Hawkmoth pollination of Bonatea speciosa (Orchidaceae) in a South African coastal forest

Hawkmoths ( Theretra capensis and Hyles lineata livornica ) pollinated the orchid Bonatea speciosa at a forested site along the southern Cape coast of South Africa. The flowers of B. speciosa are strongly evening-scented and hawkmoth activity was confined to a short period of 40 minutes after dusk on each evening of observation. The pollinaria are exceptionally elongated (c. 20 mm in length) and are affixed to the eyes of the hawkmoths. Pollinaria attached to feeding hawkmoths are brushed over the long stigmatic arms which project in front of flowers. The flowers of B. speciosa have a toothlike process at the mouth of the spur which forces moths to enter the flower from either side. As a result, only one of the pollinaria is removed from the flower during a visit. The division of the flower into two functional units by the toothlike process in the spur distinguishes the floral mechanism of B. speciosa from other Habenariinae.     

Nuclear DNA content in Sinningia (Gesneriaceae); intraspecific genome size variation and genome characterization in S. speciosa

The Gesneriaceae (Lamiales) is a family of flowering plants comprising >3000 species of mainly tropical origin, the most familiar of which is the cultivated African violet (Saintpaulia spp.). Species of Gesneriaceae are poorly represented in the lists of taxa sampled for genome size estimation; measurements are available for three species of Ramonda and one each of Haberlea, Saintpaulia, and Streptocarpus, all species of Old World origin. We report here nuclear genome size estimates for 10 species of Sinningia, a neotropical genus largely restricted to Brazil. Flow cytometry of leaf cell nuclei showed that holoploid genome size in Sinningia is very small (approximately two times the size of the Arabidopsis genome), and is small compared to the other six species of Gesneriaceae with genome size estimates. We also documented intraspecific genome size variation of 21%-26% within a group of wild Sinningia speciosa (Lodd.) Hiern collections. In addition, we analyzed 1210 genome survey sequences from S. speciosa to characterize basic features of the nuclear genome such as guanine-cytosine content, types of repetitive elements, numbers of protein-coding sequences, and sequences unique to S. speciosa. We included several other angiosperm species as genome size standards, one of which was the snapdragon (Antirrhinum majus L.; Veronicaceae, Lamiales). Multiple measurements on three accessions indicated that the genome size of A. majus is ~633 × 10? base pairs, which is approximately 40% of the previously published estimate.     

Use of AFLP and RAPD molecular genetic markers and cytogenetic analysis to explore relationships among taxa of the Patagonian Bromus setifolius complex

Bromus setifolius var. pictus (Hook) Skottsb., B. setifolius var. setifolius Presl. and B.setifolius var. brevifolius Ness are three native Patagonian taxa in the section Pnigma Dumort of the genus Bromus L. AFLP and RAPD analysis, in conjunction with genetic distance measurements and statistical techniques, revealed variation within this group and indicated that B. setifolius var. brevifolius was closely related to B. setifolius var. pictus, with both taxa being more distantly related to B. setifolius var. setifolius. Cytogenetic analysis confirmed the chromosomal number of B. setifolius var. pictus (2n = 70) and B. setifolius var. setifolius (2n = 28) and showed for the first time that B. setifolius var. brevifolius had 2n = 70. The combination of molecular genetic and cytogenetic evidence supported a species status for two of the three taxa and suggested hypotheses for the evolutionary origin of these complex taxa. Species status was also indicated for B. setifolius var. setifolius. Based on these findings, we suggest that B. setifolius var. pictus be referred to as B. pictus Hook var. pictus, and B. setifolius var brevifolius as B. pictus Hook var brevifolius. The correlation between AFLP diversity and variation in ecological parameters suggested that this marker system could be used to assess breeding progress and to monitor the domestication of Patagonian Bromus species for agronomic use.     

