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1.
The Cuban species of Calisto are reviewed based on the morphology of adult and immature stages, as well as DNA sequences of six genes (COI, EF1α, wingless, GAPDH, RpS5, CAD). A new species, Calisto occultasp. n., is described from the northeastern Cuban mountains. Calisto smintheus Bates, 1935 and Calisto bruneri, Michener 1949 are revised and revalidated. A new status, the species level, is proposed for Calisto brochei, Torre 1973, Calisto muripetens, Bates 1939 and Calisto bradleyi, Munroe 1950. The immature stages of Calisto smintheus, Calisto brochei,and Calisto occulta are described for the first time, and those of Calisto herophile, Hübner 1823 are redescribed. Useful morphological characters for adults are the shape and conspicuousness of androconial patch, the number and relative size of white dots on underside of hindwing, the shape of aedeagus, the shape of digitiform projection of genitalia valve, the shape and relative size of tegumen and uncus, the relative size of female genitalia, the height of sterigmal ring dorsal crown of the latter, and the relative size of corpus bursae and ductus bursae. For the immature stages, the most important characters are the color pattern of head capsule, the number and width of longitudinal lines of body, in the larvae; and the color pattern and the absence or presence of dorsal ridges on the abdomen of pupae. The phylogenetic relationships between the Cuban Calisto species are quite robust and well-supported; however, conflict between mitochondrial and nuclear datasets was detected in Calisto brochei, Calisto muripetens and to a lesser degree in Calisto bradleyi.  相似文献   

2.
B. A. Manny  D. Kenaga 《Hydrobiologia》1991,219(1):269-279
Despite extensive urbanization of its watershed, the Detroit River still supports diverse fish and wildlife populations. Conflicting uses of the river for waste disposal, water withdrawals, shipping, recreation, and fishing require innovative management. Chemicals added by man to the Detroit River have adversely affected the health and habitats of the river's plants and animals. In 1985, as part of an Upper Great Lakes Connecting Channels Study sponsored by Environment Canada and the U.S. Environmental Protection Agency, researchers exposed healthy bacteria, plankton, benthic macroinvertebrates, fish, and birds to Detroit River sediments and sediment porewater. Negative impacts included genetic mutations in bacteria; death of macroinvertebrates; accumulation of contaminants in insects, clams, fishes, and ducks; and tumor formation in fish. Field surveys showed areas of the river bottom that were otherwise suitable for habitation by a variety of plants and animals were contaminated with chlorinated hydrocarbons and heavy metals and occupied only by pollution-tolerant worms. Destruction of shoreline wetlands and disposal of sewage and toxic substances in the Detroit River have reduced habitat and conflict with basic biological processes, including the sustained production of fish and wildlife. Current regulations do not adequately control pollution loadings. However, remedial actions are being formulated by the U.S. and Canada to restore degraded benthic habitats and eliminate discharges of toxic contaminants into the Detroit River.Contribution 738 of the National Fisheries Research Center-Great Lakes, 1451 Green Road, Ann Arbor, MI 48105, U.S.A.  相似文献   

3.
Nine of 10 genera and 119 of approximately 240 species of the Pinaceae occur in China, including 67 endemic species and two endemic genera. In this paper, the distributional maps of all the genera of the Pinaceae are presented (fig. 1-8). The horizontal and vertical distributions of species in each genus are discussed. The analysis of the distribution patterns of the genera indicates that some genera, such as Keteleeria, Tsuga, Pseudotsuga, Cathaya and Pseudolarix, are restricted to the area south of the Qinling Mountains and the Huaihe River, and the others, i. e. Picea, Abies, Larix and Pinus, extend northward to northeastern China. However, all of the genera except Keteleeria and Pinus are not found in very dry areas and tropical mountainous regions of China. The monotypic genera, Cathaya and Pseudolarix, are distributed in eastern and central China. The genus Keteleeria consists of 10 species, 7 of which are concentrated in southern Guizhou, northern Guangxi, southwestern Hunan and easternmost Yunnan. The distribution of the remaining 6 genera shows the maximum concentration in western Sichuan and northwestern Yunnan. (Figs. 2-8). Furthermore, more than third of species of the Pinaceae (37.8%) are also concentrated in western Sichuan and northwestern Yunnan. where a great variety of habitats and different topographic features occur. It is apparent that to conduct our systematic and evolutionary studies on this family in these region is especially needed. The relations between the areal size and the tolerance of species are discussed. The distributions of macrofossils and microfossils of the genera of the Pinaceae ia China are given, and it has been proved that areas of most genera of the family were considerably larger in the past. than at present.  相似文献   

