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1.
Tissue culture techniques for the propagation and conservation of endemic or threatened plants can be used to complement the methods usually applied in ex situ conservation. Thus, Minuartia valentina (Caryophyllaceae), an endangered plant species endemic to the Valencia Community (Eastern Spain), was successfully regenerated through shoot proliferation from wild plants growing in their natural area. Nodal segments, 10~mm long, were cut from rametes of adult material, sterilised and established in vitro. Equally successful shoot multiplication was achieved on Murashige and Skoog (MS) medium with 80 mg l-1 phloroglucinol in combination with either 1 mg l-1 6-benzylaminopurine or 1 mg l-1 kinetin. Excised shoots were rooted in MS medium supplemented with an auxin (indole acetic acid, indole-3-butyric acid, or napththalene acetic acid). Shoots rooted well (96–100%) within three weeks in all auxin treatments. However, the use of napththalene acetic acid was discarded because this auxin delayed root differentiation, and induced adventitious root malformation. Rooted plantlets were transferred to pots and 85% of them acclimatized successfully four weeks after transfer to greenhouse conditions, where they exhibited normal morphology and growth. 相似文献
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Ten species of Lepadella Bory de St. Vincent, 1826, including one new species and one new form, are documented from North-Eastern India. Two of these species are new records from this country and six are new reports from N.E. region. Comments are also made on the status and distribution of various Indian taxa. 相似文献
4.
The described fossil testudinids from the Miocene of Africa are reviewed. Geochelone stromeri sp. nov . is described from Lower Pliocene (Langebaanweg) and Miocene (Namib) specimens. Kinixys erosa , an extant species, is reported from Songhor Hill. Chersina sp. is reported from Arrisdrift. Impregnochelys pachytectis gen. et sp. nov . is described from Rusinga Island, Kenya, and is unique in having the anterior shell opening orientated ventrally and in having struts on the internal surface of the neurals, but shares with Kinixys a unique epiplastron shape, a high number of axillary scutes and unique orientation of the head of the femur. 相似文献
5.
Bruce M. Campbell 《Plant Ecology》1986,66(1):3-16
The vegetation of the mountains of the Fynbos Biome is classified and described, mostly on the basis of vegetation structure and higher taxa. Various gradients can be recognized. A gradient in soil conditions runs from coarse textured, nutrient-poor soils in non-grassy fynbos (Mountain Fynbos) through grassy fynbos and grassy non-fynbos (Eastern Fynbos and Grasslands & Grassy Shrubland) to finer textured and less nutrient-poor soils in the non-fynbos Karroid & Renoster Shrubland. Another gradient of significance can be likened to the tropical gradient running from the dry conditions of hot semi-deserts to savannas or grasslands to woodlands. At the dry extreme an open shrubland occurs (Karroid & Renoster Shrubland, Asteraceous Fynbos), at intermediate positions a herbland occurs (Restioid Fynbos) and at the wet extreme another type of shrubland occurs (Ericaceous Fynbos). This kind of moisture gradient occurs on individual mountains with the xeric end being at the base of the north slopes, and the mesic end being on the upper south aspects. Soil characteristics are closely linked to this gradient; the better developed soils being found on the south aspects. Another moisture gradient is apparent in the vegetation. This gradient runs from the mesic southern coastal mountains to the north west where summer droughts are extremely severe although total rainfall may be similar.Nomenclature follows that used in the Government Herbarium, Stellenbosch.I thank William Bond, Richard Cowling, John Rushworth, Eddy van der Maarel and Marinus Werger for critical comments and discussion. 相似文献
6.
Distributional change and conservation on the Andean flank: a palaeoecological perspective 总被引:3,自引:0,他引:3
Mark B. Bush 《Global Ecology and Biogeography》2002,11(6):463-473
Aim To review the insights that palaeoecology can offer on the threat posed to Andean communities by global climate change. Location The geographical focus is the eastern flank of the tropical Andes, with particular reference to Peru. Method The article presents a synthetic review of the problem. Results Species‐rich communities of the eastern Andean flank are threatened both by development and climate change. If, as predicted, the cloudbase and frost line lifts 600 m elevation this century, there will be a substantial loss of cloud forest habitat. Palaeoecology provides insights on the location and nature of past ecotones, the continuity of niche availability, and estimates for rates and modes of migration. With further warming and drying of lower montane regions, upslope migration of species will be individualistic: a new equilibrium with the altered climate is unlikely to be attained. The zone of agriculture will move upslope faster than the migrating trees and so landscape conversion will negate the ability of some species to respond to the new conditions. Conservation of the lower reaches of modern cloud forest is advocated as a means to limit this foreseeable extinction event. Main Conclusions Climate change will induce changes in plant and animal communities. Human disturbance will invade climatically marginal agricultural lands at the pace of climate change. Rapid migratory response such as that witnessed at the onset of the Holocene may not be evident as climates warm, because Holocene climatic stability has reduced outlying upslope populations that may have served as expansion nuclei. Conservation must aim to maintain plant and animal niches, rather than particular communities of species. 相似文献
7.
