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1.
P. CUBAS H. TAHIRI C. PARDO 《Botanical journal of the Linnean Society. Linnean Society of London》2001,135(1):43-50
Karyological information on Cytisus species indicates at least two chromosome numbers for most of the taxa. This instability is, a striking karyological feature of Cytisus . Chromosome numbers of taxa in Sect. Spartopsis and Sect. Alburnoides, both well represented in Morocco and the Iberian Peninsula, are presented here. We provide the first data on chromosome numbers for the Moroccan taxa: C. grandiflorus subsp. barbarus , and subsp. haplophyllus (n = 23, 2 n = 46) , C. maurus (2 n = 48), C. megalanthus ( n = 23), C. arboreus subsp. arboreus , subsp. baeticus , and subsp. catalaunicus (2 n = 50), C. valdesii ( n = 23 ). New populations from the Iberian Peninsula have been counted: C. grandiflorus subsp. grandiflorus (2 n = 46), C. scoparius subsp. scoparius ( n = 23) , C. striatus subsp. eriocarpus ( n = 23, 2 n = 46), C. multiflorus (n = 23), C. oromediterraneus ( n = 23, 24). Our data confirm the instability of the chromosome number in Cytisus . The presence of B chromosomes in C. valdesii and C. megalanthus , as well in other species, is discussed in relation to this instability and previous data. We suggest that instability of the chromosome number within a taxon, and even in the same population, may be related to the breakage of A chromosomes and the appearance of B chromosomes. 相似文献
2.
SONIA BERNARDOS FRANCISCO AMICH FRANCISCA GALLEGO 《Botanical journal of the Linnean Society. Linnean Society of London》2003,142(4):395-406
Karyological information on Iberian Ophrys species is very limited. This paper provides the haploid and diploid chromosome numbers of 11 taxa of sect. Pseudophrys and sect. Ophrys , both of which are well represented in the Iberian Peninsula, and two taxa from Tunisia. The first data on chromosome numbers for O. vasconica (2 n = 72, 74), O. ficalhoana (2 n = 36), O. picta (2 n = 36), O. sphegifera ( n = 18, 2 n = 36, 38) and O. passionis (2 n = 36) are also presented, confirming the stability of the chromosome number in Ophrys . In addition, populations of the group O. omegaifera ( O. dyris and O. vasconica ), together with tetraploidy, pentaploidy and the existence of aneuploid phenomena, are reported for the first time in Iberia. The basic diploid number is always 2 n = 36. The karyotypes of several species were analysed. Evolutionary trends in Ophrys chromosomes are discussed. Taxonomic and phytogeographical details are provided on several species or groups of species from Iberia. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003 , 142 , 395−406. 相似文献
3.
AHMET SAHIN YASAR KIRAN TURAN ARABACI ISMAIL TURKOGLU 《Botanical journal of the Linnean Society. Linnean Society of London》2006,151(4):573-580
The chromosome number and morphology of eight species belonging to the section Santolinoideae of the genus Achillea L. (Asteraceae) were investigated using karyological techniques. The species studied were Achillea cucullata (Hausskn.) Bornm., A. vermicularis Trin., A. monocephala Boiss. & Bal., A. boissieri (Hausskn.) Bornm., A. santolina L., A. gypsicola Hub.-Mor., A. goniocephala Boiss. & Bal., and A. spinulifolia Fenzl ex Boiss. In these species, the chromosome numbers were 2 n = 18 in A. vermicularis , A. monocephala , and A. boissieri , 2 n = 18A + 1B in A. spinulifolia , 2 n = 36 in A. cucullata and A. santolina , and 2 n = 54 in A. gypsicola and A. goniocephala . All of the chromosomes had median point (M), median region (m), or submedian (sm) centromeres. An increase in asymmetry was not observed in the karyotypes of the species. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 573–580. 相似文献
4.
P. CUBAS C. PARDO 《Botanical journal of the Linnean Society. Linnean Society of London》1997,125(3):229-243
The two subspecies of Ulex europaeus L. (subsp. europaeus and subsp. latebracteatus) are easily differentiated by the shape and size of their bracteoles, and by their chromosome number. However, in the north-west of the Iberian Peninsula, the areas of both subspecies are not clearly delimited, the shape of the bracteoles is intermediate and the width is close to the diagnostic limit. Thus, allocation of some specimens to either subspecies is diffcult. Recendy, a controversy has arisen concerning the intrapopulational uniformity of the chromosome number in U. europaeus from west France and north Spain, and the usefulness of ploidy level and chromosome number as clear-cut indicators of the two subspecies. Thus, the merits of recognizing the subspecies as independent are re-analysed here. Our results for north-west Spain show that the chromosome number is uniform and stable within populations and is clearly related to the morphological characters. Correlation and discriminant analyses show that bracteoles and stomata sizes are highly correlated and are good predictors of ploidy level. Furthermore, the results support the maintenance of two subspecies in U. europaeus , which can be delimited by a combination of morphological characters, chromosome number and geographical distribution. 相似文献
5.
