余甘子天然居群果实形态变异研究

为了从数量性状上分析余甘子天然居群果实表型性状在居群间和居群内的变异,在云南省选取了6个余甘子天然居群,分别测量了其8个果实表型性状并作比较分析。结果显示:(1)余甘子果实表型性状在居群间和居群内存在着较丰富的变异,8个果实性状在居群间的F值为20.17～35.21,部分差异达到显著水平;居群内的F值为1.27～3.07,差异均达到极显著水平。(2)余甘子居群内的平均表型变异接近90%,是余甘子果实表型遗传变异的主要来源。(3)余甘子表型性状的变化与生态和地理因子显著相关;主成分分析结果显示,单果重、果实横径、外果皮重、果核宽、果核重等5个表型性状指标是反映滇西北余甘子果实表型差异的主要因素。     

小叶锦鸡儿天然居群叶形态性状变异研究

为揭示小叶锦鸡儿(Caragana microphylla)天然居群叶形态性状的变异规律及其生态适应性特征,该研究以10个小叶锦鸡儿天然居群为对象,通过多重比较、巢式方差分析、相关性分析、聚类分析和主成分分析等方法,对7个叶形态性状进行分析。结果表明：(1)小叶锦鸡儿叶形态性状在居群内和居群间均存在极显著差异(P < 0.01),平均变异系数为10.13%,不同性状的变异幅度为6.23%~12.78%;平均叶形态性状的表型分化系数为43.62%,居群内变异(30.09%)大于居群间变异(24.91%),说明居群内是其叶形态性状变异的主要来源。(2)相关性分析表明,环境因子对小叶锦鸡儿的叶形态性状变异有很大的影响,在地理空间上主要呈现出沿海拔梯度的变异模式;主成分分析的结果显示,小叶宽、叶柄宽和叶柄长对小叶锦鸡儿叶形态变异起主导作用;利用欧式距离对小叶锦鸡儿居群进行UPGMA聚类分析结果显示,基于叶形态性状和环境因子可分别将小叶锦鸡儿10个居群分为3类和2类,Mantel检验结果表明,小叶锦鸡儿的叶形态性状变异不存在地理连续性。研究结果为小叶锦鸡儿的适应性进化和开发利用提供了理论依据。     

柠条锦鸡儿不同居群形态变异研究

结合数量统计方法对柠条锦鸡儿12个居群的12项形态特征进行了研究。结果表明：除小叶对数、叶形和荚果长外,其余形态性状在居群内或居群间都表现显著差异;以12个形态性状为基础的聚类分析将所研究的12个居群分为3类;主成分分析结果显示每荚种子、干粒重、托叶长和叶长等4个性状是造成柠条锦鸡儿表型差异的主要因素。     

武陵地区蛇足石杉不同居群形态变异分析

为了从数量上分析蛇足石杉(Huperzia serrata)天然居群表型性状在居群间和居群内的变异,对分布在武陵地区的15个蛇足石杉天然居群的9个表型性状进行了测量和比较分析.结果表明:顶叶长、顶叶宽、顶叶长宽比、茎基径、基叶长、基叶长宽比、株高、节间长在居群间表现显著差异;聚类分析和主成分分析显示,15个居群可分为3类,顶叶长、顶叶长宽比、茎基径、株高、节间长这5个性状是反映表型差异的主要因素.     

福建山樱花天然居群表型变异研究

以闽、赣、粤三省天然分布的福建山樱花(Cerasus campanulata Maxim.)为研究对象,调查了11个居群226个单株的17个表型性状指标,运用变异系数和单因子方差分析研究了居群间和居群内的表型变异;应用相关分析揭示了表型性状间及其与地理、气候因子间的相关性以及表型变异的地理格局;并且运用聚类分析进行了居群分类.结果表明,福建山樱花天然居群内的变异远大于居群间的变异,居群分化较小;花色、花量与经度、纬度间显著或极显著相关,花瓣宽与纬度、海拔显著或极显著相关,花色、花量与年降雨量极显著相关,花量、花瓣宽、开花习性与年日照时数显著相关,花瓣宽与年均温、无霜期显著或极显著相关,存在较明显的地理变异趋势.而居群间马氏距离聚类分析结果与参试居群分布地域性呈现高度一致,二者之间相关显著.     