Molecular characterization of relatedness among colour variants of Asian Arowana (Scleropages formosus)

Morphological identification of fish taxa can sometimes prove difficult because phenotypic variation is either being affected by environmental factors, phenotypic characters are highly conserved or marker selection has been inappropriate. DNA based markers especially neutral mitochondrial DNA (mtDNA) have been used widely in recent times to provide better resolution of systematic relationships among vertebrate taxa. The Asian Arowana (Scleropages formosus) is a high value ornamental fish belonging to the family Osteoglossidae with a number of different colour variants distributed geographically across different locations around Southeast Asia. Systematic relationships among colour variants still remain unresolved. Partial sequences of the Cytochrome B (Cyt B) and DNA barcoding gene, Cytochrome C Oxidase I (COI) were used here to assess genetic relationships among colour variants and as a tool for molecular identification for differentiating among colour variants in this species. Results of the study show that in general, colour pattern shows no relationship with extent of COI or Cyt B mtDNA differentiation and so cannot be used to identify taxa. Partial sequences of the mtDNA genes were sufficient however, to identify S. formosus from a closely related species within the order Osteoglossidae.     

A statistical/computer-graphic technique for assessing variation in tectonically deformed fossils and its application to Cambrian trilobites from Kashmir

Hughes, N. C. & Jell, P. A. 1992 07 15: A stdlislical/compuler-graphic technique for assessing variation in tectonically deformed fossils and its application to Cambrian trilobites from Kashmir.
A combined approach using statistics and computer graphics can help resolve patterns of morphological variation in tectonically deformed fossils. Bivariate analyses and Principal Components Analysis can be used to identify a generalized strain vector in populations of deformed fossils, the identification of which permits discrimination of biological and tectonically induced variation. Results can be used to determine the number of taxa and growth relationships within the population. Statistically resolved taxa can be compared with species described from other areas using computer-aided shape restorations. Application of these techniques to a sample of trilobite cranidia from the Cambrian of Kashmir demonstrates that the variation of characters used to diagnose several genera and species are ontogeny- or deformation-controlled. Seven previously described species of Saukia, Prosaukia, Hundwarella and Anomocare are best considered as a single species, Hundwarella personara . These results suggest a Middle Cambrian age for the fauna, which has affinities with other faunas described from India and northern China. Hundwarella personara shows a pattern of developmental flexibility similar to that seen in other Cambrian trilobites. Morphometrics, computer-aided restoration, deformed fossils, allometry, trilobites, Cambrian, Kashmir, developmental flexibility .     

Cryptic species diversity in a widespread bumble bee complex revealed using mitochondrial DNA RFLPs

Cryptic species diversity is thought to be common within the class Insecta, posing problems for basic ecological and population genetic studies and conservation management. Within the temperate bumble bee (Bombus spp.) fauna, members of the subgenus Bombus sensu stricto are amongst the most abundant and widespread. However, their species diversity is controversial due to the extreme difficulty or inability morphologically to identify the majority of individuals to species. Our character-based phylogenetic analyses of partial CO1 (700 bp) from 39 individuals spread across their sympatric European ranges provided unequivocal support for five taxa (3–22 diagnostic DNA base pair sites per species). Inclusion of 20 Irish specimens to the dataset revealed ≥2.3% sequence divergence between taxa and ≤1.3% within taxa. We developed a PCR-RFLP based method for unequivocally distinguishing amongst the four cryptic European taxa of this subgenus, B. cryptarum, B. lucorum, B. magnus and B. terrestris, and used it to analyse 391 females of the former three species collected across Ireland, all of which could be unambiguously assigned to species. Bombus lucorum was the most widely distributed and abundant of the cryptarum–lucorum–magnus species complex, comprising 56% of individuals, though it was significantly less abundant at higher altitudes (>200 m) whilst B. cryptarum was relatively more abundant at higher altitudes. Bombus magnus was rarely encountered at urban sites. Both B. lucorum and B. terrestris are nowadays reared commercially for pollination and transported globally. Our RFLP approach to identify native fauna can underpin ecological studies of these important cryptic species as well as the impact of commercial bumble bees on them.     