Although it is generally accepted that the tribe Genisteae has rather homogeneous pollen, we have found considerable variation in pollen size and morphology in Cytisus and related genera (Argyrocytisus and Chamaecytisus), which match taxonomic groups defined on morphological grounds. The results of Principal Component Analysis of pollen characteristics show the following: Cytisus Sect. Alburnoides is well-delimited, with the smallest pollen grains and the simplest pattern in the tectum, fossulate-perforate to perforate; No separation of C. villosus (Sect. Cytisus) from Sect. Alburnoides is observed; Cytisus Sect. Spartopsis, with the largest pollen grains and reticulate to reticulate-fossulate ornamentation, forms an isolated group; C. fontanesii (Sect. Heterocytisus) stands apart from other Cytisus species by its homogeneous ornamentation and the perforate instead of psilate-punctate margo. Thus, the pollen data supports its transfer to the separated genus Chronanthos; Pollen ornamentation and morphology also support the separation of Argyrocytisus battandieri and Chamaecytisus mollis from Cytisus. 相似文献
6.
Karyological studies of some orophyte taxa of the genus Ranunculus L.from the Iberian Peninsula 总被引:1,自引:0,他引:1
J.C. DIOSDADO J. PASTOR 《Botanical journal of the Linnean Society. Linnean Society of London》1993,111(1):23-35
The somatic chromosome number and detailed chromosome morphology have been studied in populations of seven species of Ranunculus, namely Ranunculus alpestris L., R.glacialis L., R. Thora L., R.seguieri Vill., R. Aconitifolius L., R.platanifolius L. And R. Acetosellifolius Boiss., from the Iberian Peninsula. Diploid levels have been found for these species in the samples studied. From the karyological data (karyograms, idiograms and asymmetry) relationships between these taxa are discussed. 相似文献
7.
8.
FRANCISCO AMICH JUAN A. DEVESA SONIA BERNARDOS 《Botanical journal of the Linnean Society. Linnean Society of London》2004,144(3):351-364
A revision of the three endemic Iberian species of Succisella G. Beck ( S. carvalhoana , S. microcephala and S. andreae-molinae ), based on herbarium studies, SEM photographs and field observations, is presented utilizing morphological, palynological, karyological, biogeographical and ecological characters. The distribution of the species in the Iberian Peninsula is shown in a grid map. Full synonymy is given for all taxa. © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 351–364. 相似文献
9.
The chromosome number and morphology in eight species of the sections Ptarmica (Mill.) W. D. J. Koch, Anthemoideae (DC.) Heimerl,
Arthrolepis Boiss., Santolinoideae (DC.) Heimerl and Achillea of the genus Achillea L. (Asteraceae) were investigated using karyological techniques. Sample plants and seeds of A. biserrata M. Bieb., A. fraasii var. troiana Aschers. & Heimerl, A. multifida (DC.) Boiss., A. brachyphylla Boiss. & Hausskn., A. pseudaleppica Hub.-Mor., A. cretica L., A. latiloba Ledeb. ex Nordm., and A. kotschyi Boiss. subsp. kotschyi) were collected from natural habitats in 2003 and 2004. The chromosome number found in seven species was 2n = 18, while only A. kotschyi had 2n = 36. All chromosomes had median point (M), median region (m), and submedian (sm) centromers. In addition, only A. biserrata species had one subterminal (st) chromosome. An increase in asymmetry was not observed in the karyotypes of the species studied.
None of the studied species had any B chromosomes. 相似文献
10.
Torres J.A. Valle F. Pinto C. García-Fuentes A. Salazar C. Cano E. 《Plant Ecology》2002,160(2):207-223
Arbutus unedo L. communities in the southern part of the Iberian Peninsula (Spain and Portugal) were studied, highlighting the differences regarding their floristic composition, biological diversity and plant dynamics according to the dominant geological substratum. Firstly, this type of formation on the little-known decarbonated calcareous substrata was analysed using classification techniques. Later, they were compared to the remaining phytocoenoses in the southern part of the Iberian Peninsula using an ordination analysis. As a result, a new suballiance is proposed together with two plant associations, which will enable us to characterize the strawberry tree groves growing on carbonated substrata and those already proposed for siliceous substrata are confirmed. 相似文献
11.
