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1.
Chromosome banding techniques (Giemsa and fluorochrome staining) were used to investigate Ornithogalum umbellatum L., O. angustifolium Bor. and 11 related taxa. Nine different basic Q-banding patterns, referred to as genomes, could be recognised. These patterns are indicated by capitals (A–E, P–S). Six of the nine basic genome types can be subdivided into different subtypes. The B genome was found in the two bulbilliferous species, i.e. O. umbellatum and O. angustifolium. It occurs in a number of combinations together with the A, C, D and E genomes. Genome combinations of these five basic types were found in seven species. Six of them share morphological characteristics. These species are: O. monticolum Jord. & Fourr., O. baeticum Boiss., O. angustifolium, O. refractum, Kit., O. umbellatum and O. algeriense Jord. & Fourr. A seventh species, O. platyphyllum Boiss., in which the E genome occurs, can be regarded as an intermediate between this complex and the O. montanum group. Each species is treated extensively; its morphology, geographical distribution, chromosome number and banding patterns are discussed separately. A model of the probable course of the evolution in this complex during the last two glaciation periods is described. In this model attention is paid to ecological differentiation, migration leading to the present distribution patterns, hybridization followed by polyploidization and to fixation, which may be the result of chromosomal rearrangements that prevent regular meiosis. Some cytotypes, formerly regarded as O. umbellatum, are now classified in other species. A second polyploid complex in which these species occur, is probably more widely distributed in south-eastern Europe than is generally thought at present. The species O. exscapum Ten., O. nivale Boiss., O. comosum L., O. collinum Guss. and O. gussonei Ten. p.p. are components of this complex. The delimitation of this complex as a whole and the relationship between its diploid and polyploid components have still to be clarified.  相似文献   

2.
Evolutionary relationships and infra- and interspecific variability within the species ofTulipa sect.Eriostemones Boissier were studied. Measurements of 35 morphological characters were used for principal component and canonical variate analyses. Crossing experiments and chromosome counts were carried out. Two axes of morphological variation were encountered within the principal component plot. Variation of subsect.Biflores was traced along one axis, the species of subsect.Australes as well asSaxatiles were found along the other axis. The nomenclature of names of subsect.Biflores was considered on the basis of their geography, specific morphological characteristics and polyploidy. Conspecificity of names of all species was tested based on both morphology and crossability.  相似文献   

3.
The following taxa are represented in East Africa (Kenya, Tanzania, Uganda): Ornithogalum donaldsonii (Rendle) Greenway (2n=20), O. gracillimum R. E. Fries, O. tenuifolium Delaroche ssp. sordidum (Bak.) Stedje comb. nov. (2n=16), and O. tenuifolium Delaroche ssp. robustum Stedje ssp. nov. (2n = 12).  相似文献   

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Abstract Adenophora is an extremely variable genus, and its taxonomy is very controversial. Of the genus, Adenophora potaninii complex, including A. potaninii, A. bockiana, A. wawreana, A. lobophylla, A. biformifolia, A. polydentata, and A. wawreana var. lanceifolia, is a typical group with different taxonomical treatments due to high level of morphological diversity. We carried out extensive biosystematic studies based on population sampling, transplantation experiments and offspring tests, cluster analysis, and a crossing experiment. The results reveal four main findings. (i) Leaf forms of the A. potaninii complex were extremely polymorphic; the leaf form of A. potaninii and A. bockiana, and that of A. wawreana and A. biformifolia could be found, respectively, on a single population or among the offsprings of a single plant. (ii) Cluster analysis and a crossing experiment indicated that A. bockiana and A. polydentata could not be separated from A. potaninii, nor A. biformifolia from A. wawreana. (iii) Adenophora potaninii and A. wawreana were gradational in morphology and their compatibility value was slightly reduced compared to that within each entity. (iv) Adenophora lobophylla was distinct from the other members of the complex in shape and size of corolla, relative length of style, and shape of capsule. This species was incompatible reproductively with the other members of the complex, but partly compatible with A. stenanthina, a species in another section. Therefore, we recognized only one species with two subspecies in the complex, A. potaninii subsp. potaninii and subsp. wawreana, moved A. lobophylla out of the complex, and reduced all the other names as new synonyms.  相似文献   

