中国茜草属sect.Oligoneura的形态计量学研究

茜草属为茜草科模式属,全球约80种,中国有近一半的物种,是茜草属的重要分布中心,大部分隶属于sect.Oligoneura。但是,该组内各种间的形态特征错综复杂,依靠单个性状不易划定种间界限。该研究在全面衡量sect.Oligoneura组内各种间形态特征的基础上,选取该组20种共171份标本,对其3个数量性状和28个定性性状进行聚类分析和主成分分析。结果表明:在主成分分析中,前3个主成分累积贡献率有46.88%,性状的累积贡献率增长并不明显,但该结果仍与聚类分析结果一致。对前3个主成分贡献较大的特征包括叶形(叶长宽比)、叶柄长度、叶脉、每轮叶片数和生活型等,这些形态性状也是该属传统分类学中重要的物种鉴定特征。该研究结果与分子系统发育结果基本一致,支持该组内ser.Chinenses、R.mandersii group、R.angustissima group和R.siamensis group类群的划分,但并不支持ser.Cordifoliae单独成系。sect.Oligoneura内除少数物种外,大部分物种界限均比较清晰。形态计量学研究为sect.Oligoneura甚至茜草属的物种鉴定与划分提供了重要的参考意义。     

淫羊藿属植物的数量分类学研究

通过观测淫羊藿属植物的30个质量性状和15个数量性状,利用聚类分析和主成分分析的方法研究淫羊藿属属下类群的分类关系。结果表明:(1)聚类分析结果将淫羊藿属中国种类划分为大花类群和小花类群,支持Stearn对Sect.Macroceras、Sect.Polyphyllon和Subg.Rhizophyllum的处理,但认为Sect.Epimedium的分类地位尚需进一步探讨。(2)主成分分析结果显示,性状的累积贡献率不是很高,前3个主成分累积贡献率为51.86%,这可能与本属植物演化过程中性状变异的多样化和复杂化相关,但由主成分分析的结果仍可以看出中国种类被划分为大花类群和小花类群。研究认为,花瓣与内萼片长度比、花瓣是否具距、萼片轮数等作为主成分反映的性状对淫羊藿属分类具有重要价值。     

苜蓿属和胡卢巴属植物的形态特征及数量分类研究

为研究苜蓿属(Medicago L.)与胡卢巴属(Trigonella L.)间的亲缘关系,寻找两属间的分属依据,解决中间过渡类群的分类归属问题,对苜蓿属与胡卢巴属种类的种皮结构和花粉形态特征进行了观察和测量,并以苜蓿属和胡卢巴属植物的40个形态性状为依据、应用数量分类方法对供试的16个种类进行了聚类分析(UPGMA)和主成分分析(PCA).此外,还根据具有重要分类学意义的形态性状,编写了供试的苜蓿属和胡卢巴属16个种类的分类检索表.观察结果表明,供试的两属植物(11种)的种皮结构基本相同,均由栅栏组织细胞、厚壁细胞和薄壁细胞组成,但胡卢巴属种皮的帽状结构和栅栏组织的厚度均小于苜蓿属.供试的两属植物(9种)花粉形态特征相似,均为椭球形或近球形,赤道面观为椭圆形,极面观为三裂圆形;极轴和赤道轴长分别为22.67～34.67 μm和17.34～31.60 μm;花粉表面纹饰较简单,呈小穴状.种皮结构和花粉特征显示两属的亲缘关系较近,仅种皮结构中的帽状结构差异具有一定的属间分类学意义.聚类分析结果表明,在欧氏距离10.85处,供试的苜蓿属(11种)和胡卢巴属(5种)的16个种类被划分为2组,A组均由胡卢巴属种类组成,B组均由苜蓿属种类组成;在欧氏距离9.32处,B组可被进一步划分为3个亚组,所包含的种类分别为苜蓿属的阔荚亚属(Subgen. Platycarpos D. F. Cui)、镰荚亚属(Subgen. Medicago Tutin)和天蓝苜蓿亚属(Subgen. Lupulina Gressh.)的种类.主成分分析结果表明,前3个主成分的累积贡献率较低,仅57.50%;在前3个主成分中,果实和小叶的长宽比、花萼长和被毛状况、茎和小叶的被毛状况、小叶尖形状、花序长等相关性状的绝对权重值均在0.6以上,具有重要的分类学意义;基于前2个主成分所做的二维散点图中供试的16个种类组成4个表征类群,与聚类分析结果一致.     