MANUEL B. CRESPO 《Botanical journal of the Linnean Society. Linnean Society of London》1992,109(3):369-376
CRESPO, MB., 1992. A new species of Vella L. (Brassicaceae) from the south-eastern part of the Iberian Peninsula . Vella lucenlina is described from the coastal, low, dry areas of Alicante Province (south-eastern Spain). This plant is a spineless shrub, woody at the base, with narrowly linear, entire leaves, and an acute tongue-shaped stylar part of the fruit. Affinities and differences with the other taxa in the genus are discussed, and ecological data and conservation proposals are reported. 相似文献
12.
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
13.
SIMONE DE PÁDUA TEIXEIRA ELIANA REGINA FORNI-MARTINS NEUSA TARODA RANGA 《Botanical journal of the Linnean Society. Linnean Society of London》2002,138(4):461-471
Microsporogenesis, chromosome number, meiotic behaviour and meiotic index were investigated in Dahlstedtia pinnata and D . pentaphylla , two legume species occurring largely in Brazil, in order to ascertain whether the pollen could limit fertilization events. Archesporial cells originate primary sporogenous and anther wall precursor cells, the tapetum is uniseriate, uninucleate and glandular. Tetrads are tetrahedric or decussate, and cytokinesis is of the simultaneous type. Mature pollen grains are tricolpate and bicellular. No abnormalities in microsporogenesis were found. In both species the chromosome number is n = 11, a number not reported previously. The base number for Dahlstedtia is also 11, because cytological observations include both species of Dahlstedtia . D. pentaphylla has a higher meiotic index and lower individual variation values, and it is considered meiotically stable. Its pollen grains do not limit fertilization. D. pinnata has a lower meiotic index, and the pollen is one of the factors which limit fertilization. Furthermore, D. pinnata has numerous adventitious shoots, which suggest that vegetative propagation is important in its reproductive process. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 138 , 461–471. 相似文献
14.
J. A. MEJÍAS B. VALDÉS 《Botanical journal of the Linnean Society. Linnean Society of London》1988,98(1):61-69
MEJÍAS, J. A. & VALDÉS, B., 1988. Karyologiepl studies in Sonchus section Madtimi (Asteraceae) from the Iberian Peninmula. Karyological data support the distinction of S. aquatilis Pourret and S. maritimus L. at the specific level. Karyological data and hybridization experiments support the idea that S. × novocaslcllanus Cirujano has been produced by the hybridization of S. crassifolius Pourret ex Willd. and S. maritimus L. 相似文献
15.
JIANQUAN LIU SHANGWU LIU TINGNONG HO ANMIN LU 《Botanical journal of the Linnean Society. Linnean Society of London》2001,135(2):107-112
Twenty-two populations of seven species of Cremanthodium from high altitude regions of western China were observed karyologically. C. ellisii, C. microglossum, C. brunneo-pilosum, C. stenoglossum, C. discoideum and C. lineare all had the same chromosome number of 2 n = 58 whereas C. humile had 2 n = 60. All chromosome numbers of these species are documented here for the first time. The basic number of x = 30 is new for this genus. The karyotypes of all species belong to 2A type according to Stebbins' asymmetry classification of karyotypes. Two basic chromosome numbers, x = 30 and x = 29 in Cremanthodium , correspond exactly to two branching patterns in this genus, sympodial versus monopodial. The systematic and taxonomic statuses of the sympodial species need further study. The karyomorphological data provide no support to the sectional subdivision in Cremanthodium . 相似文献
16.
Pleguezuelos JM Santos X Brito JC Parellada X Llorente GA Fahd S 《Zoology (Jena, Germany)》2007,110(1):9-19
Eurosiberian vipers have been considered model organisms, and studies on their reproductive ecology have afforded much of the current knowledge concerning viviparity in snakes. However, such studies are biased towards northern species and there is little information on Mediterranean species and/or populations. The reproductive ecology of Vipera latastei in the Iberian Peninsula was studied by analysing a large sample of specimens from collections, to better understand the conservation status of this Mediterranean viper. Males and females matured at small and similar body sizes (240 and 265 mm snout-vent length, respectively) and reproductive cycles in both sexes were seasonal. Spermatogenesis peaked in August, vitellogenesis developed in spring and the timing of the mating period was puzzling, with populations mating in autumn, spring, or in both seasons. The most striking finding was that adult females reproduced triennially on average. Lataste's viper is currently in continuous decline in the IP, and most of its populations are isolated in Mediterranean mountains. We hypothesize that prey scarcity and the brevity of the activity period in mountain habitats diminishes the ability of vipers to recover over the short term the energy expended in reproduction. The species needs 2 years for the acquisition and storage of energy ("capital breeder"), and a third year for the expenditure of this energy (in vitellogenesis and embryogenesis), a year during which females feed consistently ("income breeder"). Thus, this viper combines both strategies to supply the reproductive energy cost. Current decline in population and distribution, together with a poor capacity to renew populations, renders Lataste's viper vulnerable to environmental stochasticity. 相似文献
17.
