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1.
Faberia Hemsl., a small genus of six species in the tribe Cichorieae, Asteraceae, has been karyologically investigated for the first time. All four studied species were revealed to have the somatic chromosome number 2n = 34, and thus the basic number of the genus was assumed to be x = 17. This rather high basic number has been previously reported very rarely in the tribe, occurring otherwise only in Warionia Benth. & Coss., a monospecific genus endemic to northwestern Africa, and in the American species of Lactuca L. The chromosome morphology was very similar among the four species, with the majority being median centromeric (m) and a few submedian centromeric (sm). In all the karyotypes the chromosomes were medium‐sized (6.33–1.61 μm), and showed a steady gradation in length from the longest to the shortest, with no evidence of bimodality. Our results strongly support the recognition of Faberia as an independent genus and the inclusion of Faberiopsis Shih & Y. L. Chen in Faberia.  相似文献   

2.
Recent molecular phylogenetic analyses indicate that Dubyaea glaucescens (Compositae–Cichorieae) should be transferred to the genus Faberia as F. glaucescens. Here, we present cytological evidence for this transfer. Dubyaea glaucescens comprises two ploidy levels, 2n = 34 (diploid) and 2n = 51 (triploid), making the basic chromosome number x = 17. The chromosomes vary in length from 5.82 μm to 2.11 μm, and the karyotypes are 2n = 20m + 14sm (3sat) for the diploid cytotype and 2n = 30m + 21sm (3sat) for the triploid cytotype. Karyological characters of D. glaucescens, including chromosome number, size, morphology, and karyotype asymmetry, all agree remarkably with those reported previously in Faberia, but are distinct from those in other species of Dubyaea. The transfer of D. glaucescens to Faberia is thus strongly corroborated.  相似文献   

3.
The chromosome numbers and morphology in 92 populations belonging to 49 species and three varieties in the genus Delphinium L. (Ranunculaceae), mostly from the Hengduan Mountains region of south‐west China, were studied. Forty seven species and three varieties were diploid, with 2n = 16, one species was tetraploid, with 2n = 32, and one species had diploid and tetraploid cytotypes. Three species had B chromosomes, representing the first time the occurrence of B chromosomes has been reported in the genus. The karyotypes of all the diploid species were quite uniform, commonly bimodal, and usually consisted of one pair of large median‐centromeric (m), one pair of large submedian‐centromeric (sm), five pairs of medium‐sized subterminal‐centromeric (st), and one pair of smaller sm (rarely st) chromosomes. The low incidence of polyploids in Delphinium from the Hengduan Mountains region indicates that polyploidy has played a minor role in the speciation of this highly diversified genus in the region. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 172–188.  相似文献   

4.
梁红艳  姜效雷  孔玉华  杨喜田 《生态学报》2018,38(23):8345-8353
为了阐明气候变暖背景下春兰(Cymbidium goeringii)和蕙兰(C. faberi)在我国的适生区分布变化情况,根据157条分布记录和19个生物气候变量,应用最大熵物种分布模型,对2070年4种温室气体排放情景下春兰和蕙兰在我国的适生区分布进行预测,并筛选影响其地理分布的主要气候因子。结果表明:(1)2070年春兰和蕙兰分布点的年均温(bio1)、最冷月最低温度(bio6)和最冷季平均温度(bio11)等均升高,气候有变暖趋势;(2)受试者工作特征曲线下面积(AUC)值在0.9—1.0之间,模型预测结果可信度较高;(3)影响春兰、蕙兰当前和2070年地理分布的限制性气候因子主要有最冷月最低温度(bio6)、最冷季平均温度(bio11)、年均降水量(bio12)和最干月份降水量(bio14);(4)气候变暖将会对春兰和蕙兰的适宜生境范围和面积产生影响。预测2070年春兰的适宜生境面积将会有所减小,而蕙兰的适宜生境面积将会增加,且整体有向北迁移的趋势。研究结果为野生春兰和蕙兰的生态风险评价和引种提供了重要依据。  相似文献   