4.
The Hierarchical Taxonomy of Psychopathology (HiTOP) is a scientific effort to address shortcomings of traditional mental disorder diagnoses, which suffer from arbitrary boundaries between psychopathology and normality, frequent disorder co‐occurrence, heterogeneity within disorders, and diagnostic instability. This paper synthesizes evidence on the validity and utility of the thought disorder and detachment spectra of HiTOP. These spectra are composed of symptoms and maladaptive traits currently subsumed within schizophrenia, other psychotic disorders, and schizotypal, paranoid and schizoid personality disorders. Thought disorder ranges from normal reality testing, to maladaptive trait psychoticism, to hallucinations and delusions. Detachment ranges from introversion, to maladaptive detachment, to blunted affect and avolition. Extensive evidence supports the validity of thought disorder and detachment spectra, as each spectrum reflects common genetics, environmental risk factors, childhood antecedents, cognitive abnormalities, neural alterations, biomarkers, and treatment response. Some of these characteristics are specific to one spectrum and others are shared, suggesting the existence of an overarching psychosis superspectrum. Further research is needed to extend this model, such as clarifying whether mania and dissociation belong to thought disorder, and explicating processes that drive development of the spectra and their subdimensions. Compared to traditional diagnoses, the thought disorder and detachment spectra demonstrated substantially improved utility: greater reliability, larger explanatory and predictive power, and higher acceptability to clinicians. Validated measures are available to implement the system in practice. The more informative, reliable and valid characterization of psychosis‐related psychopathology offered by HiTOP can make diagnosis more useful for research and clinical care.  相似文献   

5.
The development of new taxonomical theories and approaches, particularly molecular phylogenetics, has led to the expansion of traditional morphology-based taxonomy into the concept of "integrative taxonomy." Taxonomic knowledge has assumed greater significance in recent years, particularly because of growing concerns over the looming biodiversity crisis. Since its establishment in 1938, the Kunming Institute of Botany (KIB), which is located in Yunnan province in Southwest China, has focused attention on the taxonomy and conservation of the flora of China. For the forthcoming 80th anniversary of KIB, we review the achievements of researchers at KIB and their associates with respect to the taxonomy of land plants, fungi, and lichen. Major taxonomic advances are summarized for families of Calymperaceae, Cryphaeaceae, Lembophyllaceae, Neckeraceae, Polytrichaceae and Pottiaceae of mosses, Pteridaceae and Polypodiaceae of ferns, Taxaceae and Cycadaceae of gymnosperms, Asteraceae, Begoniaceae, Ericaceae, Euphorbiaceae, Gesneriaceae, Lamiaceae, Orchidaceae, Orobanchaceae, Poaceae, Theaceae and Urticaceae of angiosperms, Agaricaceae, Amanitaceae, Boletaceae, Cantharellaceae, Physalacriaceae Russulaceae, Suillaceae and Tuberaceae of fungi, and Ophioparmaceae and Parmeliaceae of lichens. Regarding the future development of taxonomy at KIB, we recommend that taxonomists continue to explore the biodiversity of China, integrate new theories and technologies with traditional taxonomic approaches, and engage in creative monographic work, with support from institutions, funding agencies, and the public.  相似文献   

6.
A key is presented for use in identifying asymmetrically winged fruits (samaras) with either proximal or distal locules. It aids identification based on dispersed fuit morphology and can be used to identify undetermined extant herbarium specimens or fossil fruits to the correct extant family and genus. The 39 genera from 11 families (Aceraceae, Anacardiaceae, Fabaceae, Malpighiaceae, Phytolaccaceae, Polygalaceae, Polygonaceae, Rutaceae, Sapindaceae, Trigoniaceae, Ulmaceae) are distinguished on the basis of wing venation, size of fruit, presence and position of attachment surface, presence and type of subsidiary wings on the ovary wall. ornamentation, size and shape of the ovary, locule position, shape of locule cross section, style position and ornamentation, distinction between ovary wall and wing, and angle of attachment between individual samaras. The developmental origins of some of these features are discussed.  相似文献   

