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1.
Finger pattern types, pattern intensity indices and finger ridge counts in 110 individuals (54 males and 56 females) from Corte in the central area of Corsica (France) were investigated. The comparison of the Corsican qualitative and quantitative digital dermatoglyphics with those from other samples of Mediterranean and European countries show a clearcut difference between Corsicans and Continental Italian populations and a great affinity between Corsicans and Sardinians. These results are regarded as compatible with the interpretation of archaeological, historical and genetic evidence.  相似文献   

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Despite collecting copious amounts of data, wood anatomists rarely perform appropriate statistical analyses, especially in the case of categorical variables. Nevertheless, anatomists have succeeded in identifying strong ecological trends. We show that, with only a slightly more sophisticated analysis, the strength and significance of 'well-known' associations can be quantified, and new associations pinpointed. Using logistic regression to reanalyse the classic Carlquist and Hoekman data set for the southern Californian flora, we show strong support for the notion that true tracheid presence lowers vessel grouping; in contrast, vasicentric tracheids are associated with a diversity of vessel grouping strategies. We show that statistical models can refine anatomical interpretations by identifying unusual species. For example, Fremontodendron californicum and Baccharis salicifolia (=  B. glutinosa ) were identified as unusual in lacking vasicentric tracheids; a consultation of preparations revealed that they are indeed present. For purposes of ecological wood anatomy, anatomical terminology should reflect cell function; we suggest that terminological systems that yield better predictive power in statistical models such as ours are preferable. Finally, we make recommendations ranging from the statistical, e.g. the need to check assumptions and the need for the inclusion of phylogeny, to the biological, e.g. gathering data expressly designed to test functional hypotheses rather than all of the information in standardized lists.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 154 , 331–351.  相似文献   

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Global warming will likely exacerbate the negative effects of limited water availability in the Mediterranean area. The Italian Aleppo pine (Pinus halepensis Mill.) provenances are distributed along the coasts except Otricoli provenance growing in an unusual location between 300 and 1,000 m a. s. l., in Umbria (central Italy). The aim of the present study was to investigate the photosynthetic response to a 28-day-long drought and to a subsequent reestablishment of water availability in Otricoli and North Euboea (Greece) provenances, representing different locations along a rainfall gradient in the natural range of this species. Six-month-old seedlings were used in this experiment since at this age Aleppo pine plants in Mediterranean climate face their first water stress potentially affecting plant survival. Water potential (ψw), net photosynthesis and stomatal conductance decreased during drought in both provenances and showed minimal values 28 days after beginning the treatment (DAT). Otricoli seedlings adjusted ψw gradually as the stress level increased and 21 DAT showed a lower ψw than North Euboea. In contrast, in North Euboea seedlings ψw that was not affected until 21 DAT rapidly dropped to a minimum of −3.81 MPa 28 DAT. At the onset of the stress the intercellular CO2 concentration (C i) was reduced, and the “instrinsic” water-use efficiency (WUEi) was enhanced in both provenances, as stomatal conductance decreased more rapidly than photosynthesis. However, 28 DAT, C i increased and WUEi decreased as stomatal conductance and photosynthesis declined to minimum levels, revealing nonstomatal limitations of photosynthesis. A rapid decrease in PSII maximal photochemical efficiency estimated by chlorophyll (Chl) fluorescence (Fv/Fm) was also observed when the stress became severe. At the final stage of water stress, North Euboea seedlings maintained significantly higher values of Fv/Fm than Otricoli seedlings. Upon rewatering, photosynthesis did not fully recover in Otricoli seedlings (41 DAT), while all other parameters recovered to control levels in both provenances. No drought-induced physiological differences were consistent with the regional climatic features of these two provenances. Our results suggest that phenotypic plasticity in drought response may help Otricoli provenance cope with global warming, but that recurrent drought episode may slow down the primary productivity of this provenance.  相似文献   

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Stable isotopes in tree rings have widely been used for palaeoclimate reconstructions since tree rings record climatic information at annual resolution. However, various wood components or different parts of an annual tree-ring may differ in their isotopic compositions. Thus, sample preparation and subsequent laboratory analysis are crucial for the isotopic signal retained in the final tree-ring isotope series used for climate reconstruction and must therefore be considered for the interpretation of isotope–climate relationships. This study focuses on wood of Corsican Pine trees (Pinus nigra ssp. laricio) as this tree species allows to reconstruct the long-term climate evolution in the western Mediterranean. In a pilot study, we concentrated on methodological issues of sample preparation techniques in order to evaluate isotope records measured on pooled whole tree-ring cellulose and whole tree-ring bulk wood samples. We analysed 80-year long carbon and oxygen chronologies of Corsican Pine trees growing near the upper tree line on Corsica. Carbon and oxygen isotope records of whole tree-ring bulk wood and whole tree-ring cellulose from a pooled sample of 5 trees were correlated with the climate parameters monthly precipitation, temperature and the self-calibrating Palmer Drought Severity Index (sc-PDSI). Results show that the offsets in carbon and oxygen isotopes of bulk wood and cellulose are not constant over time. Both isotopes correlate with climate parameters from late winter and summer. The carbon and oxygen isotope ratios of cellulose are more sensitive to climatic variables than those of bulk wood. The results of this study imply that extraction of cellulose is a pre-requisite for the reconstruction of high-resolution climate records from stable isotope series of P. nigra ssp. laricio.  相似文献   