Molecular evolution and diversity in Bacillus anthracis as detected by amplified fragment length polymorphism markers.

Bacillus anthracis causes anthrax and represents one of the most molecularly monomorphic bacteria known. We have used AFLP (amplified fragment length polymorphism) DNA markers to analyze 78 B. anthracis isolates and six related Bacillus species for molecular variation. AFLP markers are extremely sensitive to even small sequence variation, using PCR and high-resolution electrophoresis to examine restriction fragments. Using this approach, we examined ca. 6.3% of the Bacillus genome for length mutations and ca. 0.36% for point mutations. Extensive variation was observed among taxa, and both cladistic and phenetic analyses were used to construct a phylogeny of B. anthracis and its closest relatives. This genome-wide analysis of 357 AFLP characters (polymorphic fragments) indicates that B. cereus and B. thuringiensis are the closest taxa to B. anthracis, with B. mycoides slightly more distant. B. subtilis, B. polymyxa, and B. stearothermophilus shared few AFLP markers with B. anthracis and were used as outgroups to root the analysis. In contrast to the variation among taxa, only rare AFLP marker variation was observed within B. anthracis, which may be the most genetically uniform bacterial species known. However, AFLP markers did establish the presence or absence of the pXO1 and pXO2 plasmids and detected 31 polymorphic chromosomal regions among the 79 B. anthracis isolates. Cluster analysis identified two very distinct genetic lineages among the B. anthracis isolates. The level of variation and its geographic distribution are consistent with a historically recent African origin for this pathogenic organism. Based on AFLP marker similarity, the ongoing anthrax epidemic in Canada and the northern United States is due to a single strain introduction that has remained stable over at least 30 years and a 1,000-mile distribution.     

Wing shape as a potential discriminator of morphologically similar pest taxa within the Bactrocera dorsalis species complex (Diptera: Tephritidae)

Four morphologically cryptic species of the Bactrocera dorsalis fruit fly complex (B. dorsalis s.s., B. papayae, B. carambolae and B. philippinensis) are serious agricultural pests. As they are difficult to diagnose using traditional taxonomic techniques, we examined the potential for geometric morphometric analysis of wing size and shape to discriminate between them. Fifteen wing landmarks generated size and shape data for 245 specimens for subsequent comparisons among three geographically distinct samples of each species. Intraspecific wing size was significantly different within samples of B. carambolae and B. dorsalis s.s. but not within samples of B. papayae or B. philippinensis. Although B. papayae had the smallest wings (average centroid size=6.002 mm±0.061 SE) and B. dorsalis s.s. the largest (6.349 mm±0.066 SE), interspecific wing size comparisons were generally non-informative and incapable of discriminating species. Contrary to the wing size data, canonical variate analysis based on wing shape data discriminated all species with a relatively high degree of accuracy; individuals were correctly reassigned to their respective species on average 93.27% of the time. A single sample group of B. carambolae from locality 'TN Malaysia' was the only sample to be considerably different from its conspecific groups with regards to both wing size and wing shape. This sample was subsequently deemed to have been originally misidentified and likely represents an undescribed species. We demonstrate that geometric morphometric techniques analysing wing shape represent a promising approach for discriminating between morphologically cryptic taxa of the B. dorsalis species complex.     