7.
Numbers of species and genera,endemic genera,extant primitive genera,relationship and distribution patterns of presently living Chenopodiaceae(two subfamilies,12 tribes,and 118 genera)are analyzed and compared for eight distributional areas,namely central Asia,Europe,the Mediterranean region,Africa,North America,South America, Australia and East Asia. The Central Asia,where the number of genera and diversity of taxa are greater than in other areas,appears to be the center of distribution of extant Chenopodiaceae.North America and Australia are two secondary centers of distribution. Eurasia has 11 tribes out of the 12,a total of 70 genera of extant chenopodiaceous plants,and it contains the most primitive genera of every tribe. Archiatriplex of Atripliceae,Hablitzia of Hablitzeae,Corispermum of Corispermeae,Camphorosma of Camphorosmaea,Kalidium of Salicornieae,Polecnemum of Polycnemeae,Alexandra of Suaedeae,and Nanophyton of Salsoleae,are all found in Eurasia,The Beteae is an Eurasian endemic tribe,demonstrating the antiquity of the Chenopodiaceae flora of Eurasia.Hence,Eurasia is likely the place of origin of chenopodiaceous plants. The presence of chenopodiaceous plants is correlated with an arid climate.During the Cretaceous Period,most places of the continent of Eurasia were occupied by the ancient precursor to the Mediterranean,the Tethys Sea.At that time the area of the Tethys Sea had a dry and warm climate.Therefore,primitive Chenopodiaceae were likely present on the beaches of this ancient land.This arid climatic condition resulted in differentiation of the tribes Chenopodieae,Atripliceae,Comphorosmeae,Salicornieae,etc.,the main primitive tribes of the subfamily Cyclolobeae. Then following continental drift and the Laurasian and Gondwanan disintegration, the Chenopodiaceae were brought to every continent to propagate and develop, and experience the vicissitudes of climates, forming the main characteristics and distribution patterns of recent continental floras. The tribes Atripliceae, Chenopodieae, Camphorosmeae, and Salicornieae of recent Chenopodiaceae in Eurasia, North America, South America, southern Africa, and Australia all became strongly differentiated. However, Australia and South America, have no genera of Spirolobeae except for a few maritime Suaeda species. The Salsoleae and Suaedeae have not arrived in Australia and South America, which indicates that the subfamily Spirolobeae developed in Eurasia after Australia separated from the ancient South America-Africa continent, and South America had left Africa. The endemic tribe of North America, the tribe Sarcobateae, has a origin different from the tribes Salsoleae and Suaedeae of the subfamily Spirolobeae. Sarcobateae flowers diverged into unisexuality and absence of bractlets. Clearly they originated in North America after North America had left the Eurasian continent. North America and southern Africa have a few species of Salsola, but none of them have become very much differentiated or developed, so they must have arrived through overland migration across ancient continental connections. India has no southern African Chenopodiaceae floristic components except for a few maritime taxa, which shows that when the Indian subcontinent left Africa in the Triassic period, the Chenopodiaceae had not yet developed in Africa. Therefore, the early Cretaceous Period about 120 million years ago, when the ancient Gondwanan and Laurasian continents disintegrated, could have been the time of origin of Chenopodiaceae plants.The Chinese flora of Chenopodiaceae is a part of Chenopodiaceae flora of central Asia. Cornulaca alaschnica was discovered from Gansu, China, showing that the Chinese Chenopodiaceae flora certainly has contact with the Mediterranean Chenopodiaceae flora. The contact of southeastern China with the Australia Chenopodiaceae flora, however, is very weak.  相似文献   