小毛莨居群分化研究（Ⅰ）——居群内和居群间的形态变异

对小毛莨的3个地点共6个居群的形态变异作了观测,该种的株高、叶形、花瓣数目等性状具有显著的居群内和居群间变异。用31个形态及生境性状作出的聚类分析结果表明,小毛莨巨群遗传分化主要与居群所在生境因素相关,与地理位置之间仅有不显著的相关性。     

小毛茛居群分化研究(Ⅰ)——居群内和居群间的形态变异

对小毛茛的 3个地点共 6个居群的的形态变异作了观测。该种的株高、叶形、花瓣数目等性状具有显著的居群内和居群间变异。用 31个形态及生境性状作出的聚类分析结果表明 :小毛茛居群遗传分化主要与居群所在生境因素相关 ,与地理位置之间仅有不显著的相关性。     

不同居群野生早樱形态变异研究

利用数量分类学手段对福建武夷山和江苏宝华山不同居群野生早樱形态特征进行了比较研究。通过对2大居群24项形态指标的分析,不论是聚类分析还是主成分分析,2大居群的各个个体均归并为2类,自然体现出不同居群野生早樱表型特征的较大差异。主成分分析显示,叶部特征的长度、宽度、叶基夹角等,以及花部特征的花萼筒、花冠幅、花序总梗等是造成不同居群野生早樱表型差异的主要因素,单因素方差分析也印证了这一结论。最后,建议在分类学关系上将福建武夷山野生早樱做为大叶早樱新变种处理。     

半夏种内居群形态变异的模糊聚类分析

在同一栽培条件下,对主要引自长江中下游地区的１５个半夏〔Ｐｉｎｅｌｉａｔｅｒｎａｔａ（Ｔｈｕｎｂ．）Ｂｒｅｉｔ．〕居群的１６个主要形态性状进行模糊聚类分析,在置信水平λ＝０．６７６４时,将１５个居群划分成４个类型：（１）双珠芽类型：主要形态特征为叶柄上均具双珠芽,但叶型和块茎形状变异较小;（２）普通类型：主要形态特征为叶柄上均只着生单珠芽,但叶型和块茎形状变异较大;（３）长茎类型：主要形态特征为叶柄上具单珠芽,但着生位置较低,块茎呈矩圆形;（４）复合类型：主要形态特征为叶柄上具单珠芽,但居群内常有双珠芽个体出现。     

尖叶拟船叶藓居群叶形态变异的初步研究

对东桠特有濒危植物尖叶拟船叶藓4个地点9个居群叶的形态变异进行了初步观测,结果表明,7个形态指标除叶表外,叶的形状、叶细胞形状、叶基部反曲和宽窄程度、叶边缘的分化及齿的类型和数量、叶尖和中肋的相对长度等均存在一定程度的变异,尤其是后三者变异程度较大,在梵净山的4个居群中,随着海拔的上升,叶的宽度递减和长度递增,叶缘齿的数量递减,叶尖和叶中肋的相对长度却以中度海拔的居群较大。     

Phenotypic variations in natural populations of Amygdalus pedunculata

Aims Our objectives were to determine the phenotypic variations, adaption and distribution patterns in seven natural Amygdalus pedunculata populations.Methods We analyzed 14 phenotypic traits from 120 individuals in seven populations of A. pedunculata by variance analysis, correlation analysis, and cluster analysis.Important findings Results showed that there were plentiful phenotypic variation within and among populations. In particular, the phenotypic variation within population was 40.91%, higher than that among populations (35.29%), which indicated that the phenotypic variation within population was the main source of the phenotypic variation in A. pedunculata. Mean differentiation coefficient was 45.90%, and mean coefficient of variation of 14 traits was 15.59%, ranged from 9.39% to 31.98%. Mean annual temperature, latitude, length of frost-free period, longitude and altitude appear to be prominent ecological factors influencing phenotypic traits. Mean annual temperature and length of frost-free period were key indicators to phenotypic of A. pedunculata in different site conditions. According to principal component analysis and unweighted pair-group method with arithmetic means (UPGMA) cluster analysis, the seven populations of A. pedunculata could be divided into two groups. In mountainous region, A. pedunculata’s leaf blade was usually rotund to oblong, fruit nearly spherical shape with shorter fruit stem, stone was usually ovoid to spherical shape. In contrast, in sandy region, leaf blade was long oval to ovate-lanceolate, fruit and stone was usually flat ovoid with longer fruit stem. Our results provide critical information for the resource collection and breeding of this ecologically important species.     