中国明亮熊蜂复合种的分子鉴定及分布特性

【目的】为了探明中国境内明亮熊蜂复合种Bombus lucorum complex的物种组成及其分布特性。【方法】利用DNA条形码技术对来源于中国境内的明亮熊蜂复合种的223个标本进行了鉴定, 并根据鉴定结果分析了各物种的分布特性。【结果】中国境内明亮熊蜂复合种包括地熊蜂B. terrestris、 隐熊蜂B. cryptarum、 明亮熊蜂B. lucorum和长翅熊蜂B. longipennis。4种熊蜂共获得160条DNA条形码序列, 包含36个单倍型, 其中B. longipennis单倍型最多, 为14个; B. terrestris最少, 为3个。B. terrestris和B. lucorum亲缘关系最远, 其遗传距离为0.077; B. lucorum和B. longipennis亲缘关系最近, 其遗传距离为0.034。系统进化分析（贝叶斯法和最大似然法）表明, 4种熊蜂的分化先后顺序为B. terrestris, B. longipennis, B. lucorum和B. cryptarum。4种熊蜂的分布格局不同, 平均分布海拔高度由高到低的顺序依次为B. longipennis, B. cryptarum, B. lucorum和B. terrestris。B. longipennis发现于高海拔的青藏高原东部及南部地区, 而B. terrestris仅发现于低海拔的新疆西北部边界地带。【结论】本研究探明了中国境内明亮熊蜂复合种的分类地位及其分布特性, 为深入研究该类群的资源保护和农业授粉利用奠定了基础。     

Genetic differentiation among morphological variants of Acacia saligna (Mimosaceae)

This study investigated the pattern of genetic variation in Acacia saligna (Labill.) H.L. Wendl. to facilitate its development as a crop species for dryland salinity management. A. saligna is a morphologically variable species and four main variants are recognized. The genetic structure within A. saligna was investigated in populations across the geographic range of the species using nuclear restriction fragment length polymorphism loci. The analysis identified considerable genetic variation within A. saligna that was genetically structured into three groups. Two of the three groups corresponded to variants recognized in the field study; the third group encompassed the other two variants which, though morphologically different, were not genetically differentiated. The level of genetic differentiation between the groups suggests they may represent different taxa and a taxonomic revision of the species may be required. Identification of different taxa within A. saligna will have implications for the utilization and domestication of the species, as the taxa will need to be evaluated separately to determine their suitability for agroforestry. The high genetic variation between and within groups suggests there is a large genetic base available for breeding improved cultivars.     

Biometrics of exuviae of Cordulegaster boltonii algirica Morton, 1916 (Odonata: Cordulegastridae)

This study provides the first biometrics analysis of exuviae from Moroccan populations of the Ibero-Maghrebian endemic dragonfly Cordulegaster boltonii algirica Morton, 1916 collected in the Rif Mountains. Among the biometric variables that were measured, tibia length was highly correlated with the exuviae body length (BL), and can, therefore, be used to calculate the BL of partially broken exuviae. The head width exhibited the smallest coefficient of variation for both males and females and, therefore, is a valuable measurement that can be used for biometric comparison of different populations. The data presented herein will be used for future comparison with other North African and European populations of C. boltonii algirica.     

The Analysis of Morphological Characters and a Taxonomic Revision on Panzerina anata (L.) Sojak Complex (Labiatae)

Panzerina lanata ( L. ) Sojak complex is distributed on the Mongolia plateau. Twenty-two populations representing six species in the complex: P. lanata, P. alaschanica, P . kansuensis , P . albescens , P. argyracea and P . parviflora , were sampled throughout the range of the complex including 2 provinces and 3 autonomous regions. Extensive studies were carried out by comparison of wild collection and cultivation, and morphological analysis based on character evaluation and multivariate procedures. It is showed that there exists considerable phenotypic plasticity in some morphological characters, especially those of the root, caudex and leaf. However, the characters of flowers, capsules and seeds were less influenced by environments. The character analysis indicates that some characters, which were used to distinguish taxa of the complex, for example the degree of leaf division, the morphology of calyx and so on, are continuous in a wide range in wild populations. Some “species” in the complex described according to the differences in those characters are only extreme individuals within their continuous variation. As a result, the above analysis and their geographical distribution suggest that P. alaschanica , P. kansuensis , P. albescens be actually the extreme individuals within P. lanata. In the same way, P. argyracea is invalid. The principal components analysis of 11 morphological characters on the individuals from 22 populations shows no differences. Thus, this paper considers that characters such as nutlet with or without wart, size of corolla exceeding calyx or not and dry flowers with or without colour, may be used to distinguish taxa of this complex. From the above analysis, it is indicated finally that the six species in this complex are better reduced taxonomically into two species, namely P. lanata (L.) Sojak and P. parviflora (C. Y. Wu et H. W. Li) Y. Z. Zhao, the difference of two species as follow: Nutlet surface smooth; corolla, 2～2.2 cm long; flower white and unchanging after dry .......................................................... Panzerina parviflora Nutlet surface tuberculate; corolla, 2.5～ 4 cm long; flower white, but becoming yel- lowish after dry ....................................................... P. lanata     