Yu. S. Repin 《Paleontological Journal》2008,42(3):243-250
Three new subgenera, Gervillaria (Platygervillaria), Isognomon (Iranognomon), and Mytilaster (Persiaster), and seven new species, Gervillaria (Platygervillaria) alifera, Isognomon (Iranognomon) arkelli, Inoperna (Inoperna) striata, Mytilaster (Persiaster) ancestralis, Astarte persipulla, Orthotrigonia fazli, and Gissaromya abramovi, from the Jurassic of Iran are described. 相似文献
8.
Freshwater finfish species richness and level of endemism in East, and South and South‐East Asia that included 17 nations were studied using available databases, and included nation‐wise distribution, habitat types, and conservation status. The number of endemic finfish species in the region was 559, belonging to 47 families. Families Cyprinidae and Balitoridae accounted for 43.5% and 16.2% of the total number of endemic species in the region, respectively, followed by Sisoridae (25), Gobiidae (20), Melanotaeniidae (19), and Bagridae (16), and the other 41 families had at least one endemic species. Nation‐wise the most number of endemic freshwater finfish species occur in India (191), followed by China (88), Indonesia (84), and Myanmar (60). In India, the endemic species accounted for 26.4% of the native freshwater fish fauna, followed by South Korea (16.9%), the Philippines, (16.3%) and Myanmar (15.7%). Statistically significant relationships discerned between the number of indigenous and endemic species richness to land area (Xla in 103 km2) of the nations in the region were, Yin = 218.961 Ln(Xla) – 843.1 (R2 = 0.735; P < 0.001) and Ye = 28.445 Ln Xla?134.47 (R2 = 0.534; P < 0.01), respectively, and between indigenous and endemic species richness was Ye = 0.079Xn? 1.558 (R2 = 0.235; P < 0.05). The overall conservation status of endemic finfish in Asia was satisfactory in that only 92 species were in some state of vulnerability, of which 37 species (6.6%) are endangered or critically endangered. However, the bulk of these species (83.7%) were cave‐ and or lake‐dwelling fish. However, nation‐wise, the endemic freshwater finfish fauna of the Philippines and Sri Lanka, based on the imperilment index, were found to be in a highly vulnerable state. Among river basins, the Mekong Basin had the highest number of endemic species (31.3%). The discrepancies between databases are highlighted and the need to consolidate information among databases is discussed. It is suggested that the Mekong Basin be considered as a biodiversity hotspot, and appropriate management strategies be introduced in this regard. 相似文献
9.
J. M. Miller J. W. Kijas M. P. Heaton J. C. McEwan D. W. Coltman 《Molecular ecology resources》2012,12(6):1145-1150
Recent advances in technology facilitated development of large sets of genetic markers for many taxa, though most often model or domestic organisms. Cross‐species application of genomic technologies may allow for rapid marker discovery in wild relatives of taxa with well‐developed resources. We investigated returns from cross‐species application of three commercially available SNP chips (the OvineSNP50, BovineSNP50 and EquineSNP50 BeadChips) as a function of divergence time between the domestic source species and wild target species. Across all three chips, we observed a consistent linear decrease in call rate (~1.5% per million years), while retention of polymorphisms showed an exponential decay. These results will allow researchers to predict the expected amplification rate and polymorphism of cross‐species application for their taxa of interest, as well as provide a resource for estimating divergence times. 相似文献
10.
DAVID A. SIMPSON fls A. MUTHAMA MUASYA KONGKANDA CHAYAMARIT JOHN A. N. PARNELL fls SOMRAN SUDDEE BART D. E. WILDE MICHAEL B. JONES JEREMY J. BRUHL RACHUN POOMA 《Botanical journal of the Linnean Society. Linnean Society of London》2005,149(3):357-364
Khaosokia caricoides , D.A. Simpson, Chayam. & J. Parn., a newly discovered genus and species of Cyperaceae is described and illustrated. The genus is characterized by a narrowly paniculate dioecious inflorescence with 2–4 nodes, each of the nodes having a leaf-like inflorescence bract that exceeds the inflorescence. Spikelets in both sexes are linear-cylindric and each flower has seven perianth bristles. The nutlet was immature in the specimens examined. The photosynthetic pathway is C3 . Khaosokia is endemic to limestone cliffs in peninsular Thailand; its conservation status is assessed as Vulnerable (VU B1a + 2a). It has affinities to tribes Cariceae, Dulichieae and some members of Scirpeae, but the exact nature of these relationships has yet to be determined. A revised key to the genera of Cyperaceae in Thailand is presented. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 357–364. 相似文献