中国原产石蒜属植物的数量分类和主成分分析

应用数量分类学方法对中国原产石蒜属13种2变种的35个性状进行Q、R聚类分析和主成分分析,探讨国产石蒜属植物种间的亲缘关系,并对分类性状进行评价。研究结果显示,Q型聚类可分为2个大类和8小类,安徽石蒜与长筒石蒜的亲缘关系很近,认为将其作为长筒石蒜的变种更为合适,同时支持玫瑰石蒜、红蓝石蒜、乳白石蒜、江苏石蒜、稻草石蒜的杂交起源观点。R型聚类可分为7个组;经主成分分析,35个性状可综合为5个主成分,其累积贡献率达82.55%,根据这5个主成分与性状间的相关性,选出影响比较大的16个性状,其中鳞茎形状、花被片宽和雄蕊长/花被片长的比值最为重要,可作为大类群划分的依据,而花被片是否具条纹、花丝颜色、花色、花葶粗、幼叶尖端及边缘颜色、种子有无等可作为物种划分的重要依据。     

橡胶草及其同域近缘种表型多样性研究

对蒲公英属橡胶草及其同域10个近缘种共13份材料的59个表型性状(数量性状24个,质量性状35个)进行了观测,通过方差分析、因子分析和聚类分析对其形态性状多样性和种间亲缘关系进行研究,以明确各表型性状对种质分类的重要性及其贡献,为橡胶草品种选育及蒲公英属植物的分类和种质资源保存利用提供依据。结果显示:(1)13份蒲公英属种质资源在数量性状上变异系数在7.50%~55.00%之间,平均为28.25%,多样性指数在1.157~2.032之间,平均为1.663,具有丰富的表型多样性。(2)质量性状方面,变异系数的变化范围在20.40%~67.44%之间,多样性指数变化范围在0.271~1.672之间,平均为1.136,总体上是数量性状形态多样性指数大于质量性状。(3)59个性状的主成分分析中前7个主成分的累计贡献率为84.767%,花部形态变异是蒲公英属植物表型分化的主要因素。(4)利用欧氏距离进行的Ward’s聚类分析结果表明,13份材料可分为4大类群,同一地区的大部分种聚在一起,呈现出一定的地域性,亲缘关系较近;但来源于3个居群的橡胶草却被划分在2个类群中,表现出较远的亲缘关系。研究表明,蒲公英属植物种质材料具有丰富的质量和数量性状变异,表型多样性丰富。     

瑞香属和荛花属的数量分类研究

瑞香属和荛花属为瑞香科瑞香亚科的落叶或常绿灌木,中国西南部是瑞香属和荛花属的重要分化中心。全世界共有瑞香属95种、荛花属70种,中国分布有瑞香属52种、荛花属49种。瑞香属和荛花属的分类学研究一直存在不同程度的分歧。花盘形状和果实类型在传统分类中一直是区分瑞香属和荛花属的典型特征,而花盘形态和果实类型在2个属中存在交叉和过渡,部分植物分类学家根据这些特征将两个属进行过不同程度的归并。该研究采用数量分类法对瑞香属77种(变种)和荛花属62种(变种)植物,选取32个形态学性状进行聚类分析和主成分分析。结果表明:聚类分析和主成分分析均显示两属均未形成单系类群。在主成分分析中,前3个主成分分析的贡献值为35.56%,传统分类中用来区分两属的花盘形状、叶序及果实类型等特征对前3个主成分贡献相对较小,因此,传统分类学中对这两个属进行区分的性状并没有典型的分类学意义。同时,聚类图和主成分分析得到的散点图均不能将这两个属区分开来。数量分类研究结果显示两属植物存在明显的交叉,支持瑞香属和荛花属不是两个独立自然类群的观点。     

