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1.
One new species ofSerjania (S. erythrocaulis) belonging to theS. paradoxa group ofSerjania sect.Eurycoccus is described and illustrated bringing the total number of species in this group to eight. A second new species,Serjania divaricocca, belonging to sect.Serjania is also described and illustrated.
Resumen  Una especie neuva deSerjania (S. erythrocaulis) perteneciente al grupoS. paradoxa de la secciónEurycoccus es descrita e ilustrada. Con esta especie, el numero total de especies conocidas para este grupo aumenta a ocho. Una segunda nueva especie,Serjania divaricocca, perteneciente a la secciónSerjania es también descrita e ilustrada.
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2.
Shape variations in the dentition and the cranium were analyzed for sevenSaguinus forms of the hairy-face tamarin by applying the factor analysis method. The results obtained for the dental and cranial measurements were almost consistent with each other. The magnitude of the difference in shape factors between theS. nigricollis group and theS. midas group is appreciably larger than that between the former group and theS. mystax group. If the ancestral geographic centre of origin is postulated as being within the region which is inhabited by the livingS. nigricollis group, the morphological distances between any pairs of groups correlate well with the geographic distances between them. Concerning the dental and cranial morphologies, the physical changes in the three species group probably took place in two directions; that is, from theS. nigricollis group to theS. mystax group, and from theS. nigricollis group to theS. midas group. The forms belonging to each species group are more closely related to each other, with the exception ofS. imperator in theS. mystax group. The uniqueness ofS. imperator was clearly demonstrated by factor analysis and distance analysis. In theS. mystax group, although still hypothetical,S. imperator may have been related only through the basic ancestral stock toS. labiatus andS. mystax.  相似文献   

3.
J. Mark Egger 《Brittonia》2002,54(3):190-195
Castilleja hidalgensis is described from several collections from xeric limestone sites in central Hidalgo, Mexico. The new species belongs to a small complex of poorly known and uncommon species within sect.Euchroma, sharing important characteristics withC. macrostigma, the first-described taxon in this assemblage. The new species appears to be rare and highly restricted both geographically and ecologically. A key to the species of theC. macrostigma group is provided.  相似文献   

4.
Scilla persica and 5 species of the so-calledS. hohenackeri group, namely,S. furseorum, S. puschkinioides, S. vvedenskyi, S. hohenackeri, andS. greilhuberi, have been investigated embryologically with special reference to embryo sac and endosperm development.Polygonum-type embryo sac development was stated inS. puschkinioides andS. greilhuberi. 8-nucleate, normally structured embryo sacs, which could not be specified further due to sparse availability of the material, were stated inS. furseorum, S. vvedenskyi, andS. hohenackeri. InS. persica the embryo sac develops according to the bisporicAllium-type. In most species endosperm development was stated to be nuclear, exceptS. hohenackeri, where the type could not be specified. Other traits of possible taxonomic significance are the number of layers in the outer integument, which is mostly 4, or 5–6 inS. furseorum, and the occurrence of polyploid versus haploid and early degenerating antipodal nuclei, the latter occurring only inS. persica andS. furseorum. These embryological characters may be useful for assessing taxonomic relationship of the present species with other allied groups withinScilla, in particular, theS. siberica alliance,S. messeniaca, and theS. bifolia alliance. TheAllium-type embryo sac, which occurs inS. persica, is also characteristic for theS. siberica alliance, and may be a common derived character. Lack of antipodal polyploidization, as characteristic forS. persica andS. furseorum, occurs also in theS. siberica alliance, and is perhaps another common derived trait indicating phylogenetic relationship. Nuclear endosperm development is more frequent in spring-flowering squills than helobial development, which has previously been stated inS. messeniaca, some species of theS. siberica alliance, and inS. litardierei. While helobial endosperm may be primitive forHyacinthaceae in general, it may, by reversal, also occur as a derived character, at least in some species of theS. siberica alliance.  相似文献   

5.
O. A. Sæther 《Aquatic Ecology》1992,26(2-4):191-196
Heterotrissocladius boltoni sp.n. from Ohio, U.S.A., is described in both sexes and all stages. The species belongs in themarcidus group and is found in temporary streams and pools  相似文献   

6.
Phagnalon rechingeri spec. nova from S Baluchestan (Iran) is described as a species new to science and illustrated; its relationships to other species of the genus, in particular to thePh. woodii group from S Arabia, are discussed.Dedicated to Hofrat Univ.-Prof. DrK. H. Rechinger on the occasion of his 80th birthday.  相似文献   

7.
A new species in theEpidendrum difforme complex is described and illustrated,E. oldemanii. Closely related toE. amapense, E. oldemanii is distinguished by the absence of a midlobe to the labellum.  相似文献   

8.
A new species ofTachia,T. longipes, is described and illustrated. It is distinct from the other species ofTachia not only in its leaf and stem morphology but also in its characteristic pollen. A revised key to the neotropical species ofTachia is also provided. Studies for theFlora of the Guianas. No. 87.  相似文献   