8.
Chemical basis of inflammation-induced carcinogenesis   总被引:11,自引:0,他引:11  
Chronic inflammation induced by biological, chemical, and physical factors has been associated with increased risk of human cancer at various sites. Inflammation activates a variety of inflammatory cells, which induce and activate several oxidant-generating enzymes such as NADPH oxidase, inducible nitric oxide synthase, myeloperoxidase, and eosinophil peroxidase. These enzymes produce high concentrations of diverse free radicals and oxidants including superoxide anion, nitric oxide, nitroxyl, nitrogen dioxide, hydrogen peroxide, hypochlorous acid, and hypobromous acid, which react with each other to generate other more potent reactive oxygen and nitrogen species such as peroxynitrite. These species can damage DNA, RNA, lipids, and proteins by nitration, oxidation, chlorination, and bromination reactions, leading to increased mutations and altered functions of enzymes and proteins (e.g., activation of oncogene products and/or inhibition of tumor-suppressor proteins) and thus contributing to the multistage carcinogenesis process. Appropriate treatment of inflammation should be explored further for chemoprevention of human cancers.  相似文献   

9.
Athyrisinine brachiopods from the Upper Silurian of Russia and the Lower–Middle Devonian of China and north Vietnam include over 70 species belonging to Athyrisina and Parathyrisina ; generic and subfamilial diagnoses are emended. Five genera are considered synonyms of Athyrisina and three of Parathyrisina . A neotype is selected and illustrated for Athyrisina squamosa , the type species of Athyrisina . Four nomina nova , Athyrisina xui , Parathyrisina wani , P. minima , and P. cheni , are suggested as new substitute names for Athyrisina tumida Wang, in Xu et al. 1978 (primary homonymy), Athyrisinoides ganxiensis Wan, in Xu et al. 1978, Parathyrisina minor Zhang, in Zhang and Fu 1983, and Athyrisinoides tudilingensis Chen, 1979 (secondary homonyms) respectively. A new genus, Bruntosina , is described from the Emsian to Eifelian of the Qinling region. A new subfamily, Homeathyridinae, is erected within the Athyrididae with Homeathyris , Pseudohomeospira , and Squamathyris included, revised and their diagnoses emended. Homeathyris incisus sp. nov. is described from the Ludfordian of Novaya Zemlya. Ikella is revised and excluded from the athyrisinins. The origin and dispersal of the homeathyridins and the athyrisinins are discussed.  相似文献   

10.
【目的】筛选特定条件下麦长管蚜Sitobion avenae稳定表达的微小RNA(miRNA)表达分析内参基因。【方法】根据麦长管蚜miRNA Illumina测序结果筛选出miR-10-3p, miR-993, miR-276, miR-275, miR-252a, miR-1, miR-375, pc-15, pc-73和1个常用内参基因U6共10个候选内参基因。利用qRT-PCR测定10个候选内参基因在麦长管蚜有翅蚜和无翅蚜不同发育时期、不同组织以及4种化学药剂(95.1%吡虫啉原药、97.8%噻虫啉原药、95%阿维菌素原药和40%氧乐果乳油)处理无翅蚜中的相对表达量。利用GeNorm, NormFinder, ΔCt法, BestKeeper和RefFinder对10个候选内参基因的表达稳定性进行评价。【结果】qRT-PCR结果表明,在麦长管蚜有翅蚜不同发育阶段、无翅蚜不同发育阶段、有翅蚜和无翅蚜不同组织中和4种药剂处理的无翅蚜中表达量较高的内参基因分别是miR-276, miR-276, miR-10-3p和miR-10-3p;5种方法综合分析得出,在上述4种条件下表达稳定性都较好的内参基因分别是miR-252a, miR-993, miR-275和miR-993。GeNorm软件分析表明不同条件下麦长管蚜内参基因的较佳数目为2,结合RefFinder稳定性综合排序的结果分析可知在有翅蚜不同发育阶段、无翅蚜不同发育阶段、有翅蚜和无翅蚜不同组织中和不同药剂处理无翅蚜中稳定表达的内参基因组合分别是miR-252a和miR-276, miR-993和miR-276, miR-275和miR-10-3p, miR-993和miR-10-3p。【结论】麦长管蚜有翅蚜不同发育阶段、无翅蚜不同发育阶段、有翅蚜和无翅蚜不同组织中和不同药剂处理无翅蚜中内参基因优化组合分别为miR-252a和miR-276, miR-993和miR-276, miR-275和miR-10-3p, miR-993和miR-10-3p。研究结果为麦长管蚜miRNA基因定量表达的研究提供了内参基因选择的依据。  相似文献   

