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1.
The germination response to NaCl treatments has been studied in Melilotus seed populations collected from saline and non-saline soils in the Guadalquivir delta. The rank orders for salt tolerance and seed weight were the same in the threeMelilotus species living in this area:Melilotus messanensis>M. segetalis>M. indica. Within the species, differences in germination response to salinity were found inM. indica (6 populations) andM. segetalis (8 populations). The relationship between salt tolerance during germination and salinity of maternal habitat is discussed.  相似文献   

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3.
This paper presents the results of a karyological analysis of 14 species ofAlchemilla L. collected from SW Europe (Spain and French Pyrenees). About 75% of the analyzed species have chromosome numbers 2n = 95–136. A few species have lower chromosome numbers. The chromosome numbers of 13 species are presented for the first time.  相似文献   

4.
 Seeds of six endemic species and two circumpolar species were collected from several sites on Kerguelen and tested for germination between 5 and 25°C on thermogradient bars. Pringlea antiscorbutica and Colobanthus kerguelensis had a near 100% viability with an initial germination temperature of ca. 24°C. Colobanthus attained nearly 100% viability from 5 to 25°C whereas Pringlea germination declined markedly below 20°C. In Poa kerguelensis and P. cookii germination was poor and varied between sites. The three Ranunculus spp. showed various degrees of dormancy. In Lyallia kerguelensis, although the seed appeared mature, a variety of treatments could only partly release an apparently deep dormancy. These data are discussed with respect to field observations on reproduction from seed. Received: 1 February 1996/Accepted; 28 April 1996  相似文献   

5.
The investigated species are Lycopersicon cheesmanii s.str., L. cheesmanii var. minor, L. chilense, L. hirsutum s. str., L. hirsuturn f. glabratum , L. parviflorum, L. chmielewskii, L. peruvianum s. str., L. peruvianum var. humifusum, L. pimpinellifolium and Solanum penellii . Wound-emitted leaf volatiles isolated and concentrated by adsorption on Tenax GC were separated by capillary gas chromatography. The different species produce different and rather broad patterns of volatiles especially compared to a modem tomato cultivar. There is also a considerable difference between varieties of the same species. When more than one accession was investigated, the results indicated a chemotype differentiation. The chemotypes are in some cases specialized with one or a few quantitatively dominating main components. L. hirsutum emits the greatest number of components. Three accessions had α-zingeberene, α-santalene, and limonene as main component, respectively. The investigated accession of L. hirsutum f. glabratum has 2-undecanone as main component, instead of 2-tride-canone previously identified as main component in another accession. Both compounds are natural insecticides. The results illustrate the need for basic knowledge of the chemical characters in the ancestors of cultivated plants.  相似文献   

6.
Pseudobombax tomentosum and P. longiflorum are common trees in the Cerrado region, but the former species is more common in forest edges while the later is present in open cerrado areas. This work aimed to investigate differences in seed germination and seedling growth in these species, from seed collected from Cerrado areas in Central Brazil. For this, a seed germination experiment was designed and included four replicates with 25 seeds per species; seeds were randomly distributed in the germination chamber. To evaluate initial seedling growth, seedlings height was measured up to 67 days after seedling emergence; besides, some of these seedlings were grown for biomass evaluation during nine months. Results showed that seeds of the two species had the same germinability (near 100%) and mean germination time (ca. 12 days). However, P. longiflorum showed a more spread seed germination through time, with higher values of coefficient of variation in germination time and uncertainty index; and lower values of synchronization than P. tomentosum. The two species showed basically the same growth pattern, but lower values for height of apical meristem, diameter of underground structures (mostly roots), dry mass of shoots, underground structure and total mass of seedlings in P. tomentosum were obtained, compared to P. longiflorum. Both species allocated more dry mass to underground structures in detriment of shoot. This probably allows resprouting behavior which prevents hydric stress and detrimental fire action typical of the open Cerrado areas.  相似文献   

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8.
During summer and autumn 1988, benthic fluxes of nutrients and oxygen were measured in the Bay of Cadiz. The study was carried out using benthic chambers and in addition by determining gradients of nutrient concentration in interstitial water. Fluxes ranged between 13.5–24.3, 3.4–7.8, 6.1–28.4 and (− 99.4)−(− 188.5) mmol m− 2 d−1 for NH4 + , o-P, SiO2 and O2 respectively. These values are far higher than those reported by other authors for locations at similar latitudes. The stoichiometry of O, N and P transference suggest that benthic degradation of principally allochthonous organic matter takes place mainly through anaerobic pathways.  相似文献   

