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1.
In Iran and the neighbouring regions of Turkey, Iraq, U.S.S.R. and Afghanistan, eight already known species belonging to the subsectionVariegatae Radzhi, occur:V. persica Boiss.,V. armena Boiss.,V. variegata Willd.,V. akhmaganica Kazar.,V. gregaria Boiss. etHeldr.,V. aucheri Jaub. etSpach and the two new species described here,V. rechingeri Chrtková-?ertová andV. afghanica Chrtková-?ertová. The occurrence of most species is restricted to a limited area which may be one of the evolutionary centres of this subsection.  相似文献   

2.
The paper deals with some problems of distribution and variability of the speciesL. angustissimus L.,L. halophilus Boiss. etSprun.,L. laricus Rech. fil.,Aellen etEsfandiari, L.,schimperi Steud.,L. compactus Chrtková-?ertová,L. garcinii DC.  相似文献   

3.
The region of Iran, Iraq, Afghanistan and the neighbouring countries is important for some groups of the speciesLotus L., especially those of the circle ofL. corniculatus L. andL. gebelia Vent. The first group is represented by the speciesL. corniculatus L. with 4 subspecies (3 of which are important for this region), andL. tenuis Waldst. etKit. which here attains the eastern boundary of the continuous area of distribution, and by the eastern speciesL. krylovii Schischk. etSerg. andL. rechingeri Chrtková-?ertová. The second group is represented by the speciesL. gebelia Vent.,L. michauxianus Ser. in DC. andL. libanoticus Boiss. their areas of distribution covering mostly those regions. Most of the species show considerable variability within the species.  相似文献   

4.
我国西部及邻国的鮡属鱼类   总被引:1,自引:2,他引:1  
丁瑞华 《四川动物》2003,22(1):27-28
我国属 (Pareuchiloglanis)是科鱼类中第二大类群 ,至今已知有 1 2种 ,主要分布于我国西部的山区河流中 ,在邻国越南、缅甸和印度也有分布。类资源较丰富 ,是产区群众的食用鱼之一 ,具有重要的经济价值。过去曾有Norman( 1 92 3)、HoraandSilas( 1 95 1 )、褚新洛 ( 1 979、1 981 )、武云飞等 ( 1 979)、伍献文等( 1 981 )、岳佐和 ( 1 981 )、方树淼等 ( 1 984 )和丁瑞华等( 1 991、1 997)对我国西部及邻近国家的类进行了研究。 2 0世纪 80年代以来曾发现有 5个新种 ,至此该属共有 1 2种。同时…  相似文献   

5.
An investigation of polymorphism of 11 autosomal and one sex-linked allozyme loci was made on 18 samples of Anopheles claviger Meigen (Diptera: Culicidae) from localities across France and neighbouring sites in Germany and Switzerland, plus one sample of Anopheles petragnani Del Vecchio from the French Pyrénées. Genetic differentiation between these two sibling species was confirmed (Nei genetic distance 0.33-0.44) and two genetically distinct groups of populations were identified within An. claviger. These two forms of An. claviger showed contiguous geographical distributions, Group I found across western and Central France, Group II in eastern France and nearby parts of Germany and Switzerland. The two groups were in contact in a region near the Rhone Valley where two intermediate samples were found. The taxonomic significance of this finding is discussed in the context of the recent climatic history of Europe and in relation to the vector potential of each member of the An. claviger complex.  相似文献   

6.
7.
Original meiotic chromosome counts are presented for nine endemic species in seven families of Angiosperms from Iran including:Arum giganteum Ghahr. (Araceae) (n=14),Caccinia actinobole Bunge (Boraginaceae) (n=8),Delphinium aquilegifolium (Boiss.)Bornm. (Ranunculaceae) (n=8),Diplotaenia damavandica Mozaff., Hedge etLamond (Apiaceae) (n=11),Gypsophila caricifolia Boiss. (Caryophyllaceae) (n=17),Iphiona arachnoidea (Boiss.)Anderb. (Asteraceae) (n=9),Moltkia gypsacea Rech. f. etAellen (Boraginaceae) (n=20),Onobrychis gaubae Bornm. (Fabaceae) (n=8) andOnosma platyphyllum Riedl (Boraginaceae) (n=9). Eight counts are reported for the first time. Furthermore, the previous chromosome count forIphiona aracnoidea is corrected. Based on cytological data the species status ofMoltkia gypsacea is confirmed; it is not merely synonymous withM. coerulea (Willd.)Lehm. The basic chromosome number n=11 is reported in the genusDiplotaenia for the first time.  相似文献   

