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1.
Results obtained by comparison of similarity of seed protein spectra of 15 species of the genusAllium (in 22 samples) by means of immunochemical methods more or less correspond to the contemporary division of this genus. Species belonging to the sectionCepa (according to Vvedenskiy) andPhyllodolon have very similar spectra, which suggests that they either should be allocated to one sectionCepa or to two subsections (Cepa andPhyllodolon). Species belonging to the subgenusRhizirideum considerably differ in seed proteins. The investigated species of the subgenusMelanocrommyum show the most distinct spectrum of all the other analyzed representatives, less marked differences were found in the case of the representatives of the subgenusAllium.  相似文献   

2.
Mixed stands of eucalypts were examined on several sites in south-eastern Tasmania. Species from the subgenus Monocalyptus (E. puchella and E. obliqua) became dominant over species from the subgenus Symphyomyrtus (E. viminalis and E. globulus) as the age of the stand increased. In glasshouse trials, Symphyomyrtus species were initially at an advantage since they were more opportunistic than Monocalyptus species owing to their more rapid and even germination and higher initial growth rates. In addition, the Monocalyptus species E. pulchella showed a greater tendency to regenerate vegetatively than the Symphyomyrtus species E. viminalis and E. ovata.  相似文献   

3.
In this study, internal transcribed spacer (ITS) regions within the nuclear ribosomal DNA of KoreanIlex were analyzed in order to investigate any molecular evidence thatI. × wandoensis could serve as a putative hybrid betweenI. cornuta andI. integra. We also sought to clearly identify taxonomic relationships and problems caused by consecutive external morphological characters among taxa in the genus. We sequenced 20 clones fromI. × wandoensis and found these individuals displayed intra-genomic polymorphisms within ITS regions. The analysis of the clones clearly demonstrated the presence of discrete sequences from bothI. cornuta andI. integra, thereby confirmingI. × wandoensis is a species that was formed by crossingI. cornuta andI. integra. Lastly, the subgenusIlex, which contains the evergreen species, failed to form a monophyletic group in a strict consensus tree that was prepared based upon ITS regions.I. crenata var.microphylla in the subgenus KoreaIlex, which has presented taxonomic problems previously, formed an independent clade within the consensus tree, thereby showing distinction fromI. crenata.) Genetic discontinuity ofI. macropoda andI. Macropoda for.pseudo-macropoda individuals couldn't be confirmed.  相似文献   

4.
Flavonoid compounds from 36 of the 38 known taxa of the genusArceuthobium (dwarf mistletoes) were examined. The flavonoid chemistry of the genus is rather uniform, all taxa producing 3-O-glycosides of the flavonols quercetin and myricetin. No infraspecific chemical variation was encountered, and in those instances where subspecific taxa are recognized, their chemistry was uniform. At the subgeneric level, members of subgenusArceuthobium synthesize primarily glucosides, whereas galactosides are more common in subgenusVaginata. In two of the four Old World species of subgenusArceuthobium (A. juniperi- procerae andA. oxycedri) only myricetin 3-O-glucoside was detected. There are no absolute flavonoid differences between subgenera, sections, or series. On the other hand, flavonoids are useful in several instances at the species level. In several cases, chemical data lend support to the recognition of species which in the past have been considered doubtfully distinct on the basis of morphology.  相似文献   

5.
Noel H. Holmgren 《Brittonia》1976,28(2):195-208
Castilleja subgenusCastilleja in the northern half of Mexico consists of nine species, which are treated here. The subgenus is characterized by a conspicuously colored calyx that is much more deeply cleft in front (abaxially) than in back (adaxially).Castilleja rhizomata,C. linifolia,C. mcvaughii, andC. pterocaulon are described as new, and are illustrated and mapped. The first three are compared toC. patriotica and C.tenuiflora, their closest relatives in the Tenuiflorae group, and the fourth is compared toC. ortegae, with which it constitutes the Ortegae group.Castilleja roei andC. tenuifolia of the Epichroma group are included in order to complete the census of subgenusCastilleja as encountered in the region of the new species. A key to the nine species of subgenusCastilleja from the northern half of Mexico is provided.  相似文献   