11.
Summary Parasitic flowering plants from 23 genera in 7 families (Convolvulaceae, Lauraceae, Loranthaceae, Orobanchaceae, Santalaceae, Scrophulariaceae and Viscaceae) have been cultured in vitro. These plants include both hemiparasites and holoparasites that parasitize stems and roots of angiosperms and gymnosperms. This review highlights relevant information on each genus with regard to its biology, distribution, host range, and tissue culture procedures. Tissue culture has been used to study aspects of the development, metabolism, reproduction, physiology and nutritional requirements of these plants under controlled conditions. Studies of host-parasite relationships, including potential roles of signals/receptors that influence host development and physiology, and factors influencing seed germination and haustorium formation, have been conducted. The effects of chemicals and herbicides on the physiology and biochemistry of parasite embryo and seedling development have been studied, as well as the influence of inhibitors or stimulants on seed germination. Tissue culture has provided a method for propagation and genetic improvement of plants with commercial value.  相似文献   

12.
ABSTRACT. The hypostome ciliates have been generally classified into two classes, Phyllopharyngea and Nassophorea. The status of Nassophorea and its relationship with Phyllopharyngea is one of the most controversial issues in ciliate systematics. Here we focus on the phylogenetic interrelationships of Nassophorea and Phyllopharyngea based on small subunit ribosomal RNA gene sequences. The three nassophorean subgroups, synhymeniids, microthoracids, and nassulids, each emerged as monophyletic, with synhymeniids as a sister group of Phyllopharyngea, and microthoracids as a sister of the synhymeniids+Phyllopharyngea clade in all phylogenies. The exact placement of the nassulids, however, remains uncertain. Following a detailed analysis of phenotypic characters, we hypothesize that: (1) the Phyllopharyngea could have evolved from synhymeniids, with the further development of their subkinetal microtubules as one of the major events; and (2) the development of monokinetid structures, as well as the reduction and specialization of the cyrtos and cortex, might have occurred during the diversifications of the microthoracids, synhymeniids, and Phyllopharyngea from a common ancestor. Expanding the class Phyllopharyngea to include the synhymeniids as a subclass, and designating a new subclass Subkinetalia n. subcl. for the group comprising cyrtophorians, chonotrichians, rhynchodians, and suctorians, are proposed.  相似文献   

13.
中国刺猬的染色体研究   总被引:1,自引:0,他引:1  
本文采用全血培养和骨髓染色体制片法,对分布于我国南京市郊和济南市郊的刺猬染色体进行了组型、C-带、G-带和银染色的观察分析,并与东欧、西欧两种刺猬比较,它们之间的核型及带型差异显著;又将南京、济南及金清波(1985)报道的河南新乡三地分布的刺猬进行比较,它们的核型及带型也显示出一定差异,这种多态性在分类和进化上有一定的意义。  相似文献   

14.
Epigenetics studies factors related to the organism and environment that modulate inheritance from generation to generation. Molecular epigenetics examines non-coding DNA (ncdDNA) vs. coding DNA (cdDNA), and pertains to every domain of physiology, including immune and brain function. Molecular cartography, including genomics, proteomics, and interactomics, seeks to recognize and to identify the multi-faceted and intricate array of interacting genes and gene products that characterize the function and specialization of each individual cell in the context of cell-cell interaction, tissue, and organ function. Molecular cartography, epigenetics, and chromatin assembly, repair and remodeling (CARR), which, together with the RNA interfering signaling complex (RISC), is responsible for much of the control and regulation of gene expression, intersect.We describe current and ongoing studies aimed to apply these overlapping areas of research, CARR and RISC, to a novel understanding of the immuno-neuropathology of HIV-1 infection, as an example. Taken together, the arguments presented here lead to a novel working hypothesis of molecular immune epigenetics as it pertains to HIV/AIDS, and the immunopathology of HIV-1-infected CD4+ cells. Specifically, we discuss these views in the context of the structure-function relationship of chromatin, the cdDNA/ncdDNA ratio, and possible nucleotide divergence in the untranslated regions (UTRs) of mature mRNA intronic and intergenic DNA sequences, and putative catastrophic consequences for immune surveillance and the preservation of health in HIV/AIDS. Here, we discuss the immunopathology of HIV Infection, with emphasis on CARR in cellular, humoral and molecular immune epigenetics.  相似文献   

