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1.
Mismatch of morphological and molecular identifications in native and invasive subspecies of Codium fragile (Bryopsidophyceae,Chlorophyta)
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Several subspecies are defined within Codium fragile, including the invasive C. fragile ssp. fragile, first reported in New Zealand in 1973. An endemic subspecies, C. fragile ssp. novae‐zelandiae, is also found throughout New Zealand. The two subspecies exhibit morphological and molecular variation, although these have never been evaluated together. We compared variation between subspecies at locations in Auckland, identifying subspecies using rps3‐rpl16 DNA sequence data, and assessing gross morphological differences, anatomical utricle characters and morphometrics. The taxonomic utility of the morphometric data sets was assessed by linear discriminant analysis. Utricle characters and measurements varied within individual thalli and between different preservation methods. The phenotypes of both subspecies were highly variable and influenced by environment. Accurate subspecies delimitation using morphological data was not possible; the discriminant analyses performed no better than chance for all combinations of the morphological data. Specimens from New Zealand, Canada, Australia and Ireland were sequenced using both the rps3‐rpl16 and tufA plastid markers. The tufA elongation factor was shown to be a good candidate for differentiating subspecies of C. fragile. This marker is twice the length of the rps3‐rpl16 spacer, shows greater variation between ssp. fragile and novae‐zelandiae, and is less prone to sequencing error. A simple restriction enzyme digest of the tufA amplicon can distinguish ssp. fragile and ssp. novae‐zelandiae. Our study expands the known range of the ssp. fragile in New Zealand, including the first record of this subspecies from the west coast of Auckland, and points to a need to re‐evaluate morphological and molecular criteria for subspecies currently defined within C. fragile. 相似文献
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Stachyurus himalaicus ssp. purpureus Y. P. Zhu&Z. Y. Zhang,a new subspecies of Stachyuraceae from eastern Himalaya,is described. It differs from the typical subspecies,S. hi-malaicus ssp. himalaicus,by having purplish pink to dark purple flowers. The new subspecies oc-curs in Xizang(Tibet)of China,E Nepal,Sikkim,Bhutan,and NE India,usually growing in dense forests at an altitude between2200and3300m. 相似文献
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The section Acrocentron of the genus Centaurea in Greece is studied under the light of numerical taxonomy. The method used is the factor analysis of the correspondences. The taxonomic value of 68 morphological characters is examined. The section is divided into three subsections and one of them is further divided into smaller groups. C. spruneri is considered as a variable species within which no subspecies can be distinguished. C. achaia is classified as a synonym to C. sibthorpii C. redempta ssp. cytherea C. rupestris ssp. parnonia and C. rupestris ssp. kozanii are new combinations, which were formally made in Routsi (1993). Also, some recent views on the systematics of this section are confirmed. 相似文献
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MAX DEBUSSCHE JOHN D. THOMPSON 《Botanical journal of the Linnean Society. Linnean Society of London》2002,139(2):133-144
In Cyclamen subgenus Psilanthum , previous authors have recognized three species ( C. repandum, C. balearicum and C. creticum ), with C. repandum subdivided into three subspecies (ssp. repandum , ssp. peloponnesiacum and ssp. rhodense ), and two varieties (var. vividum and var. peloponnesiacum ) within C. repandum ssp. peloponnesiacum . To examine the validity of this classification and the degree of morphological differentiation among closely related endemic taxa with disjunct distributions, we undertook analyses of three quantitative and eight qualitative morphological traits of flowers and leaves, most of which have previously been used without statistical comparison in the classification of the different taxa. Cyclamen balearicum showed high levels of morphological differentiation from all other taxa in subgenus Psilanthum consistent with its specific status. In contrast, morphological differentiation between C. creticum and subspecies