6.
7.
Three DNA probes isolated from three species ofReithrodontomys (R. montanus, R. megalotis, R. fulvescens) were used to examine within and among species variation in the chromosomal location of satellite DNA and constitutive heterochromatin. These probes hybridized to the centromeric regions on all chromosomes in six species of the subgenusReithrodontomys. Additionally, nearly all extra-centromeric C-band positive regions (with the exception of some heterochromatic material on the X and Y) hybridized to these probes. Within the subgenusReithrodontomys both the chromosomal distribution and organization of satellite DNA has changed throughout evolution. The evolutionary transition has been from a totally centromeric position inR. fulvescens to centromeric and non-centromeric regions in other species that have undergone extensive chromosomal rearrangements from the primitive karyotype for peromyscine rodents. In addition, the monomer repeat of the satellite sequence differs betweenR. fulvescens (monomer defined by PstI) and the remaining species in the subgenusReithrodontomys (monomer defined by EcoRI). These results suggest at least two amplification events for this satellite DNA sequence. Models and mechanisms concerned with the homogenization and spread of satellite sequences in complex genomes are evaluated in light of theReithrodontomys data. From a phlyogenetic standpoint, the satellite sequences composing heterochromatic regions were restricted to the subgenusReithrodontomys, which supports morphological differences used to recognize two subgenera,Reithrodontomys andAporodon. Probes failed to hybridize to any part of the karyotype ofR. mexicanus (subgenusAporodon) or to seven species from other closely related genera (Baiomys, Neotoma, Nyctomys, Ochrotomys, Onychomys, Peromyscus, Xenomys), some of which are considered as potential sister taxa forReithrodontomys.  相似文献   

8.
The wood anatomy of the monogeneric South American family of epiparasites, Misodendraceae, contains numerous peculiarities. In the four species of the subgenusAngelopogon the cambium is virtually inactive in ray areas. In three of those species, a second ring of fascicular areas (“bundles”) forms in the pith only well after the initiation of the outer ring. Fibers occur in fascicular areas in paired strands (sheathed by crystalliferous parenchyma), as the background tissue, or may be absent, depending on the species; rays consist wholly of fibers or are composed of thin-walled cells, depending on the species. In the subgenusMisodendron (seven species), the cambium is active in fascicular areas and interfascicular areas equally; it contributes fibers to potential ray areas and to fascicular areas. If occurrence of these fibers is a criterion, the subgenusMisodendron may be considered rayless (except forM. gayanum, in which fibers occur only in rays). Growth rings are present in all species. Vessel elements are extremely short and narrow, numerous per mm2, and pores are markedly grouped; all these are highly xeromorphic features appropriate to a parasite in an extreme climatic zone. In subgenusAngelopogon, lateral wall pitting of vessels consists of laterally much-widened pits, an appearance falsely resembling helical bands of primary xylem vessels. In subgenusMisodendron, pits on vessels are alternate or scalariformlike. The difference in vessel pitting between the two subgenera may relate to wood parenchymatization. Perforation plates are simple. Pits have wide apertures inM. angulatum andM. recurvum. Pith is sclerenchymatous in subgenusMisodendron but composed of thin-walled cells in which vessel strands occur in subgenusAngelopogon. Because of the numerous specific characteristics which correspond to the taxonomic system for the family, a key to species based on wood anatomy is given. New names must be employed for both subgenera for nomenclatural reasons; thus the combinationM. subgenusAngelopogon (=M. subgenusEumyzodendron) is coined. Wood anatomy of Misodendraceae is similar to that ofPsittacanthus and other Loranthaceae, disregarding the unique features found inMisodendron.  相似文献   

9.
Lopholejeunea subgenusPteryganthus is described as new based upon the Mauritian plantL. sphaerophora (Lehm. & Lindenb.) Steph.Lopholejeunea utriculata Steph. from Madagascar is included as well.Lopholejeunea sinuata (Mitt.) Steph. is reduced to synonymy withL. sphaerophora. The two species of subgenusPteryganthus are compared withL. herzogiana Verd. andL. pullei Verd., two Malaysian species, with superficially similar lobule construction, but not of thePteryanthus type.  相似文献   