9.
In this study, the pollen morphology of 11 taxa belonging to Atossa (Alef.) Asch. & Graebner, Hypechusa (Alef.) Asch. & Graebner, Peregrinae Kupicha, Wiggersia (Alef.) Maxted, Vicia L. and Narbonensis (Radzhi) Maxted sections of the genus Vicia L. subgenus Vicia (Fabeae, Fabaceae) naturally growing in Turkey has been studied using Light Microscopy (LM) and Scanning Electron Microscopy (SEM) to evaluate the taxonomic relevance of pollen characters. Twelve morphometric characters are analysed with one-way analysis of variance and Tukey’s honestly significant difference test for multiple comparisons. Of the taxa studied V. narbonensis var. narbonensis (sect. Narbonensis) has the largest pollen grains (P = 51.98 μm × E = 30.52 μm) and V. lathyroides (sect. Wiggersia) has the smallest pollen grains (P = 27.71 μm × E = 20.14 μm). The pollen grains are subprolate to perprolate (P/E = 1.16–2.11), but the prolate shape occurs in the majority of the taxa. The regular pollen grains of all taxa are trizonocolporate, isopolar, and released in monads. Ornamentation of the mesocolpium is psilate-perforate in V. lathyroides (sect. Wiggersia), reticulate-rugulate in V. narbonensis var. narbonensis (sect. Narbonensis), (micro)reticulate in V. sericocarpa var. sericocarpa (sect. Hypechusa), V. sativa subsp. sativa (sect. Vicia) and V. grandiflora var. grandiflora (sect. Vicia), and reticulate-perforate in the remaining taxa. The apocolpium and colpus area are psilate or perforate in all taxa except V. sericocarpa var. sericocarpa (sect. Hypechusa) and V. sativa subsp. sativa (sect. Vicia), which exhibit the obscurely reticulate-perforate pattern. Several palynological features have taxonomic importance in sectional level: polar axis, equatorial diameter, pollen shape (P/E ratio), colpus length, colpus width, size of pori, porus length/width ratio, lumina diameter, muri thickness and ornamentation. The results also indicate that pollen characters can be useful in distinguishing the examined taxa.  相似文献   

10.
Teucrium pumilum L., T. lepicephalum Pau, T. libanitis Schreber, T. turredanum Losa & Rivas Goday, and T. carolipaui Vicioso ex Pau (Labiatae) constitute an aggregate included in the Pumilum subsection (Polium section). These species are endemic and geographically restricted to central and south-eastern Spain. They grow under different climatic conditions and have different edaphic requirements, particularly the gypsum and lime affinities. The effects of some ecological factors (i.e. edaphic and climatic factors) on the germination parameters of these Teucrium species were investigated. The species under study differed in their germination behaviour. The majority of the germination parameters appeared more correlated to edaphic than to climatic factors and particularly to the water availability in the soil. The calcicolous T. carolipaui, which grows in the driest habitat, had a more rapid germination than the gypsophilous species. This could be due to the existence of a narrower optimal germination period for T. carolipaui. The different germination requirements of these species of Teucrium are important results to be considered in conservation programs of these endemic and endangered taxa. Section Editor: H. Lambers  相似文献   

11.
To illustrate the effects of domestication on wild pepper, we compared the seed micromorphology and germination characteristics of two wild pepper strains and their corresponding cultivars. The results showed that compared to their corresponding cultivars, wild pepper seeds are significantly smaller, have more groove and ridges on the surface, higher water imbibition rate, higher germination rate and higher α-amylase activity, and digest starch granules faster. The results indicate that the smaller wild seeds are easier to spread; more grooves and ridges on the surface and higher hilum ratio benefit their water imbibition, and rapid decomposition of starch granules and higher α-amylase activity are in favor to germination. By contrast, increased seed size will lead to a reduced germination rate and decreased adaptive ability to water environmental change. Thus, seed size is the result of natural and artificial selection, and whether larger seeds of various pepper cultivars are meaningful in evolution is debatable.  相似文献   