15.
Pollen grains of six species of Gnetum , G. parvifolium , G. hainanense , G. luofuense , G. pendulum , G. cleistostachyum and G. montanum , collected from China were examined using light, scanning and transmission electron microscopy. Pollen grains of Gnetum are subspheroidal or irregular-apolar, inaperturate, 11.21–22.44 µm in long axis and 9.34–20.47 µm in short axis. The exine surface is covered with spinules, 0.50(0.30–0.71) µm long spaced on average 1.12(0.81–1.46) µm apart. The exine is about 0.55 µm thick and comprises ectexine and endexine. The ectexine includes a thin tectum and an infratectal granular layer. The tectum protrudes outwards, forming the spinules. The endexine is composed of discontinuous lamellae, with lacunae between lamellae. The pollen grains of Gnetum are compared with those of Ephedra and Welwitschia , and also those of the ANITA Group of angiosperms, including Amborellaceae, Nymphaeales, Illiciales, Trimeniaceae and Austrobaileyaceae. The exine ultrastructures of Gnetum , Ephedra and Welwitschia are quite similar, consisting of tectum, granular layer and lamellated endexine. The exine ultrastructure of Gnetum is also similar to that of Nymphaea colorata (Nymphaeaceae) in the transitional region between the proximal and distal poles, but differs from that of Amborellaceae, Illicium religiosum (Illiciaceae), Schisandra (Schisandraceae), Trimeniaceae and Austrobaileyaceae. This comparison of exine ultrastructure provides new evidence for consideration of the relationship between Gnetum and the ANITA Group.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 415–425.  相似文献   

16.
Here we report the results of a comprehensive biogeochemical monitoring of Rostherne Mere in 1998, including changes in dissolved oxygen, organic carbon and nitrogen, nitrate/nitrite, ammonia, Al, Na, S, K, Mg, Ca, Si, Fe, Mn, orthophosphate, particulate N & P, suspended solids, temperature, pH, chlorophyll-a and zooplankton. The results demonstrated the major influence of primary producers on the overall geochemical cycling of N, P and Si, and suggested that the significance of zooplankton might have been previously underestimated. For major anions and cations, however, the influence of biota on lake water concentrations appeared to be negligible, reflecting the fact that these chemicals were present far in excess of plankton requirements. Thus changes in concentrations of Ca, K, Na, Mg and S were rather limited and must have reflected changes in hydrological and meteorological parameters. K, however, demonstrated a transitional pattern, reflecting some influence of biological uptake. During the stratification period, the slow processes of bacterial decomposition in the hypolimnion gradually released chemicals contained in the materials accumulated in the bottom layer, remarkably increasing the concentrations of dissolved compounds of those elements present in amounts comparable with the pool stored in the sedimenting detritus (e.g. orthophosphate P, ammonia N, Si and DOC). The decomposition also resulted in a drop in the redox potential, followed by partial denitrification and chemical release from the sediments. The hypolimnion of the Mere was confirmed to remain at the stage of Mn release, characterised by accumulation of DOC, orthophosphates, ammonia and initial stages of denitrification. High levels of P released from the sediments during the stratification period suggest that the lake’s recovery after sewage diversion might be further delayed.  相似文献   