10.
Phylogenetic analysis of the plastid (chloroplast) DNA matK gene of Zosteraceae species was undertaken. A molecular phylogenetic tree based on matK sequence data showed the monophyly of Heterozostera tasmanica and subgenus Zosterella and did not support the separation of Heterozostera from the genus Zostera. The tree based on matK supported the monophyly of the subgenus Zostera, and showed that Zosteraceae consist of three main groups: Phyllospadix, which is clearly defined by being dioecious; the subgenus Zosterella and Heterozostera; and the subgenus Zostera. Character-state reconstruction of chromosome number and geographic distribution for our molecular phylogenetic tree showed that 2n=12 is a plesiomorphic character for Zostera and Heterozostera, that the chromosome number was doubled or tripled in two lineages, and that the initial speciation of Zostera and Heterozostera occurred in the Northern Hemisphere. The matK tree showed the close affinity of Z. noltii and Z. japonica, which have disjunct distributions. Zostera marina, which is the only widely distributed species in the subgenus Zostera, also occurring in the northern Atlantic, was shown to be embedded within other subgenus Zostera species.  相似文献   

11.
The ITS-Is of 24 accessions belong to 10 species of subgenusGlycine, and 2 species of subgenusSoja of genusGlycine were amplified, cloned and sequenced. According to the homology of the sequences, the phylogeny of the 24 accessions were reconstructed. The reconstructed dendrogram showed that there were some divergent genomic types found in the previously classified species, such asG. tomentella, G. canescens andG. tabacina, and they might be some cryptic species by morphologic analysis.  相似文献   

12.
The extent of nuclear single-copy DNA divergence between Muntiacus reevesi and Muntiacus muntjak vaginalis (Cervidae), a species pair showing extreme karyotype differences but striking morphological similarity, is 2%, as judged from the thermal stability of interspecific DNA-DNA hybrids. A comparison of the total nuclear DNA reassociation kinetics of the two species indicates a reduction of lowly repetitive sequences in M. m. vaginalis.  相似文献   

13.
Chromosome numbers and karyotypes ofSonchus oleraceus (n=16, 2n=32),S. asper (n=9, 2n=18 for subsp.asper and subsp.glaucescens, andS. microcephalus (n=15, 2n=30) are studied; for the first time their idiograms are given. Karyotypes mainly comprise small chromosomes with a degree of asymmetry 2B inS. oleraceus andS. microcephalus and 2A or 2A-2B inS. asper. No karyological differences can be pointed out betweenS. asper subspecies. Data presented support the amphiploid character ofS. oleraceus, and the origin ofS. microcephalus through a dysploid process involving the former taxon. In Iberian representatives of the genus, diagrams of karyotype asymmetry indices show a cluster grouping for species, with the detached exceptions ofS. maritimus andS. crassifolius, which spontaneously hybridize in central Spain. A review of available karyological data shows that in the evolution of the genusSonchus s.l. and relatives, the basic chromosome number x=9 has generally been maintained. Dysploidy is restricted to the seriesS. bourgeaui (n=8) —S. tenerrimus (n=7) andS. oleraceus (n=16) —S. microcephalus (n=15), evolutionarily related and included in the present subgenusSonchus. Polyploidy has been detected in a total of nine taxa ofSonchus and in the generaEmbergeria, Kirkianella, andDendroseris, being more common in peripheral regions of the distribution area of the group. Five diversification centers are proposed for the whole group, of which the Western Mediterranean area, including the Iberian Peninsula, is related to diversification of the present subgenusSonchus.  相似文献   

14.
A synopsis of the species ofAcalypha subgenusLinostachys known from Colombia is presented. Further, three new species,A. inaequilatera, A. chocoana, andA. castroviejoi, are described and illustrated, and several species are reduced to synonymy. A key is provided to the Colombian species of this subgenus.  相似文献   