8.
Adenophora is an extremely variable genus,and its taxonomy is very controversial.Of the genus,Adenophora potaninii complex,including A.potaninii,A.bockiana,A.wawreana,A.lobophylla,A.biformifolia,A,polydentata,and A.wawreana var.lanceifolia,is a typical group with different taxonomical treatments due to high level of morphological diversity.We carried out extensive biosystematic studies based on population sampling,transplantation experiments and offspring tests,cluster analysis,and a crossing experiment.The results reveal four main findings.(i) Leaf forms of the A.potaninii complex were extremely polymorphic; the leaf form of A.potaninii and A.bockiana,and that ofA.wawreana and A.biformifolia could be found,respectively,on a single population or among the offsprings of a single plant.(ii) Cluster analysis and a crossing experiment indicated that A.bockiana and A.polydentata could not be separated from A.potaninii,nor d.biformifolia from A.wawreana.(iii) Adenophora potaninii and A.wawreana were gradational in morphology and their compatibility value was slightly reduced compared to that within each entity.(iv) Adenophora lobophylla was distinct from the other members of the complex in shape and size of corolla,relative length of style,and shape of capsule.This species was incompatible reproductively with the other members of the complex,but partly compatible with A.stenanthina,a species in another section.Therefore,we recognized only one species with two subspecies in the complex,A.potaninii subsp.potaninii and subsp,wawreana,moved A.lobophylla out of the complex,and reduced all the other names as new synonyms.  相似文献   

9.
Meiotic behaviors and reproductive modes of Japanese Isoetes were studied. The hexaploid (2n = 66) and the octaploid (2n = 88) of I. japonica consistently formed 33 and 44 bivalents, respectively, at diakinesis and/or metaphase I in both micro- and megaspore mother cells. The tetraploid (2n = 44) of I. sinensis formed 22 bivalents and its hexaploid made 33 bivalents in both types of spore mother cells. At diakinesis and/or metaphase I of microspore mother cells in I. asiatica with 2n = 22, 11 bivalents were detected. Because behaviors of meiosis in all cytotypes mentioned above were quite regular and plants yielded normal-appearing spores, they should reproduce sexually. Aneuploids of I. japonica with 2n = 87 formed 43 bivalents and one univalent, and I. sinensis with 2n = 65 formed 32 bivalents and one univalent in microspore mother cells. Meiosis of both cytotypes was almost regular and yielded microspores of normal appearance. In the heptaploid (2n = 77) of I. japonica, a configuration of 22 bivalents and 33 univalents was detected in micro- and megaspore mother cells, and various irregularities were observed throughout the meiotic divisions. Therefore, the genomic formula of the heptaploid is symbolized as AABBCDE, and the heptaploid is a sterile F, hybrid between the hexaploid (AABBCC) and the octaploid (AABBDDEE) of I. japonica. Since diploid and even-numbered polyploids regularly formed bivalents and odd-numbered ones displayed irregularities, allopolyploidy should act as a significant speciation mechanism in this genus.  相似文献   

10.
Populations of the genus Philaenus were collected during the last 12 years at several places in Greece ranging in altitude from sea level to 2000 m. Within some of these populations the species P. spumarius (Linnaeus, 1758), which is widely distributed in Greece, and the Mediterranean species P. signatus (Melichar, 1896) occurred together. These two species can be easily distinguished by the size of the adults, and more precisely by internal genital structures. Surprisingly, some mountainous populations of P. spumarius also contained a new species. Externally the new species closely resembled P. spumarius , but careful examination of the male genitalia provided clear identification characteristics. The new species comprised one bisexual common colour morph similar to populi of P. spumarius and P. signatus and two rare unisexual morphs which are lacking both in P. spumarius and P. signatus. The new species occurred only at altitudes above 1200 m on Eryngium spp. (Umbelliferae) between June and August.  相似文献   

11.
Qualitative and quantitative characteristics of mega- and microspores from all the cytotypes of JapaneseIsoetes are described based on the voucher specimens whose chromosome numbers were known. InI. japonica, the hexaploid possessed reticulate megaspores and levigate microspores, while the octaploid and the heptaploid had echinate microspores. Mega- and microspores of the hexaploid and the octaploid were of normal appearance, while those of the heptaploid displayed polymorphism. The tetraploid and the hexaploid ofI. sinensis resembled each other, since they both possessed cristate megaspores and echinate microspores. Echinate megaspores and levigate microspores characterized the diploidI. asiatica. The spore size was largely variable within each cytotype, while the size of the megaspores varied more than that of the microspores. The microspore length was closely correlated with polyploid level. InI. sinensis, the mean microspore length of the tetraploid was 27.6 μm while that of the hexaploid was 31.9 μm, hence these two cytotypes were easily distinguishable. In the hexaploidI. japonica, variations in mega-and microspore size displayed geoclinal variation showing a positive correlation (r=0.43–0.55) with the longitude and the latitude of the populations. A palynological key for cytotypes is presented.  相似文献   