9.
10.
Resolution of species delimitations in theRhynchospora globosa complex has revealed three species new to science from South America:R. bracteovillosa, R. leucoloma, andR. melanocarpa. Each species is described and illustrated and its geographical distribution discussed.  相似文献   

11.
Trimble ST  Sagers CL 《Oecologia》2004,138(1):74-82
Carbon and nitrogen stable isotopes were used to examine variation in ant use of plant resources in the Cecropia obtusifolia / Azteca spp. association in Costa Rica. Tissue of ants, host plants and symbiotic pseudococcids were collected along three elevation transects on the Pacific slope of Costa Ricas Cordillera Central, and were analyzed for carbon and nitrogen isotopic composition. Worker carbon and nitrogen signatures were found to vary with elevation and ant colony size, and between Azteca species groups. Ants in the A. constructor species group appear to be opportunistic foragers at low elevations, but rely more heavily on their host plants at high elevations, whereas ants in the A. alfari species group consume a more consistent diet across their distribution. Further, isotope values indicate that both ant species groups acquire more nitrogen from higher trophic levels at low elevation and when ant colonies are small. Provisioning by the host is a substantial ecological cost to the interaction, and it may vary, even in a highly specialized association. Nonetheless, not all specialized interactions are equivalent; where interaction with one ant species group appears conditional upon the environment, the other is not. Differential host use within the Cecropia-Azteca association suggests that the ecological and evolutionary benefits and costs of association may vary among species pairs.  相似文献   

12.
Taxonomy of thePresbytis melalophos group in Sumatera has been based solely on the distinction in the pelage coloration and has been a subject of controversy. In the present study, extensive field observations were undertaken. Three species, i. e.P. melalophos, P. thomasi, andP. femoralis, are recognized in Sumatera based on the cranial morphology, pelage coloration, and vocalization. Subspecies of each species are revised, a new classification is proposed, and a new subspecies,Presbytis melalophos bicolor, is described. A detailed distribution map of species and subspecies is presented. No sympatry occurs between the species. Finally, a cladistic analysis is presented for the three species, based on the cranial characters; the branching sequence is first between theP. melalophos clade and theP. femoralis- P. thomasi clade and second between theP. femoralis clade and theP. thomasi clade.  相似文献   

13.
Examinations of 23 forms ofCallicebus were made to elucidate their phylogenetic relationships based on cranial measurements. Multivariate statistical methods of distance analysis utilizing Q-mode correlation coefficients and principal component analysis were employed. As a result, the following five distinct groups were recognized morphometrically among the 23 species and subspecies: theDonacophilus, Cupreus, Moloch, Personatus, andTorquatus groups. Moreover, the phenetic characters of cranial size, karyotype, pelage coloration, and geographic range were consistent with the results of this group classification. It could be safely concluded therefore that these groups represented phylogenetically independent groups, in view of the fact that the rate of character differentiation was not appreciably different among closely related groups. Of the five groups, thePersonatus andTorquatus groups were respectively considered to maintain a higher peculiarity of character differentiation within theCallicebus phylogeny, since these two groups individually displayed the higher magnitudes of differentiation in both their craniometric shape and some phenetic features. Conversely, the other three groups were considered to be closer to each other in theCallicebus phylogeny.  相似文献   

14.
The DNA sequence structure of 5S DNA units inAcacia species, including representatives from the three subgenera ofAcacia, have been determined. The data was interpreted to suggest that at least three lineages of 5S DNA sequences exist inAcacia and the proposal was made that the lineages be named5S Dna-1, 5S Dna-2, and5S Dna-3. The5S Dna-1 lineage was represented by units fromA. boliviana andA. bidwilli, the5S Dna-2 lineage by units fromA. melanoxylon, A. pycnantha, A. ulicifolia, A. boliviana, A. bidwillii, andA. albida, and the5S Dna-3 lineage by units fromA. bidwillii, A. boliviana, andA. senegal. Based on this interpretation of the sequence data, the Australian species of subg.Phyllodineae grouped together as a cluster, quite separate from the subgeneraAculeiferum andAcacia. As expected from the analyses of morphological characters, the 5S DNA units fromAcacia albida (syn.Faidherbia albida) were quite separate from the otherAcacia spp.  相似文献   

15.
Pelage color and pattern, facial markings, cranial morphology, and vocalization have been studied comparatively in thePresbytis melalophos group in Sumatera. Pelage coloration of fetuses and neonates were described forP. melalophos andP. femoralis. Based on this study, three species —P. thomasi, P. melalophos, andP. femoralis — are recognized. Using field data that have been gathered since 1981, the distribution of these three species has been mapped. The resultant map reveals that no sympatry is known and that rivers form the interspecific boundaries. However, rivers apparently are not barriers to the dispersal of species in this group. Instead, distributions appear to be limited ecologically, by competitive exclusion. Historically, it appears that the ancestral stock initially dispersed throughout this area, then theP. melalophos stock split from theP. thomasi-P. femoralis stock, theP. thomasi stock split from theP. femoralis stock, and, finally, theP. femoralis stock dispersed to eastern Sumatera. It appears unlikely that the centrifugal speciation hypothesis based on the principle of metachromism applies to deployment of theP. melalophos group.  相似文献   