5.
西藏兰科新记录   总被引:1,自引:0,他引:1  
报道了兰科(Orchidaceae)高山铠兰[Corybas himalaicus (King & Pantl.) Schltr.]和山珊瑚(Galeola faberi Rolfe)在中国西藏自治区的分布新记录。高山铠兰形态上因唇瓣先端边缘齿蚀状,花瓣与侧萼片在基部贴生,长7~8 mm,距暗红色而区别于铠兰属其他种;山珊瑚形态上因萼片狭椭圆形,唇瓣上散生褶片状附属物,边缘不规则齿状而区别于山珊瑚属其他种。凭证标本存放于广西药用植物园标本馆(GXMG)。  相似文献   

6.
为揭示不同菌根类型树种细根化学计量学性状对N添加的塑性响应,在福建省建瓯市万木林自然保护区常绿阔叶林内选择外生菌根树种罗浮栲(Castanopsis faberi)和内生菌根树种木荷(Schima superba)为研究对象,采用根袋法开展N添加试验,细根在根袋内生长半年后测定化学计量学指标(C、N、P、C/N、N/P、C/P)。结果表明:根序对细根化学计量学性状有显著影响,随着根序的增加,罗浮栲与木荷细根C浓度、C/N、C/P明显增加,N浓度与P浓度明显下降。N添加对细根C、N浓度均有极显著的促进作用,但对细根P浓度影响不显著,从而导致细根C/N维持稳定,但N/P、C/P升高,细根受P限制增加。细根化学计量学性状对N添加的塑性响应在不同序级间以及在外生菌根树种罗浮栲和内生菌根树种木荷之间均无显著差异。结论表明,研究所选内生、外生菌根树种细根化学计量学性状对N添加具有基本相似的响应。  相似文献   

7.
The red panda Ailurus fulgens Cuvier, 1825 is endemic to the Himalayan-Hengduan Mountains. Many of its ecological traits are still poorly understood although important from a scientific standpoint as a highly specialized bamboo feeder. To understand its food habits and space-use, we carried out a field study from April 2002 to May 2003 in Fengtongzhai Nature Reserve, China. The results showed that red pandas almost exclusively fed on Bashania faberi, but not on Yushania brevipaniculata in the study area. Besides differences in nutritional quality, accessibility to food items is perhaps another factor affecting their utilization of bamboo species. B. faberi leaves are the highest in crude protein, being the primary year-round food source; new shoots and fruits of Sorbus, and Rubus are nutritious and digestible, seasonally occurred in their diet. Red pandas seemed to select most nutritious food items to feed on. The home range of red pandas averaged 2.2 km2 across individuals (2.6 km2 for the males and 1.7 km2 for the females), and overlapped extensively (ranging 18.9–78.1%). No significant difference was found in monthly percentage of total home range used among seasons and sexes. The daily movement distance was 455 m (447 m for the females and 463 m for the males), significantly affected by sexes and months. Our findings indicated that food resource significantly influenced behaviour of red pandas in foraging and space use, and their behavioural responses are adaptive being helpful to energy intake and maintenance.  相似文献   

8.
9.
M. A. Motara 《Chromosoma》1982,86(3):319-323
C-banding karyotypes of three Culex species, C. fatigans, C. univittatus, and C. tigripes have been described. In all three species the female determining chromosome possesses a centromeric as well as an intercalary band. The male determining chromosome in all of them has a centromeric band only. The A. aegypti C-banding karyotype is as described by Motara and Rai (1977).  相似文献   