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In this study, pollen grains and anatomical features of Turkish lilies were investigated under the electron (SEM) and light (LM) microscope. LM and SEM observations showed that the pollen grains are monosulcate, heteropolar, elliptical in polar view and oblate. Numerical results based on combined palynological and anatomical characters were discussed and compared with traditional taxonomic treatments. It was found that the midrib shape, mesophyll type, P/E (polar/equatorial), sulcus length, and lumina width are the most valuable traits in separating the examined taxa. The numerical analysis showed that Lilium candidum L. differs from the rest Turkish Lilium and also confirmed a close relationship between L. szovitsianum Fisch. & Avé-Lall. and L. armenum Miscz. ex Grossh. Also this study is the first report dealing with anatomical and palynological features of all Turkish lilies.  相似文献   

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In northern Sweden breeding males of Tengmalm's owls (Aegolius funereus (L.)) were site tenacious during and between the peaks of the vole (staple food) cycles, but females only during the peaks. Most of these adults shifted nest boxes between successive years. They selected nest boxes randomly in a radius of 3 km. Juveniles, in contrast to site tenacious adults, dispersed outside their natal area. The females moved longer than the males prior to their first breeding. Five adult females were found to be nomadic. One of these nomadic females previously bred site tenaciously as long as food was abundant. Juveniles and adult males were not found to be nomadic. Emigration of adult females and juveniles occurred most frequently when vole populations declined. The breeding population increased sharply and received immigrants suggesting that nomadism may be essential in the population dynamics. Site tenacity and nomadism are discussed in terms of costbenefit to males and females, respectively. Emphasis is on the main functional roles of males (feeding femle and young) and females (incubation).  相似文献   

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《Dendrochronologia》2014,32(4):303-312
Mountain conifers in the Great Basin of North America have provided some of the longest, continuous, and annually resolved paleoclimate records. Climate-growth relationships at the cellular level, which help understand wood formation processes that underlie dendroclimatic reconstructions, are at present largely unexplored in the Great Basin. We analyzed 42 trees located in the Snake Range (eastern Nevada, USA) at three sites along an elevation gradient. Sampled species included white fir (Abies concolor), Douglas fir (Pseudotsuga menziesii), limber pine (Pinus flexilis), bristlecone pine (Pinus longaeva), and Engelmann spruce (Picea engelmannii). Wood anatomical features were quantified for two consecutive years, 2011 and 2012. Lumen area, cell wall thickness, lumen diameter, and wall-to-cell ratio were measured for the total ring as well as for earlywood and latewood. Mean standardized tracheidograms highlighted differences between 2011 and 2012, in particular concerning lumen area and wall-to-cell ratio. Most annual variation was due to earlywood, rather than latewood. Anatomical parameters of limber pine, the only species that could be tested at both the montane and subalpine sites, varied with elevation. Principal component analysis showed that the main axis of variability was related to dimensional parameters (e.g. lumen area), which reflected differences in water availability.  相似文献   

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In order to establish the general environmental conditions under which the plants of the El Cien Formation grew during the Miocene, wood anatomical features from several extant ecological categories (southern California flora) and communities (Brazil, Mexico and Suriname) as well as those of the El Cien paleocommunity were analysed using different statistical approaches. We find a significant correlation between 42 characters of 199 species and 11 climate variables which suggests a close association of wood characters with temperature, whereas characters such as diameter, frequency, and grouping of vessels are more closely related to evaporation. The expression of various wood characters depends on more than one climate variable. There are no doubts regarding the tropical affiliation of the El Cien fossil flora but water availability and seasonality of the system are less clear. Principal component and cluster analyses of two different datasets (423 species, 9 characters and 223 species, 32 characters) suggest that the physiognomy of the fossil assemblage of El Cien was highly efficient in water transport, but also highly vulnerable to embolisms. Characters such as vessel diameter, frequency and grouping suggest proximity to a tropical rain forest, whereas the proportion of ring semi ring porous woods brings the El Cien paleoflora closer to forests with slightly xeromorphic physiognomy, probably a tropical deciduous or semi-deciduous forest. This condition is paralleled with the taxonomic composition of the El Cien fossil plants since their Nearest Living Relatives (NLR) can be referred to both humid or more (seasonally) dry environments. Derived regression analysis models suggest that the paleoflora prospered under conditions with an evaporation regime similar to that of the tropical rain forest.  相似文献   