17.
The wetlands of 21 countries and territories of the Pacific Islands region are reviewed: American Samoa, Cook Islands, Federated States of Micronesia, Fiji, French Polynesia, Guam, Kiribati, Marshall Islands, Nauru, New Caledonia, Niue, Northern Mariana Islands, Palau, Papua New Guinea, Samoa, Solomon Islands, Tokelau, Tonga, Tuvalu, Vanuatu, and Wallis and Futuna. The regions’ wetlands are classified into seven systems: coral reefs, seagrass beds, mangrove swamps, riverine, lacustrine, freshwater swamp forests and marshes. The diversity of species in each of these groups is at near global maxima at the west of the region, with decline towards the east with increasing isolation, and decreasing island size and age. The community structure is unique in each country, and many have endemic species with the habitat isolation that epitomises this island region. There remain, however, some serious gaps in basic inventory, particularly in freshwater biodiversity. Threats to wetlands include introduced freshwater species, loss of wetlands adjacent to urban growth, downstream effects of mining and land clearance, and over-use of mangrove, seagrass and coral reef resources by predominant subsistence economies that remain in this region. Only five countries are signatories to the Ramsar convention on wetlands, and this only recently with seven sites. Wetland managers have identified the need for community education, baseline surveys and monitoring, better legislation and policy for wetland management, and improved capacity of local communities to allow the wise use of their wetlands.  相似文献   

18.
Mono- and sesquiterpenoids from wood of P. quadrifolia and that of the southwestern form of P. monophylla were analysed by GLC. Concurrently the number of needles per fascicle, the number of resin canals, and the number of abaxial and adaxial stomatal rows towards the tip, in the middle, and towards the base of the needles were determined. The data covered 90 trees from 8 pure populations from southernmost California and northern Baja California and 21 trees from a mixed stand in Baja California.α-Pinene, mycene, α-amorphene, γ-muurolene, germacrene D, and to a very minor extent camphene, β-pinene, limonene, β-phellandrene and β-ylangene percentages could be used for species identification. The number of needles per fascicle, the number of resin canals, and the number of abaxial stomatal rows afforded appreciably sharper identification, however. Statistical treatment of chemical and morphological data from pure stands did not give evidence for introgression of the two species. A definite intermediacy, rather limited in extent, could be demonstrated for the mixed stand, however.  相似文献   

19.
Morphological responses of American cranberry (Vacciniummacrocarpon Ait, Ericaceae) to different light conditions (red,far-red, white light and sunlight) were examined. Root growth and development,stem elongation, leaf enlargement, de-etiolation of stem and leaf, flower budformation, and flowering of American cranberry were measured under each lightcondition and in the dark. It was found that red light promotes development ofroots and leaves, flowering, and de-etiolation of stem and leaf of Americancranberry. Stem elongation and etiolation of stem and leaf were shown infar-redlight and dark. Anthocyanin biosynthesis as phytochemical response in cranberryplants was most sensitive to red light. Estimation of anthocyanin levels indifferent parts of cranberry plant suggested that anthocyanins were presentonlyin red fruit skins, and not in peeled fruits, green fruits, green leaves, greenstems, roots and seeds.  相似文献   

20.
I provide my retrospective and prospective views on adaptations of cave fishes. I emphasize the history of my insights into cave adaptation from 45 years of research using surface, cave-spring, and cave species of amblyopsid fishes. My approach has been to use natural experiments and to always consider multiple hypotheses. To clarify evolutionary adaptations, I show the importance of a broad comparative approach which includes studies of morphology, metabolic physiology, foraging behavior, life history, and ecology. And I show that the most important agents of selection, of darkness and attendant low food supply, are best understood in the context of rigor, variability, and predictability. I also present my insights from what I consider the most insightful contributions on deep-sea fishes. The contributions are those of Marshall in studies of morphology in relation to energy economy of pelagic and benthic species, Childress in studies of physiological and biochemical adaptations with depth for pelagic species, and Koslow in studies on population biology and life history of bathybenthic and benthic sea-mount species. Compared to caves, I suggest that the extremes of metabolic and life history adaptations of deep-sea fish are explained by a longer evolutionary history and a much greater habitat range, food supply, and predation risk. Finally, I take a retrospective view of what we have learned about cave fishes. I discuss possible evolutionary mechanisms that can explain the trends with increasing cave adaptation in amblyopsid fishes, especially progenesis and the pleiotropic effects of the stress resistance syndrome. Finally, based on insights from deep-sea fishes, and emerging new techniques, I suggest what cave fish biologists should do in the future.  相似文献   

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