16.
The karyotypes ofElymus dentatus from Kashmir andE. glaucescens from Tierra del Fuego, both carrying genomesS andH, were investigated by C- and N-banding. Both taxa had 2n = 4x = 28. The karyotype ofE. dentatus was symmetrical with large chromosomes. It had 18 metacentric, four submetacentric and six satellited chromosomes. The karyotype ofE. glaucescens resembled that ofE. dentatus, but a satellited chromosome pair was replaced by a morphologically similar, non-satellited pair. The C-banding patterns of both species had from one to five conspicuous and a few inconspicuous bands per chromosome. N-banding differentiated the chromosomes of the constituent genomes by producing bands in theH genome only. TheS genomes of both species were similar with five metacentric and two satellited chromosomes having most conspicuous C-bands at telomeric and distal positions. They resembled theS genome of the genusPseudoroegneria. TheH genomes had four similar metacentric and two submetacentric chromosomes. The seventhH genome chromosome ofE. dentatus was satellited, that ofE. glaucescens nonsatellited, but otherwise morphologically similar. The C-bands were distributed at no preferential positions. TheH genome ofE. dentatus resembles theH genomes of some diploidHordeum taxa.  相似文献   

17.
Four agar media used to isolate aflatoxin producing fungi were compared for utility in isolating fungi in theAspergillus flavus group from agricultural soils collected in 15 fields and four states in the southern United States. The four media wereAspergillus flavus andparasiticus Agar (AFPA, 14), the rose bengal agar described by Bell and Crawford (BCRB; 3), a modified rose bengal agar (M-RB), and Czapek's-Dox Agar supplemented with the antibiotics in BC-RB (CZ-RB). M-RB was the most useful for studying the population biology of this group because it permitted both identification of the greatest number ofA. flavus group strains and growth of the fewest competing fungi. M-RB supported an average of 12% moreA. flavus group colonies than the original rose bengal medium while reducing the number of mucorales colonies and the number of total fungi by 99% and 70%, respectively. M-RB was successfully employed to isolate all three aflatoxin producing species,A. flavus, A. parasiticus andA. nomius, and both the S and L strains ofA. flavus. M-RB is a defined medium without complex nitrogen and carbon sources (e.g. peptone and yeast extract) present in BC-RB. M-RB should be useful for studies on the population biology of theA. flavus group.Abbreviations M-RB Modified Rose Bengal Agar - CZ-RB Czapeks Rose Bengal Agar - BC-RB Bell and Crawford's Rose Bengal Agar - AFPA Aspergillus flavus andparasiticus agar  相似文献   

18.
Circumstantial evidence, mostly morphological and ecological, points to ten different mushroom host species for up to fifteen species of the mycoparasitic genus Squamanita. Here, molecular evidence confirms Cystoderma amianthinum as the host for S. paradoxa, a sporadically occurring and rarely collected mycoparasite with extreme host specificity. This is only the second study to use molecular techniques to reveal or confirm the identity of a cecidiocarp of Squamanita species. Phylogenetic analysis of combined nuclear ribosomal RNA genes suggests the monophyly of Squamanita, Cystoderma, and Phaeolepiota, a clade referred to as the tribe Cystodermateae. If true, S. paradoxa and C. amianthinum would represent a relatively closely related species pair involved in a mycoparasitic symbiosis.  相似文献   

19.
InSaccharomyces cerevisiae the only known role of theCBP2 gene is the excision of the fifth intron of the mitochondrialcyt b gene (bI5). We have cloned theCBP2 gene fromSaccharomyces douglasii (a close relative ofS. cerevisiae). A comparison of theS. douglasii andS. cerevisiae sequences shows that there are 14% nucleotide substitutions in the coding region, with transitions being three times more frequent than transversions. At the protein level sequence identity is 87%. We have demonstrated that theS. douglasii CBP2 gene is essential for respiratory growth in the presence of a wild-typeS. douglasii mitochondrial genome, but not in the presence of an intronlessS. cerevisiae mitochondrial genome. Also theS. douglasii andS. cerevisiae CBP2 genes are completely interchangeable, even though the intron bI5 is absent from theS. douglasii mitochondrial genome.  相似文献   

20.
Genomic relationships of 13 tetraploid species within the AsiaticElymus parviglumis group containing the SY genomes were assessed by analysing chromosome pairing at metaphase I of the parental species and their interspecific hybrids. Two major genomic subgroups among the tetraploids were identified from the cluster analysis of the averaged c-values, namely, theE. caucasicus subgroup (two species) and theE. parviglumis subgroup (11 species). The genomic affinity of theElymus species is associated with the interspecific geographic distance.After October 1, 1993  相似文献   

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