西北地区杨属的数量分类

本文应用聚类分析和主成分分析的方法对西北产的杨属29个种或种下分类单位进行了研究。聚类分析中选取了71个特征性状采用了相关系数基础的不加权算术平均配对法(UPGMA)法进行了运算。本文共观测了2576个样本(包括芽、短枝、叶片、雄花、蒴果)的各项特征。数量分类的结果将杨属划分为三个亚属及五个组。通过数量分析的方法,对一些有争议或有疑难的种或变种,如额河杨、河北杨、毛白杨……、小叶杨,进行了讨论。本文还对五个组之间的关系和仅根据营养器官特征分类的可靠性进行了探讨。最后对数量分析的方法也进行了讨论。     

国产青冈属的数量分类学研究

观测了中国青冈属(Cyclobalanopsis Oersted)77个种近千份标本,选取包括叶柄、小枝、叶片、毛被、裂齿、坚果、壳斗等70个特征,应用因子分析和聚类分析的方法研究青冈属属下分类.因子分析借助主成分分析方法,从70个原始性状变量中筛选归纳出5个关键形态因子14个变量,并以此作为聚类分析的新变量,选取欧式距离系数和非加权平均数法(UPGMA)进行聚类.聚类分析和主成分分析的结果将国产青冈属划分为2个组5个亚组,与以前的形态分类吻合.因子分析结果表明:叶型、环带裂齿、壳斗毛被等性状对青冈属分类具有较重要的意义.还对青冈属2个大组和5个亚组之间的关系进行了探讨,并对用于分类的特征因子的可靠性进行了讨论.对青冈属一些有争议或存疑的种或变种(如青冈、龙迈青冈、长叶粉背青冈、黄枝青冈和滇青冈等)的关系也进行了讨论.     

泥炭藓植物数量分类的研究

本文用聚类分析和主成分分析方法对泥炭藓属的14个种及一个变种进行了数量分类的研究。通过对15个OTU×42个性状的原始数值矩阵的标准化及复杂运算后,其结果表明:1.由聚类过程所得到的树系图,并结合生物分类学的实际意义,将泥炭藓属分为6个组,即Section Sphagnum、Sect.Squarrosa、Sect.Acutifolia、Sect.Subse-cunda、Sect.Polyclada及Sect.Cuspidata。其结果与经典分类的结果基本上是一致的。2.通过对泥炭藓主要性状的因子分析和主成分排序,初步反映了各性状所占的信息比例,找出了泥炭藓植物分类中所应依据的重要性状。3.通过对泥炭藓植物的排序,进一步阐明了泥炭藓属内的各个种之间的系统位置。本文首次将数量分类用于泥炭藓植物,通过研究,认为该方法用于其它苔藓植物也是可行的,这对苔藓植物定量地、准确地表现分类群的系统位置及亲缘关系,将有一定的参考价值。     

三倍体芒草自然杂交后代数量性状遗传多样性研究

以三倍体芒草奇岗的自然杂交后代为研究对象,对后代群体的16个数量性状分别进行变异分析、主成分分析和聚类分析。研究结果表明:(1)该杂交群体的变异系数在14.41%~151.85%之间,平均变异系数为51.22%,说明杂交后代变异广泛。(2)主成分分析结果表明,前4个主成分反映原变量的80.206%的信息。第1主成分贡献率为48.74%,较大载荷性状有分蘖数、丛径、基部周长、单株鲜重和单株干重;第2主成分贡献率为16.313%,较大载荷性状有外径、内径、单茎干重、单茎鲜重和含水量;第3主成分贡献率为7.775%,仅有腋芽数一个较大载荷性状;第4主成分贡献率为7.378%,仅叶片数一个较大载荷。(3)聚类分析结果表明,将66份奇岗自然杂交后代和6份母本奇岗种质分为4大类。第Ⅰ类材料因本身各性状不足,产量很低,不适合筛选高产种质;第Ⅱ类材料各性状变异系数普遍较小,性状稳定,适合作为育种的备选类群;第Ⅲ类材料因枯黄较少,更适合做发酵类能源草或青贮牧草;第Ⅳ类材料生物产量因子及其产量构成因子都明显优于母本,是较好的育种材料。以上研究结果对筛选芒属植物优良种质、创新芒属植物种质资源有积极意义,并为芒属植物多倍体育种提供理论依据和材料基础。     