8.
9.
The lichen genus Erioderma is shown to be particularly species-rich in Ecuador, especially in the upper cloud forest (3000–3400m). Altogether seventeen species are recorded of which the following are new: E. barbellatum, E. cyathophorum, E. divisum, E. gloriosum, E. papyraceum, E. pycnidiferum, E. sinuatum , most of which also occur in the neighbouring countries. Two further taxa from these are described as new: E. latilobatum from Bolivia and E. peruvianum from Peru and Bolivia.  相似文献   

10.
Seven chromosome counts of six species from the family Asteraceae are reported. All taxa were collected from Hamedan province, Iran. One count is a new report (viz Inula aucheriana ), three are not in accordance with previous counts (viz Senecio glaucus, Tanacetum chiliophyllum and Tanacetum polycephalum ) and the others (viz Tripleurospermum disciforme, Tanacetum polycephalum , T. parthenium ) are confirmations of very limited (one to eight records) previous data. Most of the studied taxa have the basic number x=9, but Senecio glaucus has x = 10, with ploidy levels ranging from 2x to 8x. Both diploidy and triploidy were found in T. chiliophyllum and may be regarded as a sign of ongoing speciation.  相似文献   

11.
The speciesVicia bithynica andVicia narbonensis, from the same subgeneric section ofVicia faba, show variations in nuclear DNA content Nuclear DNAs, extracted from root tips of the twoVicia species, were characterized by thermal denaturation, analytical ultracentrifugation and reassociation kinetics. The thermal denaturations of DNA, the number of DNA components reassociating with second order kinetics, the proportion of repeated DNA sequences, the frequency of the repeated DNA classes are reported and compared to previous data onVicia faba DNA. Feulgen absorptions at different thresholds of optical density+ of interphase nuclei in cytological preparations of the root meristems ofV. bithynica andV. narbonensis are determined and compared withV. faba analogous determinations. The results, confirming that plant genome is highly flexible, are discussed in relation to other data on the interspecific variations of the nuclear DNA content.  相似文献   

12.
Two new species of the genus Thalictrum named Th. mazandaranicum Pakravan & Assadi and Th. tacabicum Pakravan & Assadi from Iran are described and illustrated, their differences to related species are discussed. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

13.
Five new species of the genus Poromitra (family Melamphaidae) belonging to the group of species P. crassiceps are described. An important specific feature of this group is the structure of praeoperculum in which bony crests of the anterior edge are at an acute angle to each other, and the posterior and lower edges are uniformly (without break) spinulated with small spinules. In P. decipiens sp. nova described from the Indian Ocean (from the East Indian Ridge), the insertion of ventral fins is located posteriorly the vertical of the posterior edge of pectoral fin insertion, which makes this species similar to P. crassiceps and P. rugosa. The remaining four species have the insertion of ventral fins anteriorly the vertical (or at its level) of the posterior edge of pectoral fin insertion (as in P. unicornis and P. coronata). P. curilensis sp. nova inhabits the northern part of the Pacific Ocean from the Kuril Islands and the Japanese Islands to the Gulf of Alaska; P. indooceanica sp. nova is described from several individuals from the subtropical part of the Indian Ocean; P. glochidiata sp. nova, from catch in the Great Australian Bight; and P. kukuevi sp. nova, from the individual from the western tropical part of the Atlantic Ocean.  相似文献   

14.
Summary Immediately prior to seed fill, a dermal transfer cell complex, comprised of epidermal and subepidermal cells, differentiates on the abaxial surface of the cotyledons in seed ofVicia faba. Over the period of differentiation of this complex in vivo, the principal sugars of the seed apoplasmic sap change from hexoses, glucose and fructose, to sucrose. Cotyledons were removed from seeds before differentiation of the transfer cell complex and cultured for 6 days on an agar-based medium in the dark with their abaxial surface in contact with a medium containing either 100 mM hexoses (glucose and fructose in equimolar concentrations) or 100 mM sucrose. On both media, cotyledon growth rate was maintained throughout the culture period at, or above, that of in vivo grown cotyledons of equivalent developmental age. When cotyledons were cultured on a medium containing glucose and fructose, epidermal cells of both the ab- and adaxial surfaces developed wall ingrowths on their outer periclinal walls and their cytoplasm became dense, vesicular, and rich in mitochondria. Extensive ingrowth deposition also occurred on walls of the subepidermal cells and several rows of underlying storage cells where they abutted intercellular spaces. This latter ingrowth development was apparent on both cotyledon surfaces, but extended into more of the underlying cell layers on the abaxial surface at the funicular end of the cotyledon. In in vivo grown cotyledons, such ingrowth development is restricted to the subepidermal cells of the abaxial surface. Ingrowth morphology was commensurate with that of transfer cells of in vivo grown cotyledons. In contrast to the observed induction on a medium containing glucose and fructose, cotyledons cultured with sucrose as the sole sugar source exhibited no ingrowth deposition or small wall ingrowths in some abaxial epidermal cells. While the potential sugar signalling mechanism is unknown, this culture system offers an exciting opportunity to explore the molecular biology of transfer cell development.Abbreviations DAA days after anthesis - GC-MS gas chromatography and mass spectrometry - PAR photosynthetically active radiation - RGR relative growth rate - SCM standard culture medium  相似文献   