Morphological and Genetic variations in the natural populations of Carinotetraodon travancoricus

Carinotetraodon travancoricus or Malabar puffer fish is an endemic species described from rivers originating from the Western Ghats in South India. This species is captured extensively as an aquarium fish and is having substantial demand in global markets. However, being prone to overfishing and impacts of anthropogenic alterations in its habitats, IUCN has categorized it as a threatened/vulnerable species. Since, knowledge on variability of wild populations could help in their conservation and management, morphometric and genotypic analyses were carried out in natural populations of C. travancoricus inhabiting two geographically separated rivers Pamba and Chalakkudy. Mean values of eleven length parameters measured in 456 males and 439 females inhabiting these rivers revealed significant difference (ANOVA, F = 10.2 p < .001) between sexes and between females inhabiting two rivers. Principal component analysis revealed two factors in males and three factors in females, explained variance of 83.62% and 89.94% in respective sexes. Results of both PCA and discriminant function analysis indicated perceptibly high degree of separation between individuals inhabiting the two rivers. A total of 25 COI sequences were generated from C. travancoricus collected from rivers Pamba (n = 14) and Chalakkudy (n = 11). Sequence alignment revealed considerable base substitutions between samples from both rivers, indicating possibility of population differences. AMOVA analysis also provided significant Fst value (0.622; p-value .00) in support of population difference between individuals of both rivers. Interpopulation genetic distance reached upto 2.50%, high enough to confirm genetic diversity among individuals, revealing perceptible population events within this species. The present results indicated high degree of population difference between C. travancoricus inhabiting geographically separated rivers Pamba and Chalakkudy as evidenced from both morphometric and genotypic analyses.     

塔额盆地野果林不同居群野扁桃土壤种子库及幼苗更新研究

【目的】明确新疆野扁桃(Amygdalus ledebouriana)土壤种子库及幼苗更新特征,探究影响野扁桃种群更新受限因子。【方法】以新疆塔额盆地的野扁桃为研究对象,通过对野外样地调查、土样采集及母株下幼苗数量、级别统计的方法对新疆野扁桃土壤种子库及幼苗更新进行研究。【结果】(1)野扁桃土壤种子库种子平均密度为96.45粒/m2,托里居群完整种子密度最大,裕民居群被啃食种子密度最大,虫蛀种子仅在塔城居群出现;(2)野扁桃种子主要分布在枯枝落叶层,占种子总量的56.29%,S2(0—5 cm)土层占29.07%,S3(5—10 cm)土层占14.65%,土壤种子水平扩散距离与野扁桃所处坡度成正比;(3)调查的野扁桃幼苗中未发现实生苗,Ⅰ级苗占幼苗总数的51.13%,母株基部50 cm内的范围是野扁桃幼苗集中分布区域。【结论】野扁桃土壤种子库分布特征表现为近母株及地表,幼苗更新的特征也表现为近母株分布,自然条件下,被啃食种子、虫蛀种子和生态位缺失是野扁桃实生苗无法萌发,实生更新受限转而进行萌生更新的主要原因。     

Morphological and chemical variations in natural populations of Pituranthos triradiatus in the Negev Desert

Morphochemical variations among six populations of Pituranthos triradiatus have been studied in the Negev Desert, in areas located within an air distance of 80 km, with an aridity gradient from 150 to 50 mm of average annual rainfall. Based on morphological florisitic characters, as well as on the content of furanocoumarins in the shoots of the shrub, five different populations have been observed. Some of the morphological characters which are commonly used for classification in the species level were found useful for the subspecies level, e.g. number of rays per umbell or per umbellet. Others, such as the shape of petals or stylopodium, or petals color, were not efficient. In addition to the commonly used characters, average fruit weight was found useful. Seven different furanocoumarins were found in the examined populations of P. triradiatus. Four of them (isoimperatorin, imperatorin, bergapten and isopimpinellin) were in each of the populations studied. Three other furanocoumarins were found to be specific: cnidilin for the Revivim population; pimpinellin for Zin and isobergapten for the Marzeva and Neqarot populations. In addition to these specific furanocoumarins, the amount of bergapten in the shoots seems to be specific for each population and is suggested to be used as a chemical marker for further screening of chemotype differentiation in R. triradiatus. It is suggested that the differences in the floristic characters, as well as in the content of furanocoumarins are of genetic nature and not an artifact. To better establish this view and to evaluate the efficiency of furanocoumarins content as a chemotaxanomic marker, further work is needed. It is also suggested that levels of isolation among the investigated population account for the differences encountered. No association could be found between different levels of aridity and different levels of furanocoumarin content.     