of C. repandum was similar to that among the three subspecies of C. repandum . When compared with a recent molecular phylogeny of this subgenus, our results suggest that C. creticum may best be described as a geographical subspecies of C. repandum . The two varieties of C. repandum ssp. peloponnesiacum showed few significant differences for individual traits and their overall morphology is very similar to each other. The morphology of plants at three sites on Corsica strongly suggest, consistent with molecular data, the occurrence of hybrid populations between C. balearicum (outside of its previously recognized distribution) and local C. repandum . © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 139 , 133–144. 相似文献
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YONG-SHAN LIAN XUE-LIN CHEN KUN SUN RUI-JUN MA 《Botanical journal of the Linnean Society. Linnean Society of London》2003,142(4):425-430
New information on (1) Hippophae goniocarpa Y.S. Lian et al . ex Swenson et Bartish and (2) H. goniocarpa ssp. litangensis (Lian et X.L. Chen ex Swenson et Bartish) Lian et K. Sun from China is provided and illustrated. Based on morphological characters and distribution, H. litangensis Y.S. Lian et X.L. Chen ex Swenson et Bartish is re-described as a subspecies. H. goniocarpa (including ssp. litangensis ) is a distinct species and should be placed in Section Gyantsensis of Hippophae , although it has been suggested that sspp. litangensis and goniocarpa are the result of hybridization between H. rhamnoides ssp. sinensis and H. neurocarpa ssp. neurocarpa , and H. rhamnoides ssp. yunnanensis and H. neurocarpa ssp. stellatopilosa , respectively. The type subspecies of H. goniocarpa is distributed in Songpan and Hongyuan Counties of Sichuan Province and Qilian County of Qinghai Province, at 3500–3750 m, whereas ssp. litangensis is found only in Jiawa, Litang County, Sichuan Province at c . 3700 m. A key including the four taxa of sect. Gyantsensis is provided. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 142 , 425−430. 相似文献
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中国特有植物卧龙沙棘自然群体的RAPD分析 总被引:1,自引:0,他引:1
应用12个随机引物对卧龙沙棘全部2居群共28个个体进行了RAPD分析。结果表明,卧龙沙棘具有较丰富的遗传多样性,多态位点百分率为78.05%,Nei’s基因多样性h=0.2553,Shannon’s多态性信息指数Ι=0.3841。分布范围狭窄的卧龙沙棘在亚种水平的遗传多样性明显高于分布较广的中国沙棘。在居群水平上,卧龙沙棘同样具有很高的遗传多样性,平均多态位点百分率为63.42%,Nei’s基因多样性h=0.2193,Shannon’s多态性信息指数I=0.3287。卧龙沙棘的基因分化系数Gst=0.1425,表明遗传变异主要存在于居群内。AMOVA的结果也表明,在全部的遗传变异中,19.18%的遗传变异存在于居群之间,与Gst值基本一致。这一结果符合卧龙沙棘风媒、异交的繁育系统特点。 相似文献
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Genetic variability in the federally endangered pitcher plant Sarracenia rubra ssp. alabamensis was assessed in eight Alabama populations using starch gel electrophoresis. Ten populations of the more widespread Sarracenia rubra ssp. rubra were sampled in the southeastern United States for comparison. Fifteen allozyme loci representing 13 enzyme systems were scored for each species. In contrast to S. oreophila and S. jonesii, two previously analyzed endangered pitcher plants, genetic diversity was high for both S. rubra subspecies. Within ssp. alabamensis the percentage polymorphic loci (Ps) was 80.0, the mean number of alleles per polymorphic locus was (APs) = 2.58, and expected heterozygosity (Hes) was 0.209. Genetic diversity was slightly lower for ssp. rubra (Ps = 73.3, APs = 2.91, and Hes = 0.177). The proportion of total genetic diversity found among populations was fairly low for both species (GST = 0.09 for ssp. alabamensis and 0.14 for ssp. rubra). Little genetic divergence has occurred between the two subspecies as indicated by the lack of diagnostic alleles, the proportion of total genetic diversity between taxa (GST = 0.09), and the genetic identity estimate (I = 0.90). The relatively high genetic diversity found for ssp. alabamensis indicates that the maintenance of its evolutionary potential is possible if population sizes are maintained or increased. Low levels of genetic diversity found within small Georgia ssp. rubra populations indicate that genetic erosion may increase extinction risks for these populations. 相似文献
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M. G. Gilbert 《Nordic Journal of Botany》2002,22(2):205-210
The following 4 species and 1 subspecies are described as new: Ceropegia recurvata, C. microgaster, C. erergotana, C.burgeri and Huernia macrocarpa subsp. harerghensis ; one variety of Ceropegia stenoloba is elevated to a full species: C. moyalensis and 2 species transferred from Angolluma to Pachycymbium: P. gilbertii and P. semitubißora. 相似文献