中国薹草属黑穗薹草组的数量分类研究

对中国薹草属黑穗薹草组Sect.Racemosae及外类群冻原薹草组Sect.Frigidae共20种3变种采用38个形态特征进行了数量分类研究。聚类分析结果表明,黑穗薹草组应是一个自然分类群;支持了《中国植物志》将两对相似种：乌拉草（Carer meyeriana）与红原薹草（Carer hongyuanensis）、膨囊薹草（Carex lehmanii）与五台山薹草（Carex montis-wutaii）分别处理为种的观点。主成分分析结果表明,本组的分类特征较为稳定与集中,本组主成分分析散点图与聚类分析的分类结果大致吻合,并表明有关小坚果、果囊、鳞片、主茎叶和苞片的性状在本组的分类中起到了主要作用。     

A phenetic study of the taxonomic delimitation of Quercus acutifolia and Q. conspersa (Fagaceae)

A phenetic study ofQuercus acutifolia andQ. conspersa (Fagaceae) is carried out. The study was based on morphological characters, and included cluster analysis and principal component analysis. The results revealed that the characters employed so far to separateQuercus acutifolia andQ. conspersa seem to be quite unreliable. Nevertheless, both species can still be recognized as taxonomically different entities, although mostly based on characters of leaf margins. We propose that the individuals that have leaves with dentate-aristate margins correspond toQ. acutifolia, whereas those that have leaves with entire and not dentate-aristate margins belong toQ. conspersa.     

Further geometric morphometric analysis on the genus Eysarcoris (Hemiptera: Pentatomidae) from China

Further geometric morphometric analysis of the genus Eysarcoris was done based on the former studies to classified the nine Eysarcoris species from China.In this study,six characters,such as forewing,hindwing,pygophore,head,pronotum and scutellum,were selected to investigate the shape variation of Eysarcoris.Significant divergence in the shapes of the six characters was observed among the species (p ＜ 0.05).For all methods,phenetic similarity based on the six characters agrees with the current status of the genus.The cluster analysis of eight species are consistent with the traditional morphological studies.CVA analysis also shows that the values of the six characters are not equal in taxonomy.Pygophore,forewing,hindwing and pronotum play more important roles in the classification.     

Numerical taxonomic studies of the genus Notholca

The genus Notholca has been subjected to taxonomic analysis, using cluster analysis and ordination by principal coordinates analysis, based on 67 phenetic characters. All analyses converge on essentially identical groupings, but fail to inject new hypotheses to remedy the confusing and overlapping taxonomy of the genus. This shortcoming is ascribed to the incompleteness of the character set which currently lacks biochemical and genetic parameters. We suggest to invalidate the subspecies' of N. striata into a single species and consider the pros and cons combining N. haueri and N. latistyla.     

Cladistic and phenetic analyses of relationships among Fusarium spp. in Dongtan wetland by morphology and isozymes

Variations of 12 morphological characters and 78 isozymic bands among 78 isolates of five Fusarium spp. from Dongtan wetland were described and analysed with cladistic parsimony and phenetic UPGMA methods. Hierarchical cluster analysis of 12 morphological characters grouped 78 strains into five defined species with a high overlap between isolates. Hierarchical cluster analysis of isozyme patterns showed a higher degree of relationship among five Fusarium spp., in which Fusarium nivale, Fusarium semitectum and Fusarium oxysporum clustered as one group, and F. semitectum was closer to F. nivale than to F. oxysporum; Fusarium graminearum and Fusarium moniliforme formed one group and showed clearly distinct from the first group. Groups of individual isolates indicated by a plot of principal component analysis were consistent with these findings. The comparison of two different data sets revealed that isozyme patterns showed higher variations between species and among individual isolates than morphological characters. Parsimony analysis of morphological characters yielded unresolved cladograms. Parsimony analysis of isozymes as presence/absence characters revealed the same five species in general as the results indicated by phenetic analysis, differing in the relative position of species in subclusters.     