Morphological polyvariance of ontogeny in natural plant populations]

The main patterns of expression of the morphological polyvariance of plants are discussed: diversity of biomorphs, pathways of ontogeny, and disturbances of morphogenesis. The diversity of biomorphs of tap root plants in different ecological conditions has been analyzed in detail. Promising directions of future studies have been formulated.     

岷江柏天然种群种实表型变异特征

运用巢式方差分析、变异系数、表型分化系数和聚类分析等多种分析方法,研究了11个岷江柏种群的13个种实表型性状在种群内和种群间的变异及其与环境因子间的关系,并对其进行了类群划分.结果表明: 岷江柏种实表型性状在种群间和种群内均存在显著差异,种群内的变异(49.7%)大于种群间的变异(28.6%),种间平均分化系数为43.4%,分化程度相对较大.球果质量的平均变异系数最高(37.2%),其次是单个球果种子质量,球果长的平均变异系数最小(8.0%),是最稳定的种实性状.康定县的表型多样性最丰富,武都县的最小.在岷江柏的研究区内,最热月的平均气温和生长季的水分条件是其种实表型的主要限制因子.依据13个种实表型性状将11个岷江柏天然种群分为2类3亚类,基本上代表了3个流域的种群分布情况.大渡河流域种群种实表型性状最佳,岷江流域最差.     

Seasonal variations in active dispersal of natural populations of Triatoma infestans in rural north-western Argentina

The flight dispersal of Triatoma infestans Klug (Hemiptera: Reduviidae) is one of the main mechanisms determining community re-infestation after control interventions. An empirical model of flight initiation coupled with data from a longitudinal study predicted that the flight dispersal of T. infestans would peak in summer. To test this prediction, longitudinal light trap collections were conducted during 3-8 nights in March (late summer), July (winter) and November (spring) 2003, and in March 2004 in a rural community in north-west Argentina. Following each light-trapping collection date, all peridomestic sites around light traps were inspected to assess the relative abundance and nutritional status of T. infestans at each site. A total of 21 adult and five nymph T. infestans, six Triatoma guasayana Wygodzinsky & Abalos, and nine Triatoma garciabesi Carcavallo et al. were collected in 96 light-trapping nights, whereas 696 T. infestans were collected from the peridomestic sites that surrounded the light traps. The arrival of T. infestans in the light traps occurred in 64% of catch stations and peaked in the summer surveys (10-14 bugs) compared with spring and winter surveys. When winds were < 5 km/h, the arrival of adult T. infestans at the light traps was significantly associated with maximum temperature and relative humidity. This is the first field report of seasonal variations in the flight dispersal activity of T. infestans.     

Morphological variations of Caragana microphylla populations in the Xilingol steppe and their relationship with environmental factors

The morphological variations of branches, leaves, flowers, fruits and seeds of Caragana microphylla and their correlations with environmental factors were analyzed based on five natural populations in the Xilingol steppe, Inner Mongolia, China. Nested variation analysis showed that there were significant differences in all of the 28 morphological characters within and among populations in 16 morphological characters, and the variations within populations were much greater than those among populations in most morphological characters. Cluster analysis showed that the five populations of C. microphylla could be divided into two groups in morphological characters, and there was significant positive correlation between the divergence of morphological characters matrix and geographical distance matrix. Principal component analysis showed that leaflet length, area of a compound leaf, fresh-mass of a compound leaf, and shoot fresh-mass were main morphological characters that varied among C. microphylla populations. Spearman correlation analysis showed that there were significant correlations between some morphological characters and soil factors. Soil N:P ratio, available N content, total N content, organic matter content and soil water content were main factors that were associated with morphological characters of C. microphylla.