10.
报道了产自湖南省沅陵县的2个湖南省植物新记录属[裸芸香属(Psilopeganum Hemsl.)、野丁香属(Leptodermis Wall.)]和7个湖南省新记录种[裸芸香(Psilopeganum sinense Hemsl.)、野丁香(Leptodermis potanini Batalin)、稻草石蒜(Lycoris straminea Lindl.)、珠芽虎耳草(Saxifragagranulifera Harry Smith)、祛风藤(Biondia microcentra(Tsiang)P.T.Li)、荠苨(Adenophora trachelioides Maxim.)和西南齿唇兰(Odontochilus elwesii C.B.Clarke ex J.D.Hooker)],并对新记录植物的地理意义进行了简要分析。  相似文献   

11.
Centromeric chromatin in most eukaryotes is composed of highly repetitive centromeric retrotransposons and satellite repeats that are highly variable even among closely related species. The evolutionary mechanisms that underlie the rapid evolution of centromeric repeats remain unknown. To obtain insight into the evolution of centromeric repeats following polyploidy, we studied a model diploid progenitor (Gossypium raimondii, D‐genome) of the allopolyploid (AD‐genome) cottons, G. hirsutum and G. barbadense. Sequence analysis of chromatin‐immunoprecipitated DNA showed that the G. raimondii centromeric repeats originated from retrotransposon‐related sequences. Comparative analysis showed that nine of the 10 analyzed centromeric repeats were absent from the centromeres in the A‐genome and related diploid species (B‐, F‐ and G‐genomes), indicating that they colonized the centromeres of D‐genome lineage after the divergence of the A‐ and D‐ ancestral species or that they were ancestrally retained prior to the origin of Gossypium. Notably, six of the nine repeats were present in both the A‐ and D‐subgenomes in tetraploid G. hirsutum, and increased in abundance in both subgenomes. This finding suggests that centromeric repeats may spread and proliferate between genomes subsequent to polyploidization. Two repeats, Gr334 and Gr359 occurred in both the centromeres and nucleolar organizer regions (NORs) in D‐ and AD‐genome species, yet localized to just the NORs in A‐, B‐, F‐, and G‐genome species. Contained within is a story of an established centromeric repeat that is eliminated and allopolyploidization provides an opportunity for reinvasion and reestablishment, which broadens our evolutionary understanding behind the cycles of centromeric repeat establishment and targeting.  相似文献   

12.
Karyomorphological comparisons were made of five species of JapaneseWoodwardia. There were no marked differences at interphase and prophase among the five species.Woodwardia japonica, W. prolifera, andW. unigemmata were diploid with 2n=68 and the formulas of their metaphase karyotypes uniformly 4m(median centromeric chromosomes)+12sm(submedian)+52(st+t)(subterminal and terminal).Woodwardia orientalis was tetraploid with 2n=136 and 8m+24sm+104(st+t), and the ratio of each chromosomal type to total complement was identical to that of three diploid species. These four species had several characteristics in common:x=34, the longest chromosome of sm, and a mean chromosome length over 3.0 μm. AlthoughWoodwardia orientalis showed some similarity toW. prolifera, it seems to be an allotetraploid which originated by chromosome doubling of a hybrid ofW. prolifera and a diploid species as yet karyomorphologically unknown.Woodwardia kempii was tetraploid with 2n=124 and 8m+24sm+92(st+t), and differed from the others in havingx=31, the longest chromosomes of t, and a mean chromosome length under 3.0 μm. This species has been classified as an independent genus,Chieniopteris, and our karyomorphological study supports this treatment.  相似文献   