Using change-point analysis and weighted averaging approaches to explore the relationships between common benthic diatoms and in-stream environmental variables in mid-atlantic highlands streams,USA

Diatoms are increasingly being used in the bioassessment of aquatic systems. However, autecological information for many common taxa is incomplete. We explored the potential of classification (CT) and regression tree (RT) approaches to identify the hierarchical interaction among water quality variables in predicting the relative abundance of ten common stream diatom taxa in the Mid-Atlantic Highlands ecoregion. RT analysis was also used to identify environmental change points corresponding to major shifts in species abundances. We also used traditional weighted-averaging approaches (WA) to model taxon pH and total phosphorus (TP) optima. RT and WA approaches provided different, yet complementary, information on the complex relationships between common stream diatoms and environmental variables. Both RT and CT highlighted the interaction of stream acidity (pH, acid neutralizing capacity (ANC)), and TP in structuring the stream diatom assemblage. For the RT of taxa, where pH was an important predictor, higher pH predicted higher relative abundances. In contrast, higher TP predicted lower relative abundances for some diatom taxa (e.g., Achnanthidium minutissimum (Kütz.) Czarnecki), while predicting higher relative abundances for other taxa (e.g., Planothidium lanceolatum (Bréb.) Round & Bukht., Gomphonema parvulum (Kütz.) Kütz.). The environmental change point for pH derived from RT analysis was lower than WA optima for all species. We suggest that RT change point analysis can be used to complement traditional WA optima approaches, especially when diatom taxa’s abundances are affected by interactive environmental factors, to provide more refined information on stream diatom environmental preferences. Handling editor: L. Naselli-Flores     

Significance of variation and evaluation of potential characters in three morphologically similar species of <Emphasis Type="Italic">Barleria</Emphasis> sect. <Emphasis Type="Italic">Barleria</Emphasis> (Acanthaceae) in southern Africa

The variation exhibited within three species of Barleria (B. bechuanensis, B. irritans and B. jubata) was studied to establish whether it was discrete or continuous. Morphological characters were examined and recorded in matrices. Cluster analysis was employed to impose a hierarchical non-overlapping association among operational taxonomic units (OTUs) while ordination was used to establish whether the variation was discrete or continuous. Discrete characters were determined from quantitative morphological data using box and whisker plots. Locality information for the OTUs was obtained from herbarium labels and used to generate maps to illustrate geographic distribution of taxa. Cluster analysis and ordination demonstrated that there was discrete variation within Barleria bechuanensis, B. irritans and B. jubata, which each split into two distinct clusters, although box and whisker plots illustrated that many quantitative characters overlapped within and between species. Since clear morphological gaps between clusters are assumed to be indicators of breaks in gene flow, the distinct clusters were recognised at species level.     