15.
16.
Wolswinkel  P.  Ammerlaan  A. 《Planta》1983,158(3):205-215
Planta - Several characteristics of the process of phloem unloading in the seed coat of developing seeds ofVicia faba L. were investigated. Prior to the procedure of measuring the release of...  相似文献   

17.
18.
  • 1 The Eurasian beaver Castor fiber suffered a drastic reduction in both geographical range and population size, due to human persecution, until the end of the 19th century. After the adoption of protection measures, natural expansion and reintroductions led to the recovery of this species over much of its European range.
  • 2 We review historical events that led to the recovery of beavers in France, and summarize the status of beavers in various river systems. Beaver establishment in France is a story of overall success: several major river systems are presently occupied, so that the species is no longer at risk in France.
  • 3 However, beaver recolonization took place in parallel with increasing human impacts on the environment. In addition to natural limiting factors, anthropogenic factors impeded beaver settlement in many areas. Today, beavers often occupy suboptimal habitats and, as a consequence, come into conflict with human activities. Effective solutions for preventing beaver damage include the restoration of riparian habitats to discourage crop damage and the provision of physical barriers to protect crops.
  • 4 Beaver populations reintroduced into France all originate from the relict Rhône population. However, in recent years, beavers from populations in neighbouring countries have been expanding into north‐eastern France. Therefore, our review of beaver origin and distribution in these countries may contribute to the development of appropriate national management strategies and towards important decisions, e.g. the decision to try to keep Rhône beavers genetically isolated, or to allow populations to mix.
  • 5 The recently discovered presence of North American beavers Castor canadensis in three countries surrounding France has raised an important issue. This species may out‐compete C. fiber in places where the species come into contact. A programme based on field‐trapping sessions and genetic analyses has recently been initiated in some western countries in order to eradicate this non‐native species.
  相似文献   

19.
Karyological studies were performed on Hyoscyamus species of Iran. The species studied showed variation with regard to chromosome number and details of karyotype. Two different basic chromosome numbers of x=14 and 17 were recorded for the genus corresponding to the two subgenera of Hyoscyamus . Chromosome numbers of six species are reported for the first time.  相似文献   

20.
The importance of facilitative processes due to the presence of nitrogen-fixing legumes in temperate grasslands is a contentious issue in biodiversity experiments. Despite a multitude of studies of fertilization effects of legumes on associated nonfixers in agricultural systems, we know little about the dynamics in more diverse systems. We hypothesised that the identity of target plant species (phytometers) and the diversity of neighbouring plant species would affect the magnitude of such positive species interactions. We therefore sampled aboveground tissues of phytometers planted into all plots of a grassland biodiversity–ecosystem functioning experiment and analysed their N concentrations, δ15N values and biomasses. The four phytometer species (Festuca pratensis, Plantago lanceolata, Knautia arvensis and Trifolium pratensis) each belonged to one of the four plant functional groups used in the experiment and allowed the effects of diversity on N dynamics in individual species to be assessed. We found significantly lower δ15N values and higher N concentrations and N contents (amount of N per plant) in phytometer species growing with legumes, indicating a facilitative role for legumes in these grassland ecosystems. Our data suggest that the main driving force behind these facilitative interactions in plots containing legumes was reduced competition for soil nitrate (“nitrate sparing”), with apparent N transfer playing a secondary role. Interestingly, species richness (and to a lesser extent functional group number) significantly decreased δ15N values, N concentrations and N content irrespective of any legume effect. Possible mechanisms behind this effect, such as increased N mineralisation and nitrate uptake in more diverse plots, now need further investigation. The magnitude of the positive interactions depended on the identity of the phytometer species. Evidence for increased N uptake in communities containing legumes was found in all three nonlegume phytometer species, with a subsequent strong increase in biomass in the grass F. pratensis across all diversity levels, and a lesser biomass gain in P. lanceolata and K. arvensis. In contrast, the legume phytometer species T. pratense was negatively affected when other legumes were present in their host communities across all diversity levels.  相似文献   

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