The genus Poa in Patagonia (Argentine): a phenetic analysis of species of Poa subgenus Poa

Fifty-eight quantitative and qualitative exomorphological characters were recorded on 48 herbarium specimens belonging to rhizomatous species belonging to the genus Poa. These were treated as OTUs and analysed, together with the data from caespitose species treated in a previous paper, using cluster analysis, principal component analyses and stepwise discriminant analyses. The following hypotheses are proposed and discussed. (1) There is no evidence supporting the hypothesis that growth habit characterizes supraspecific entities. (2) P. trivialis, P. secunda, P. subenervis and probably P. compressa seem to be well defined species; those remaining are not discriminated through phenetic analysis. (3) There are no phenetic gaps between the rhizomatous species included in the P. oligeria—P. yaganica-P. chrysantha complex and the caespitose P. hachadoensis it is not clear that this single character supports its segregation. (4) The obscurity of the pattern of the species related to P. pratensis-P. nemoralis is probably explained by the capability of P. pratensis to introgress with taxonomically distant species and by the possibility of seasonal intraindividual variation of some characters. (5) The geographical origin of some species postulated as introduced seems to be doubtful.     

20种山茶科植物的叶表皮微形态研究

为解决一些山茶科(Theaceae)的分类学问题,该研究在光学显微镜下对山茶科2亚科6属共20种植物的13种叶表皮微形态特征进行了观察,并利用聚类分析和主成分分析对这些特征进行分析,为山茶科的科学分类提供参考资料。结果表明:(1)山茶科20种植物的13种叶表皮微形态特征能够区分种间差异和分类等级,显示了比较全面的分类价值。(2)基于微形态特征的聚类分析和主成分分析结果显示,20个种分为2个大类群以及10个分支,很好地区分了山茶亚科(Theoideae)与厚皮香亚科(Ternstroemoideae),并将大部分分类地位相近的物种归类到一起,较好地反映了物种之间的亲缘关系。(3)该研究结果支持将小黄花茶组(Sect.Luteoflora)作为独立的一个组;支持将重庆山茶(Camellia chungkingensis Chang)从瘤果茶组(Sect.Tuberculata Chang Tax.)中分离;支持将山茶亚科与厚皮香亚科划分为两个较大类群,认为将厚皮香亚科并入五列木科(Pentaphylacaceae)的观点还有待更多实验证据的支持。     

国产泽泻属的数量分类研究──兼论世界泽泻属种间的表征关系

基于形态学、解剖学、花粉形态和地理分布等证据,应用聚类分析、排序以及空间自相关分析等方法,探讨国产泽泻属４种植物以及世界泽泻属９种植物的表征关系。在此基础上选择和和评价了相对重要的分类性状。     

A QUANTITATIVE STUDY OF VARIATION IN THE CHENOPODIUM ATROVIRENS-DESICCATUM-PRATERICOLA COMPLEX

Multivariate analyses were applied to 96 populations (OTUs) of plants, traditionally referred to Chenopodium atrovirens, C. desiccatum, and C. pratericola, in an attempt to evaluate the numerous and often contradictory taxonomic treatments of plants in this complex. The study consisted of two major parts. The first involved the use of cluster and principal components analyses using 14 morphological characters on the entire set of 96 OTUs to search for phenetically distinct groupings; these analyses were conducted without knowledge of traditional taxonomic designations of individual OTUs. Three reasonably well-defined groups emerged from these preliminary analyses. When traditional taxonomic designations were applied to member OTUs of each group, one group was composed primarily of C. atrovirens, another of C. pratericola and the third of C. desiccatum. The second part of the study utilized canonical analysis to: 1) confirm the integrity of the phenetic groups, 2) to classify OTUs difficult to identify to species using traditional methods, and 3) to provide an evaluation of characters important in the separation of these groups. This analysis confirmed the integrity of the groups and provided a classification to species of nearly all of the otherwise difficult OTUs. In addition, canonical analysis demonstrated that a combination of characters was important in the separation of the phenetic groups.