Polymorphism in the Aegean "five-loculed" species of the genus Campanula, Section Quinqueloculares (Campanulaceae)

Population variation in species of Campanula Section Quinqueloculares and related taxa has been studied. 19 species and 48 populations from the Aegean region have been sampled. There are few distinct character states available for analysis so that metric variables have been scored. 11 leaf variables and 19 flower variables have been measured in up to 683 plants. Regressions of variables with overall size have been calculated and where significant allometric variation has been detected residual scores have been used as variables. Hierarchical analysis of variance has indicated that a large part of the total variation is found between populations within species rather than within populations. Between the 10 most closely related species there is a considerable overlap in population means of variables. Multivariate analysis also fails to identify distinct species clusters. In particular principal components analysis provides additional evidence of overlap between species. It is suggested that a detailed study of genetic variation within and between species is required in order to establish the presence of any distinct phylogenetic lineages.     

Hybridization in the Daphnia galeata complex: are hybrids locally produced?

Within the species complex of Daphnia galeata,D. cucullata and D. hyalina variouscombinations of hybrids and parental taxa occur inlakes throughout Europe. Since daphnids are cyclicparthenogens and mostly reproduce asexually, hybridpopulations can be maintained by asexual reproductionand without recurrent hybridization events. Therefore,it is possible that hybridization events have beenrare, with range expansion occurring by dispersal ofhybrids.Allozyme data from seven European populations wereused to compare genetic variation within and betweenhybrid and parental taxa. An UPGMA cluster analysis ofgenetic distances showed that D. cucullata × galeatahybrids from different lakes grouped indifferent clusters according to the lake from whichthey were isolated, suggesting multiple hybridizationevents. Clonal diversity within hybrid taxa wascomparable to parental taxa. Furthermore, evidence wasfound for introgression of the Pgi-S allele fromD. cucullata to D. galeata in three lakes.These results indicate that multiple hybridizationevents within this species complex are likely, andthat hybrid taxa can reproduce sexually.     

Habitat and host specificity of trematode metacercariae in fiddler crabs from mangrove habitats in Florida

Fiddler crabs (Uca spp.) are common inhabitants of temperate and tropical coastal communities throughout the world, often occupying specific microenvironments within mangrove and salt marsh habitats. As second intermediate hosts for trematodes, we investigated patterns of host distribution and parasitism for 3 species of sympatric fiddler crabs in mangrove habitats adjacent to the Indian River Lagoon, Florida. Fiddler crab distribution varied among species, with Uca speciosa dominating the low and mid intertidal regions of mangrove banks. This species also exhibited higher prevalence and abundance of Probolocoryphe lanceolata metacercariae compared with Uca rapax, which is relatively more abundant in the high intertidal zone. We conducted a field experiment to test whether U. speciosa was more heavily parasitized by P. lanceolata as a result of its habitat distribution by raising U. speciosa and U. rapax under identical environmental conditions. After exposure to shedding cercariae under the same field conditions, all individuals of U. speciosa became parasitized by P. lanceolata, whereas no U. rapax were parasitized, suggesting that differences in parasitism were driven by host selection.     

Patterns of evolution of mitochondrial cytochrome c oxidase I and II DNA and implications for DNA barcoding

DNA barcoding has focused increasing attention on the use of specific regions of mitochondrial cytochrome c oxidase I and II genes (COI-COII) to diagnose and delimit species. However, our understanding of patterns of molecular evolution within these genes is limited. Here we examine patterns of nucleotide divergence in COI-COII within species and between species pairs of Lepidoptera and Diptera using a sliding window analysis. We found that: (1) locations of maximum divergence within COI-COII were highly variable among taxa surveyed in this study; (2) there was major overlap in divergence within versus between species, including within individual COI-COII profiles; (3) graphical DNA saturation analysis showed variation in percent nucleotide transitions throughout COI-COII and only limited association with levels of DNA divergence. Ultimately, no single optimally informative 600 bp location was found within the 2.3 kb of COI-COII, and the DNA barcoding region was no better than other regions downstream in COI. Consequently, we recommend that researchers should maximize sequence length to increase the probability of sampling regions of high phylogenetic informativeness, and to minimize stochastic variation in estimating total divergence.