13.
Saito Y  Edpalina RR  Abe S 《Genetica》2007,131(2):157-166
Satellite DNA clones with a 37 bp repeat unit were obtained from BglII-digested genomic DNA of Masu salmon (Oncorhynchus masou) and Chum salmon (O. keta). Fluorescence in situ hybridization (FISH) analysis with the isolated clones as a probe showed that these repetitive sequences were localized in the telomeric regions of chromosomes in both species. Southern and dot blot analyses suggested conservation of homologous sequences with similar repeat unit in other salmonids including the species of the genus Oncorhynchus and Salvelinus, but lack or scarcity of such sequences in the genus Hucho and Salmo. Similarly, polymerase chain reaction (PCR)-based cloning of satellite DNA referring to a reported Rainbow trout (O. mykiss) centromeric sequence was successful for the Oncorhynchus, Salvelinus and Hucho species. The obtained satellite DNA clones were localized with FISH in the centromeric regions of chromosomes of the species from these three genera. Although PCR cloning of the centromeric satellite DNA had failed in the Salmo species due to some base changes in the priming sites, dot blot hybridization analysis suggested conservation of homologous satellite DNA in the genus Salmo as in the other three genera. In the neighbor-joining tree of cloned centromeric satellite DNA sequences, the genus Oncorhynchus and Salvelinus formed adjacent clades, and the clade of the genus Hucho included the reported centromeric sequence of the genus Salmo. Conservation pattern and molecular phylogeny of the telomeric and centromeric satellite DNA sequences isolated herein support a close phylogenetic relationship between the genus Oncorhynchus and Salvelinus and between the Salmo and Hucho.  相似文献   

14.
A new species of pipefish Leptonotus vincentae sp. nov. (Syngnathidae) is described on the basis of 12 specimens found in shallow waters (<2 m depth) of San Antonio Bay, Patagonia, Argentina, in the south-west Atlantic Ocean. The species is distinguished from congeners by the combination of: dorsal-fin rays 30–33, pectoral-fin rays 12–13, trunk rings 18–19, tail rings 43–46, subdorsal rings (2–4) + (5.5–8) = (8.5–10), head length 13–14% standard length, snout length 35–55% head length and snout depth 21–30% in snout length. Although this species has often been mistaken for Leptonotus blainvilleanus, most diagnostic characters of the two species differ. Both species are clearly distinguished by their snout length. L. blainvilleanus has a relatively longer snout than L. vincentae sp. nov. The new species is similar to a south-west Pacific species, Leptonotus elevatus. However, L. vincentae sp. nov. differs from this species in that it exhibits a lower number of dorsal-fin rays and a relatively longer head.  相似文献   

15.
A PstI DNA family was isolated from the genome of a lacertid, Lacerta graeca. The 185-bp monomeric unit (pGPS) was cloned and hybridized to DNAs and chromosomes of several lacertid species. The data showed that pGPS hybridizes to the (1) centromeric or pericentromeric heterochromatin of almost all the chromosomes of L. graeca and (2) genomic DNA of species phylogenetically related and unrelated to L. graeca. The presence of pGPS even in species immunologically apart more than 30 million years suggests that this repeated family might be either very ancient or have been conserved during evolution due to its functional role. The latter hypothesis might be supported by the results of sequence analysis which showed some homology with both several alphoid sequences of primates and the CDEIII centromeric sequence of yeast. Segments of the satellite sequence are similar to the mammalian CENP-B box. These observations suggest that pGPS might have a role in determining the centromeric function in lacertid lizards. Received: 6 February 1997 / Accepted: 14 May 1997  相似文献   

16.
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   

17.
The genus Tetradium Lour. is discussed with special reference to taxa in cultivation and the most widely planted species, Tetradium daniellii, (commonly called Euodia daniellii (Benn.) Hemsl. or E. hupehensis Dode) which is the subject of this plate. Its variation, synonymy, history and cultivation are reviewed.  相似文献   