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Clarkia xantiana has two subspecies that differ in breeding system: ssp. xantiana, which is outcrossing, and ssp. parviflora, which is self-fertilizing. Outcrossing is the ancestral breeding system for the genus Clarkia. Flowers of ssp. parviflora have characteristics commonly associated with selfing taxa: they are smaller and have little temporal and spatial separation between mature anthers and stigma (dichogamy and herkogamy, respectively). Flower morphology and development were studied in four populations of each subspecies to establish the developmental changes that occurred in the evolution of selfing. In particular, we sought to evaluate the hypothesis that the selfing flower may have arisen as a byproduct of selection for rapid maturation in the arid environment occupied by ssp. parviflora. This hypothesis predicts that development time should be reduced in spp. parviflora relative to ssp. xantiana. We also sought to compare the pattern of covariation of flower morphology and development between subspecies to that within subspecies. Similar within vs. between patterns of covariation could be indicative of developmental or functional constraints on the independent evolution of floral parts. In spite of significant variation among populations within subspecies, the subspecies clearly differ in flower morphology and development. All floral organs, except ovaries, are smaller in ssp. parviflora than in ssp. xantiana. The flower plastochron, the duration of flower development from bud initiation to anthesis, and the duration of protandry are all shorter in ssp. parviflora than in ssp. xantiana. Maximum relative growth rates are higher for all organs in ssp. parviflora than in ssp. xantiana. Thus, progenesis (i.e., via a reduction in development time) is combined with growth acceleration in the evolution of the selfing flower. Since reduced development time and growth acceleration both allow selfing flowers to mature earlier than outcrossing ones, selection for early maturation may have contributed to the evolution of the selfing flower form. The pattern of trait covariation differs within spp. parviflora relative to the patterns within spp. xantiana and between the two subspecies, suggesting that floral parts can and have evolved independently of one another. 相似文献
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Communities dominated by Artemisia tridentata ssp. tridentata, A. tridentata ssp. wyomingensis, and A. tridentata ssp. vaseyana, found in the Piceance Basin of western Colorado, were evaluated for life history strategy. Species cover data were analyzed using Grime's (1984) triangular model. Then a canonical analysis was conducted to obtain an ordination of relative species cover. Results from these two analyses were then used to infer strategy differences among life histories of subspecies, based on the respective plant community associates. These differences were found to be consistent with the divergent evolution assumed to have occurred in this species. The primary ordination axis was interpreted as an elevation-moisture gradient. Further analysis of soil data by factor analysis also separated the three Artemisia subspecies along a soil texture gradient. 相似文献
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对Phryma leptostachya L.的亚洲产亚种,即ssp. asiatica (Hara) Kitamura作了分类修订,列出了显示两个亚种本质区别的检索表,并提供了ssp.asiatica的详细的地理分布资料。 相似文献
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The morphology, ultrastructure, density and distribution of trichomes on leaves of Betula pendula, B. pubescens ssp. pubescens, B. pubescens ssp. czerepanovii and B. nana were examined by means of light, scanning and transmission electron microscopy. The composition of flavonoids in ethanolic leaf surface extracts was analysed by high pressure liquid chromatography. All taxa examined contained both glandular and non-glandular trichomes (short and/or long hairs) but differed from each other in trichome ultrastructure, density and location on the leaf. Leaves of B. pubescens were more hairy than those of B. pendula, but the latter species had a higher density of glandular trichomes. Of the two subspecies of B. pubescens, leaves of ssp. pubescens had more short hairs on