12.
The genus Cousinia Cass. (Family Asteraceae) with about 600–700 species is distributed in central and western Asia. Iran has more than 200 Cousinia species that grow in mountainous areas. Cousinia is not monophyletic and with the genus Arctium, comprise the Arctium-Cousinia complex. The Cousinia species are distributed in 70 sections. The species relationship in the sect. Cousinia is not known, moreover, in few cases, inter-specific hybrids and intermediate forms are recognized. Therefore, we undertook a detailed morphological, micro-morphological and molecular (Cp-DNA and ISSRs) study of the section Cousinia with the following objectives: 1- to delimitate the species, 2- to identify potential intermediate forms, 3- to investigate the species inter-relationship. The present study revealed that combination of morphological, micro-morphological and ISSR data can delimit the species. We did not encounter any intermediate forms throughout the studied area. AMOVA and STRUCTURE analysis revealed that the species of this section are genetically differentiated but have some degree of shared common alleles. Reticulation analysis by T-REX also showed some degree of gene flow for Cp-DNA. This low degree of genetic and morphological variability in Cousinia, can help the species to cope with environmental variability they face.  相似文献   

13.
Based on a combined dataset of plastid DNA sequences (atpB‐rbcL, trnG, trnL‐trnL‐trnF, trnK 5' intron and matK) from 60 individuals, we conducted parsimony and likelihood analyses to clarify the phylogenetic relationships among the six species and three varieties that are commonly recognised in Heloniopsis, in addition to the related genera Ypsilandra and Helonias, using Chamaelirium and Chionographis as an outgroup. According to the single most parsimonious tree, which was identical to the maximum‐likelihood tree in topology, Helonias, Ypsilandra and Heloniopsis are all monophyletic with 100% bootstrap support (BS). In Heloniopsis, there are two highly supported clades (BS 94–97%): a clade of Korean species and a clade of Japanese and Taiwanese species. The latter clade comprised the following four subclades (BS 99–100%): 1) H. orientalis var. orientalis, 2) H. orientalis var. breviscapa and var. flavida, 3) H. kawanoi and 4) H. leucantha and H. umbellata. Because subclades 1 and 2 did not form a monophyletic group, and do show clear morphological differences – including nectary position, nectary‐sac structure and leaf margin undulation – they should be distinguished at the species level: H. orientalis for subclade 1 and H. breviscapa for subclade 2. In subclade 2, neither var. breviscapa nor var. flavida was monophyletic; instead, var. breviscapa plus var. flavida (thick‐leaved entity) was monophyletic (BS 62–63%) and var. flavida (thin‐leaved entity) was monophyletic (BS 86–87%). As var. breviscapa and var. flavida (thick‐leaved entity) share basally ± pinkish wide tepals and dark‐coloured thick leaves, in contrast to var. flavida (thin‐leaved entity), which has completely white narrow tepals and light‐coloured thin leaves, the two varieties should may be kept distinct after the merge of var. flavida (thick‐leaved entity) with var. breviscapa.  相似文献   

14.
Adenophora potaninii Korsh.complex is a morphologically variable group including six species.As shown in many species in the genus Adenophora,the variability of many morphological characters in the complex under investigation is amazingly great,which brings difficulties in the delimitation and indentification of taxa.In the present study,six populations representing five species in the complex were systematically sampled to investigate the pattern of morphological variation within population and to detect the genetic basis of the variation with progeny tests and controlled crosses.The results are as follows: Great morphological variation within population is found (Fig.1),including characters such as leaf shape,teeth number and size of leaf margins,teeth number of calyx lobes,and indumentum on the surface of stems and leaves,which were previously considered as diagnotic.Systematic sampling and statistical analysis show that the differences in the above characters exhibit continuous patterns of variation within population (Fig.1,2),though they are highly correlated (Table 2).From progeny testing and crossing between two contrast types of individuals (oblong,dentate and pubescent leaves vs.narrow,entire and glabrous leaves)it is evident that those characters show continuous variability in segregating progenies (Fig.3,4)and appear to be influenced by large numbers of loci with individually slight effects.Since most wild populations were highly heterozygous for those characters,the individuals in one extreme of variation can produce their variable offsprings including individuals similar to those in the other extreme (Fig. 3). This is also true for the indumentum density on stems and teeth number of calyx lobes. In this complex, A. biformifolia Y. Z. Zhao, A. bockiana Diels and A. polydentata P.F. Tu et G. J. Xu were described exclusively based on leaf shapes, teeth number of leaf margins and calyx lobes, teeth size of leaf margins, and indumentum on the surface of stemsand leaves. It is demonstrated, however, that the variation of those characters is of a quantitative nature and show no discontinuities. As a result, genetic analysis of diagnostic characters along with their sympatric distribution and same habitats, strongly suggest that A.biformifolia as well as A. bockiana and A. polydentata are actually the extreme individuals within A. wawreana and A. potaninii respectively and should not be recognized as taxa at any taxonomic level.  相似文献   