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The composition of solid residues from hydrolysis reactions of loblolly pine wood with dilute mineral acids is analyzed by 13C Cross Polarization Magic Angle Spinning (CP MAS) NMR spectroscopy. Using this method, the carbohydrate and lignin fractions are quantified in less than 3 h as compared to over a day using wet chemical methods. In addition to the quantitative information, 13C CP MAS NMR spectroscopy provides information on the formation of additional extractives and pseudo lignin from the carbohydrates. Being a non-destructive technique, NMR spectroscopy provides unambiguous evidence of the presence of side reactions and products, which is a clear advantage over the wet chemical analytical methods. Quantitative results from NMR spectroscopy and proximate analysis are compared for the residues from hydrolysis of loblolly pine wood under 13 different conditions; samples were treated either at 150 °C or 200 °C in the presence of various acids (HCl, H2SO4, H3PO4, HNO3 and TFA) or water. The lignin content determined by both methods differed on averaged by 2.9 wt% resulting in a standard deviation of 3.5 wt%. It is shown that solid degradation products are formed from saccharide precursors under harsh reaction conditions. These degradation reactions limit the total possible yield of monosaccharides from any subsequent reaction.  相似文献   

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《法国昆虫学会纪事》2012,48(6):497-508
Summary

During a one-year survey of the Auchenorrhyncha fauna in a maquis habitat of the Ajaccio region (Corsica), 37 species were listed including three alien species recorded in Europe in the last decades. The standard 658 bp mitochondrial COI barcode was obtained for 32 species, including 14 species never previously barcoded. Neighbor-joining analyses confirmed the delineation for all the species. However, comparisons with available sequences from mainland Europe showed that four species presented a significant intraspecific divergence (>3%), whereas a reduced interspecific divergence was found for another set of species. Complementary studies may therefore be necessary to better assess their taxonomic levels. Three species – Euscelis lineolata Brullé, 1832 (Cicadellidae), Philaenus spumarius (Linnaeus, 1758) (Aphrophoridae) and Latilica maculipes (Melichar, 1906) (Issidae) – accounted for up to 74.3% of the total insects collected. Although taxonomic interpretations using restricted sampling and COI sequences alone are not robust, the proportion of new sequences highlight the global lack of knowledge about the Auchenorrhyncha as a whole and the potentially presence of cryptic taxa in different clades.  相似文献   

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To genetically reconstruct the demographic history of the human population of Corsica (western Mediterranean), we analyzed the variability at eight autosomal STR loci (FES, VWA, CSF1PO, TH01, F13A1, TPOX, CD4, and D3S1358) in a sample of 179 native blood donors from 4 out of the 5 administrative districts. The main line of genetic discontinuity inferred from the spatial distribution of STR variability overlapped the linguistic and geographic boundaries. In the innermost areas (Corte district) several estimators had larger stochastic effects on allele frequencies. Genetic distance measures underlying different evolutionary models all pointed to a higher variability within Corsicans than within the rest of the Mediterranean reference populations. All Corsican subsamples showed the highest distance with a pooled sample from central Sardinia, thus making recent gene flow between the two neighboring islands unlikely. Hierarchical AMOVA and distance-based multivariate genetic spaces stressed the closeness of Tuscan and Corsican frequency distributions, which could reflect peopling events with different time depths. Anyway, estimated separation times well support the linguistic hypothesis that Neolithic/Chalcolithic events have been far more important than Paleolithic or historical processes in the shaping of present Corsican variability.  相似文献   