Jürgen Kriwet 《Geobios》2005,38(1):99
The first record of the bowfin order Amiiformes in the Late Jurassic of Portugal is reported. The single specimen comes from the Guimarota coal mine near Leiria in the Lusitanian basin. Here, Kimmeridgian strata that yielded abundant teeth, spines, and scales of selachians and actinopterygians are exposed below ground. The specimen described herein is the only disarticulated fish remain from this locality. It consists of jaw elements, parts of the palatoquadrate and opercular apparatus, an element of the postorbital series and some additional postcranial parts. The systematic position of the new specimen is discussed. The combination of characters allows assignment to the Amioidea rather than to other amiiform groups. Therefore, the specimen constitutes the first undoubted record of an amioid in the Late Jurassic of the Iberian Peninsula and contributes to the knowledge of Late Jurassic amiiform distribution patterns. 相似文献
18.
VICENTA DE LA FUENTE LUIS MARÍA FERRERO EMMA ORTÚÑEZ 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):385-398
Chromosome numbers have been counted in 102 populations belonging to 34 taxa of Festuca L. section Festuca from the Iberian Peninsula. Four of these taxa have been counted for the first time and another three for the first time from the Iberian Peninsula. Furthermore, the levels of ploidy for another three taxa have been obtained for new populations within their distribution area, and for another 18 taxa the ploidy levels have been confirmed. Five levels of ploidy have been established for this section: diploid, tetraploid, hexaploid, octoploid and decaploid. There are 17 diploid taxa, eight tetraploid, three octoploid, two octoploid and one decaploid. The three remaining taxa represent polyploid complexes (one tetra-hexa-octoploid and two hexa-octoploids). 相似文献
19.
A general review is presented of the Carboniferous floral records in the Iberian Peninsula in the context of the geological history and distribution of the different basins. Mississippian floras are found in Sierra Morena, where major strike-slip faults brought in terranes of diverse provenance. Lower Pennsylvanian floras are represented in the Peñarroya-Belmez-Espiel (Córdoba) and Villanueva del Río y Minas (Sevilla) coalfields of SW Spain (also strike-slip controlled), at La Camocha, near Gijón (Asturias), and in other parts of northern Spain. Middle Pennsylvanian is represented near Oporto, but more completely in the Central Asturian Coalfield, as well as other, more limited localities in NW Spain and the Pyrenees. Upper Pennsylvanian (Stephanian Stage-Cantabrian to Stephanian B substages) floras are splendidly represented in NW Spain. Uppermost Pennsylvanian (Stephanian C-Autunian) floras are present in the strike-slip controlled Douro and Buçaco basins of North Portugal, the Pyrenees, Central Spain (Ciudad Real, Guadalajara, Zaragoza), and SW Spain (Guadalcanal and Valdeviar in Sevilla province).A complete succession of megafloral zones is presented. This includes a new Annularia spicata Zone at the top of the Pennsylvanian (equivalent to middle to upper Autunian which has been often attributed to the Lower Permian). The information is summarised in charts compiled from a selection of the most significant species. A number of floral elements are illustrated including the zonal indices. Brief taxonomic comments are provided in the Appendix. 相似文献
20.
ELIANA REGINA FORNI-MARTINS NEUSA DINIZ da CRUZ 《Botanical journal of the Linnean Society. Linnean Society of London》1996,122(2):163-170
Darlington's recombination indices were calculated for eight species of Erythina by adding the mean chiasma frequency and the haploid chromosome number of each species. The recombination indices distinguished subgenus Erythraster (two species with greater mean chiasma frequency) from subgenera Micropteryx and Eythrina. This discrimination corroborates literature data on pollen morphology. It was not possible to separate groups at sectional level using recombination index. The recombination indices were also compared with data on breeding system and pollinators, available in literature, to investigate Grant's hypothesis on the occurrence of compensatory mechanisms in the regulation of recombination in plants. The data on breeding systems in Eythrina are very incomplete and it was not possible to correlate values of recombination indices with autogamy or allogamy. Species visited by hummingbirds showed lower recombination indices than species visited by other kind of pollinators. 相似文献