15.
Aspidistra is a genus mainly found in eastern Asia, with its distribution and differentiation center in Guangxi of China. In the present paper, all the taxa hitherto recorded in China are taxonomically and phytogeographically revised. As a result, 47 species are recognized, of which 45 are endemic to China and four are new to science, i. e. A. ebianensis K. Y. Lang et Z. Y. Zhu, A. fenghuangensis K. Y. Lang, A. oblongifolia F. T. Wang et K. Y. Lang and A. fosciaria G. Z. Li, A key to all species is provided and all the speci-mens examined are cited.  相似文献   

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17.
An account is given of the morphology and taxonomy of the African genus Ornithoglossum Salisb. The genus belongs to the Liliaceae–Wurmbeoideae, a phytochemi–cally distinct taxon sometimes treated as a separate family, the Colchicaceae. Ornithoglossum belongs to the tribe Iphigenieae, which is here amended to include the former tribe Glorioseae. Within the genus Ornithoglossum 8 species are here recognized, 3 of which are new, viz. O. parviflorum B. Nord., O. vulgare B. Nord. and O. gracile B. Nord. Two varieties of O. parviflorum are recognized. O. zeyheri (Baker) B. Nord. is a new combination. The chromosome number 2n = 24 is recorded for four species. The genus is believed to have originated in formerly arid regions of tropical Africa. Because of a climatic change, an increase in humidity, a south– and southwestward migration took place, followed by speciation in response to factors in the new environment. Sympatric speciation may have been promoted by the development of differences in flowering times and by specialization to different pollinators. The evolution of the nectary region of the tepals is particularly illuminating, and taxonomically useful. The proposed taxonomy is further supported by ultrastructural features of the seeds and pollen grains.  相似文献   

18.
中国蜘蛛抱蛋属植物的分类和植物地理的研究   总被引:12,自引:1,他引:12  
蜘蛛抱蛋属植物主要产于亚洲东部,中国的广西是其现代的分布中心和分化中心。通过对从其 分类和植物地理方面的研究和修订,确认此属中国产有47种,其中45种为中国所特有,4个种为新种。文中列有中国产全部种的分种检索表和全部标本引证。  相似文献   

19.
During a survey on the presence of species of the genusAspergillus in the air of the city of Barcelona (Spain), the following species were identified:Aspergillus flavus Link,A. niger van Tieghem,A. fumigatus Fresenius,A. clavatus Desmazières,A. terreus Thorn,A. chevalieri (Mang.) Thomet Church,A. niveus Bloch, emend. Thomet Church,A. ochraceus Wilhelm,A. versicolor (Vuillemin) Tiraboschi, andA. amstelodami (Mang.) Churchet Thom.  相似文献   

20.
Abstract

A karyological analysis carried out in Scilla hyacinthoides L. and Scilla amoena L. on material collected in the Botanical Garden of Cagliari (Sardinia), has shown the presence of heterozygous karyotypes in the two species. The chromosome number of S. hyacinthoides was found to be 2n = 20, while the chromosome number of S. amoena was 2n = 12, in accordance with the data found in the literature. Both the observed karyotypes show clear structural alterations, especially evident in one pair of clearly heteromorphic chromosomes. The analysis of the karyotypes seem to exclude a hybrid origin of the material examined and it is probable that such karyotypes may be the result of various structural re-arrangements, still evolving and aiming at a cytogenetic stabilization of the genus Scilla.  相似文献   

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