the leaf surface and four times the density of glandular trichomes of leaves of ssp. czerepanovii, whereas, in the latter subspecies, short hairs occurred largely on leaf veins, as in B. nana. The glandular trichomes were peltate glands, consisting of medullar and cortical cells, which differed structurally. Cortical cells possessed numerous small, poorly developed plastids and small vacuoles, whereas medullar cells had several large plastids with well-developed thylakoid systems and fewer vacuoles. In B. pubescens subspecies, vacuoles of the glandular cells contained osmiophilic deposits, which were probably phenolic, whereas in B. pendula, vacuoles of glandular trichomes were characterized by the presence of numerous myelin-like membranes. The composition of epicuticular flavonoids also differed among species. The two subspecies of B. pubescens and B. nana shared the same 12 compounds, but five of these occurred only in trace amounts in B. nana. Leaf surface extracts of B. pendula contained just six flavonoids, three of which occurred only in this species. In summary, the structure, density and distribution of leaf trichomes and the composition of epicuticular flavonoids represent good taxonomic markers for Finnish birch species. 相似文献
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Comparison of salt tolerance and osmotic adjustment of low-sodium and high-sodium subspecies of the C4 halophyte, Atriplex canescens 总被引:1,自引:1,他引:0
The relationship between Na+ accumulation and salt tolerance was tested by comparing subspecies of the halophyte, Atriplex canescens (fourwing saltbush), that differed markedly in Na+ content and Na:K ratios. Above ground tissues of one low-sodium and two high-sodium subspecies were compared with respect to cation accumulation, osmotic adjustment and growth along a salinity gradient in greenhouse trials. Plants of each subspecies were grown for 80 d on 2.2, 180, 540 and 720 mol m?3 NaCl. At harvest, A. canescens ssp. canescens had significantly lower Na+ levels, higher K+ levels and lower Na:K ratios in leaf and stem tissues than A. canescens ssp. macropoda and linearis over the salinity range (P < 0.05 or 0.01). Na:K ratios in leaves of the latter two, high-sodium, subspecies were approximately 2 on the lowest salinity treatment and ranged from 5 to 10 on the more saline solutions. By contrast, Na:K ratios in leaves of the low-sodium subspecies canescens, were only 0.4 on the lowest salinity and ranged narrowly from 1.7 to 2.3 at higher salinities. However, despite different patterns of Na+ and K+ accumulation, all three subspecies exhibited equally high salt tolerance and had similar osmotic pressures in their leaves or stems over the salinity range. Contrary to expectations, high salt tolerance was not necessarily dependent on high levels of Na+ accumulation in this species. 相似文献
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Water efflux from the surface of field-grown grass roots. Observations by cryo-scanning electron microscopy 总被引:4,自引:0,他引:4
M. E. McCully 《Physiologia plantarum》1995,95(2):217-224
The objective of this study was to compare whole plant growth and physiological responses to salt stress of two Acacia nilotica subspecies (ssp. cupressiformis and ssp. tomentosa ). Salt stress was induced by adding NaCl at different concentrations to the nutrient solution: 0, 75, 100 and 200 m M . After one month under such stress, plants were still healthy and actively growing in both subspecies up to 100 m M NaCl. Water potential (Ψ) and osmotic potential (π) decreased with salinity and the lower π enabled the plants to maintain turgor. Höfler diagrams confirmed that osmotic adjustment had occurred under all treatments. Furthermore, the point of zero turgor occurred at a higher relative water content. An increase in the elastic modulus (ɛ) was observed under stress (low elasticity of the cell wall). Both osmotic adjustment and a high ɛ modified the capacity of both subspecies to maintain a positive water balance. Accumulation of ions (Na+ , K+ and Cl− ) and proline could explain such osmotic adjustment. Acacia nilotica ssp. cupressiformis showed a higher absorption of K+ than ssp. tomentosa up to 100 m M NaCl treatment. 相似文献
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作者在给中国科学院植物研究所生态室鉴定标本时, 发现一西藏新记录属--黧豆属(Mucuna Adans.), 所鉴定标本是多褶果黧豆Mucuna hainanensis ssp.multilamellata Wilmot-Dear, 为一中国新记录亚种, 现特予报道。 相似文献