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During the 2001–2002 hydrological cycle, 8,000 tons P year−1 (44% as particulate phosphorus) originating from the Seine basin entered the Seine estuary. P content in suspended sediments (SS) is 2.9 g P kg−1 (80% as inorganic form) at Poses (the upstream limit of the Seine estuary). During the transfer from Poses to Caudebec (the limit of saline water intrusion), Particulate Inorganic Phosphorus (PIP) in SS decreases by 40% whereas Particulate Organic Phosphorus (POP) remains stable. This decrease is explained as the result of (i) a dilution by SS poorer in P, originating from storage zones (mudflats) within the estuary, and (ii) a loss of P by sedimentation, especially in the Rouen harbour where 15% to 20% of SS are yearly trapped and extracted. Downstream, in the turbidity maximum of the estuary, P content in SS is twice as low as at Poses (1.5 g P kg−1, 70% as inorganic form). PIP content is fairly homogeneous both vertically and throughout an annual survey. On the other hand, POP varies by season. Higher POP content is observed during vernal period with phytoplankton accumulation. In a salinity gradient from 0 to 30 (PSS78), PIP content further decreases by 30%. POP does not vary much in this gradient, leading to the assumption that PIP is submitted to desorption in response to the dilution by marine waters (poor in orthophosphates). Using 32P isotopic method, we establish a mathematical formulation of P exchangeable between the suspended solid and water phases of the Seine estuary. Particulate P in the turbidity maximum zone is shown to represent a possible source of dissolved P, available for algal growth in the Seine Bight. Instead of playing a role of nutrient retention, the turbidity maximum zone of the Seine estuary could favour coastal eutrophication.  相似文献   

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不同干扰措施对松材线虫入侵松林内物种多样性的影响   总被引:1,自引:0,他引:1  
经野外调查发现:松材线虫入侵松林后,对原先林型相同的两块染病松林而言,经过人为伐除和保留受害木这两种干扰措施后,任其自然恢复更新,后恢复的林型会大不相同,即对受害木采取不同的干扰措施会对染病松林内林下植被的更新产生不同的影响.基于以上出发点,以松材线虫入侵后采取不同伐除干扰措施的2个马尾松受害群落为研究对象,针对受害木移除和保留两种处理方式,选择α多样性指数函数Rényi指数为测量单位,探讨了不同受害木处理方式下植物多样性的变化规律.结果表明:受害木及时移走的松林内林下灌草多样性比受害木保留的要高.  相似文献   

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【目的】本研究旨在建立携带与未携带松材线虫Bursaphelenchus xylophilus的松墨天牛Monochamus alternatus成虫各组织的转录组数据库,揭示松墨天牛对松材线虫响应的转录组整体表达特征。【方法】以携带和未携带松材线虫的松墨天牛成虫的表皮、气管和脂肪体为材料,采用Illumina HiSeqTM 2000测序平台开展转录组测序,利用Trinity软件对RNA-Seq数据进行从头组装,利用NCBI数据库进行基因注释。通过DEG-Seq分析携带和未携带松材线虫的松墨天牛成虫中的差异表达基因,对上调表达基因进行GO和KEGG代谢途径富集分析,并通过实时荧光定量PCR技术对部分差异表达的基因包括ENV, CDK1, HSP70-C, HSP70, HSP75, DUO, PABPN1和IGFP基因的表达水平进行验证。【结果】测序过滤后共获得55 059条单基因簇(unigene),平均长度为1 536 bp。将unigene与数据库中的序列进行BLASTX比对,成功注释24 354条unigenes,其中4 022条unigene在GO数据...  相似文献   

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Many buildings are being restored in the city of Aix-en-Provence, southeastern France and allowed systematic dendrochronological analyses. 144 fir timbers (Abies alba Mill.) were examined and dated between 1303 and 1933. They highlight three felling phases (Medieval period, 17th-18th century, and 19th century). The best documented one corresponds to the 17th-18th centuries and coincides with significant building activity connected to the status of Aix, which is the parliamentary capital of Provence. Around Aix-en-Provence, it is difficult to find timbers with good dimensions. Our results show that timbers were transported from the Alps to Aix’s buildings. Potential testimonies of this timber trade have been found, such as raft assemblage marks, and carved signs and letters. A dendroprovenancing case study shows that between 1810 and 1890, some of Aix’s timbers could have come from the Northern French Alps or the Verdon-Durance region. Finally, the lack of timbers with good dimension and the difficulties of timber supply contributed to the development of reuse economy and technical innovation. These results are the foundation of a future well-established dendroprovenancing approach in the Southern Alps.  相似文献   

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Cellulases are pathogenic substances suspected to be responsible for the development of the early symptoms of nematode disease. The pine wood nematode, Bursaphelenchus xylophilus (Parasitaphelenchidae), is the causal agent of pine wilt disease, which kills millions of pine trees. We used RNA interference (RNAi), a reverse genetic tool, to analyze the function of the endo-β-1,4-glucanase gene of B. xylophilus, which causes the most serious forest tree disease in China and the rest of eastern Asia. Silencing of this gene was detected through real-time PCR and cellulase activity assays after soaking for 24 h in dsRNA. The cellulase gene silencing effects differed among various siRNAs. The propagation and dispersal ability of these nematodes decreased when the endo-β-1,4-glucanase gene was silenced. It is important to select an effective siRNA before performing an RNAi test.  相似文献   

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