15.
The molecular phylogeny of 36 specimens of JapaneseAmanita species was studied based on nucleotide sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. The phylogenetic tree obtained supported the traditional classification systems of Bas (1969) and Singer (1986), which are based on morphological characters, in the division of the genusAmanita is divided into subgeneraAmanita andLepidella by the amyloidity of basidiospores. However, at section-level, we suggest that subgenusAmanita should be divided into three sections (Amanita, Vaginatae, andCaesareae). Our results also showed the necessity to modify the taxonomic treatments at section-level in the subgenusLepidella. It appears that the establishment ofA. muscaria andA. pantherina from a common ancestral species might be a very recent event, or these might be lower taxa of same species. As for three subspecies ofA. hemibapha and three varieties ofA. vaginata, it is necessary to grade up their taxonomical ranks from subspecies/variety to species. A new combination,A. javanica, is proposed forA. hemibapha subsp.javanica.  相似文献   

16.
Aechmea itapoana is a new, conspicuous and distinct species from the coastal sand dune scrub of N.E. Brazil. Its possible relationships within subgenusChevaliera, toA. multiflora andA. rodriguesia are discussed.  相似文献   

17.
The chromosomal localization and genomic organization of three cloned repetitive DNA fragments (viz., H-76, H-61, and H-19) isolated from theAedes albopictus genome have been examined inAe. albopictus and six otherAedes species:Ae. aegypti, Ae. seatoi, Ae. flavopictus, Ae. polynesiensis, Ae. alcasidi andAe. katherinensis. The results fromin situ and Southern hybridization analyses show that the sequences homologous to cloned repetitive DNA fragments are dispersed throughout the genome in each species. The sequences homologous to these cloned repetitive DNA fragments are also found inHaemagogus equinus, Tripteroides bambusa andAnopheles quadrimaculatus and are dispersed in their genomes. Data indicate divergence in the amount and the structural organization of sequences homologous to these cloned fragments among mosquito species.  相似文献   

18.
19.
Thirty species and one variety of Symplocos (Symplocaceae), including all taxa distributed in Japan, were phylogenetically analyzed with DNA sequence data. The evolution of morphological characters is discussed on the basis of the phylogenetic relationships obtained. All species were Asian, except one, S. austromexicana, from Mexico. The nuclear ribosomal internal transcribed spacer (ITS) region and two intergenic spacer regions, between trnL and trnF, and between trnH and psbA of chloroplast DNA were used. The topologies of trees obtained from ITS and the chloroplast intergenic spacers are largely congruent. S. sonoharae, the representative of the subgenus Symplocos in Asia, was sister to all other species. The position of the American species, S. austromexicana, which also belongs to the subgenus Symplocos, was not well resolved. The phylogenetic tree based on combined sequence data largely supports the monophyletic origin of the infrageneric sections proposed earlier. However, the phylogenetic relationship between them is not well resolved, probably due to rapid diversification. The section Palura, a deciduous group, is well defined in the DNA analysis, suggesting its independent status in the genus Symplocos. In spite of their morphological divergence, the three endemic species of the Bonin Islands are monophyletic. The occurrence of curved seeds seems to be homoplastic, scattered over the phylogenetic tree without showing a particular infrageneric relationship.  相似文献   

20.
Barbara Ertter 《Brittonia》1980,32(1):70-102
The genusOxytheca of western North America and temperate South America consists of seven species which are keyed, described, discussed, illustrated, and mapped. They are divided among sect.Oxytheca, sect.Acanthoscyphus stat. & comb. nov., and sect.Neoxytheca sect. nov.Oxytheca dendroidea subsp.chilensis is given as a new combination, whileO. parishii var.cienegensis andO. parishii var.goodmaniana are described as new. The history and relationships of the genus are discussed. It is retained as distinct fromEriogonum and is thought to have arisen from the larger genus nearE. spergulinum, E. parishii, andE. apiculatum in subgenusGanysma. Cytological data indicatedn= 20.  相似文献   

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