphidius from the Western United States and Eastern Siberia

Study of the genus Gomphidius from recent material from Asia and North America has been carried out using traditional taxonomy combined with molecular systematics. Two new species of Gomphidius (G. borealis and G. pseudoflavipes) are described, one from Eastern Siberia and a second from rarely collected habitats in the Western United States. One taxon has the longest spores reported for the genus and the second species appears to be associated with a Siberian larch.     

Genomic signature of successful colonization of Eurasia by the allopolyploid shepherd's purse (Capsella bursa‐pastoris)

Polyploidization is a dominant feature of flowering plant evolution. However, detailed genomic analyses of the interpopulation diversification of polyploids following genome duplication are still in their infancy, mainly because of methodological limits, both in terms of sequencing and computational analyses. The shepherd's purse (Capsella bursa‐pastoris) is one of the most common weed species in the world. It is highly self‐fertilizing, and recent genomic data indicate that it is an allopolyploid, resulting from hybridization between the ancestors of the diploid species Capsella grandiflora and Capsella orientalis. Here, we investigated the genomic diversity of C. bursa‐pastoris, its population structure and demographic history, following allopolyploidization in Eurasia. To that end, we genotyped 261 C. bursa‐pastoris accessions spread across Europe, the Middle East and Asia, using genotyping‐by‐sequencing, leading to a total of 4274 SNPs after quality control. Bayesian clustering analyses revealed three distinct genetic clusters in Eurasia: one cluster grouping samples from Western Europe and Southeastern Siberia, the second one centred on Eastern Asia and the third one in the Middle East. Approximate Bayesian computation (ABC) supported the hypothesis that C. bursa‐pastoris underwent a typical colonization history involving low gene flow among colonizing populations, likely starting from the Middle East towards Europe and followed by successive human‐mediated expansions into Eastern Asia. Altogether, these findings bring new insights into the recent multistage colonization history of the allotetraploid C. bursa‐pastoris and highlight ABC and genotyping‐by‐sequencing data as promising but still challenging tools to infer demographic histories of selfing allopolyploids.     

Pollen Morphology and Its Taxonomic Significance of Caragana Fabr. (Fabaceae) from China

Pollen grains of thirty one species and two varieties of the genus Caragana Fabr. were observed under LM and SEM.The results revealed that the pollen exine ornamentation of the species examined could be divided into two types: perforate and reticulate.The later type consists of two subtypes according to lumina size and muri width. In the first subtype the lumina is round with d iameter equal to muri width,and the exine is perforate in two polar areas,while in the second subtype lumina is irregular or polygonal,with diameter sm aller than muri width.The pollen volume was divided into four types.The genus Caragana is a natural group which was indicated by the general resemblance of pollen morphology. In this genus the pollen morphological classification was not in concordance with the arrangement of the sections and series except Ser.Pygmeae and some species. The pollen variation at infraspecific level was obvious,especially the species distributed in Qinghai Xizang Plateau, such as C.jubata, C.bicolor and C. erinacea . The evolutionary trend of pollen morphology is from perforate to reticulate, which is congruous with the evolution from the pinnate leaf group to the almate leaf group in the genus.