18.
Five species belonging to the family Prymnesiaceae (one Prymnesium and four Chrysochromulina) have been identified in cultures obtained from water collected in the Bay of Banyuls‐sur‐Mer (Mediterranean Sea, France) using LM, SEM, and TEM. Two are described as new species, Chrysochromulina lanceolata sp. nov. and C. pseudolanceolata sp. nov. Both species are large and lanceolate with an acute posterior and two anterior arms. They are easily detectable with LM but difficult to distinguish to species level with live cells, without experience. EM reveals two completely different scale patterns in the two species. Cells of C. lanceolata are 21–38 μm long, 7–12 μm wide, and 3–7 μm thick. They possess two subequal flagella (30–51 and 29–44 μm), and the haptonema is shorter than the flagella (23–37 μm). The cell body is covered by plate and spine scales. Cells of C. pseudolanceolata sp. nov. are slightly smaller (15–18 × 6–8 μm) with more rounded extremities, two subequal flagella (19–26 and 17–24 μm), and the haptonema is longer than the flagella (about 35 μm). Three types of plate scales are observed in this species. Other findings are C. alifera Parke et Manton and C. throndsenii Eikrem (a new record for the Mediterranean Sea). Prymnesium faveolatum Fresnel, a new toxic species recently described, is illustrated with both LM and SEM.  相似文献   

19.
报道了陕西省种子植物区系2新记录属[茜草科(Rubiaceae)的虎刺属(Damnacanthus Gaertn.f.),桔梗科(Campanulaceae)的刺萼参属(Echinocodon Hong)],3新记录种[四川虎刺(Damnacanthus officinarum Huang),刺萼参(Echinocodon lobophyllus Hong)及报春花科(Primulaceae)的异花珍珠菜Lysimachia crispidens(Hance)Hemsl.]。  相似文献   

20.
ABSTRACT. Thirty-eight of 51 (74.5%) shrew moles collected in Japan were infected with from one to four species of Eimeria and/or Isospora including six of six Dymecodon pilirostris and 32 of 45 (71.1%) Urotrichus talpoides. Four eimerians and two isosporans were identified and all are described as new species. Sporulated oocysts of Eimeria amorphospora n. sp. were subspheroid/ellipsoid, 21.1 × 17.9(18-25 × 16-21) μm. Sporocysts were amorphous, gelatinoid envelopes 20.3 × 7.5 (17–24 × 7–9) μm. Sporozoites were enclosed together within a membrane in each sporocyst. This species was found in 9 of 45 (20%) U. talpoides. Sporulated oocysts of Eimeria gonocilia n. sp. were subspheroid/ellipsoid, 28.8 × 24.4 (25–30 × 21–28) μm; a highly ornate outer oocyst wall gave the appearance of a ciliated ball. Sporocysts ovoid, pointed at both ends, were 17.0 × 9.0 (15–19 × 7–11) μm; this species was found in 4 of 45 (8.9%) U. talpoides. Sporulated oocysts of Eimeria talpoidei n. sp. were asymmetrical ovoid, 20.6 × 13.3 (18–23 × 12–15) μm, with sporocysts lacrimiform, 12.0 × 5.8 (10–14 × 5–7) μm. This species was found in 7 of 45 (15.6%) U. talpoides. Sporulated oocysts of Eimeria honshuensis n. sp. were ellipsoid, 15.5 × 11.4 (13–18 × 10–13) μm, with sporocysts ovoid, 9.1 × 5.2 (8–10 × 4–6) μm. This species was found in 10 of 45 (22.2%) U. talpoides and in 5 of 6 (83.3%) D. pilirostris. Sporulated oocysts of Isospora dymecodi n. sp. were subspheroid/ellipsoid, 15.8 × 12.6 (13–17 × 11–13) μm, with sporocysts ellipsoid, 10.9 × 6.9 (10–13 × 6–8). This species was found in six of six D. pilirostris. Sporulated oocysts of Isospora urotrichi n. sp. were spheroid/subspheroid, 13.4 × 12.4 (11–16 × 9–14) μm, with sporocysts ovoid, 9.2 × 6.3 (8–11 × 5–7) μm. This species was found in 27 of 45 (60%) U. talpoides. Only 14 of 38 (36.8%) infected hosts (one D. pilirostris, 13 U. talpoides) were seen to be naturally infected with only one coccidian species when sampled.  相似文献   

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