12.
Located on the Iberian Mediterranean coast, El Collado is an open-air site where a rescue excavation was conducted over two seasons in 1987 and 1988. The archaeological work excavated a surface area of 143m2 where 14 burials were discovered, providing skeletal remains from 15 individuals. We have obtained AMS dates for 10 of the 15 individuals by means of the direct dating of human bones. The ranges of the probability distribution of the calibrated dates suggest that the cemetery was used during a long period of time (781–1020 years at a probability of 95.4%). The new dates consequently set back the chrono-cultural attribution of the cemetery from the initial proposal of Late Mesolithic to an older date in the Early Mesolithic. Therefore, El Collado becomes the oldest known cemetery in the Iberian Peninsula, earlier than the numerous Mesolithic funerary contexts documented on the Atlantic façade such as the Portuguese shell-middens in the Muge and Sado Estuaries or the funerary sites on the northern Iberian coast.  相似文献   

13.
These studies investigated the effects of somatostatin on gastric motility in the rainbow trout. Two experimental models were used, the isolated vascularly-perfused stomach and isolated strips of gastrointestinal smooth muscle. Both models demonstrated that somatostatin can inhibit gastrointestinal motility and may therefore modulate gastric emptying in fish.
In the vascularly-perfused stomach, somatostatin (10–1000 n m ) decreased maximum and baseline intragastric pressure by 10–20% in the presence of stimulatory doses of carbachol or 5-hydroxytryptamine. In addition, somatostatin (1 μ m ) inhibited by 50% the magnitude of spontaneous contractions generated by distension. Somatostatin had little effect on the pressure gradient or contractile frequency. These results suggest that somatostatin may negatively modulate gastric emptying in the rainbow trout.
In isolated gastric smooth muscle strips, somatostatin (100 pmol) inhibited tension stimulated by carbachol (circular orientation of muscle) or 5-hydroxytryptamine (longitudinal orientation). These results correlated with those observed in the vascularly perfused stomach preparation. Somatostatin also decreased tension stimulated by carbachol and 5-hydroxytryptamine in intestinal smooth muscle strips, suggesting that under some conditions somatostatin could increase gastric emptying rate by relaxing intestinal musculature.  相似文献   

14.
The Orce region has one of the best late Pliocene and early Pleistocene continental paleobiological records of Europe. It is situated in the northeastern sector of the intramontane Guadix-Baza Basin (Granada, Andalusia, southern Spain). Here we describe a new fossil hominin tooth from the site of Barranco León, dated between 1.02 and 1.73 Ma (millions of years ago) by Electron Spin Resonance (ESR), which, in combination with paleomagnetic and biochronologic data, is estimated to be close to 1.4 Ma. While the range of dates obtained from these various methods overlaps with those published for the Sima del Elefante hominin locality (1.2 Ma), the overwhelming majority of evidence points to an older age. Thus, at the moment, the Barranco León hominin is the oldest from Western Europe.  相似文献   

15.
Seed morphology in Veronica L. (Scrophulariaceae) from south-west Spain   总被引:1,自引:0,他引:1  
Seeds of 12 species of Veronica from south-west Spain were examined with the scanning electron microscope and stereomicroscope. Based on seed shape, colour, cell shape and surface ornamentation, seven morphological types are recognized. Seeds of the different types are described, illustrated and compared. The distribution of seed types among taxa is given. A key to distinguish the different species or groups of species is provided.  相似文献   

16.
Abstract

NATURA-2000, the ecological network of protected areas in the European Union that has been included in the Croatian legislation, defines Community important plant species with imperative on their conservation ex/in situ. In the Botanical Garden of the Faculty of Science, University of Zagreb, five NATURA-species have been selected as research subjects for germination study to shed light on the topic of their seed ecology and consequently advance their conservation efforts: Degenia velebitica, Scilla litardierei, Klasea lycopifolia, Ligularia sibirica and Genista holopetala. The freshly matured seeds of each species were exposed to cold or warm stratification in duration of four to sixteen weeks, and their germination was investigated through different regimes of incubation parameters, i.e. illumination (light/dark) and temperature (5, 15/6, 23?°C). All species had higher germination values after cold stratification, with the exception of G. holopetala. We concluded that D. velebitica, K. lycopifolia and presumably L. sibirica seeds has non-deep physiological dormancy while S. litardierei has deep complex morphophysiological dormancy and G. holopetala has physical dormancy. The observed patterns in seeds’ behaviour are consistent with the conditions in their natural habitats in Croatia and the knowledge of these patterns is vital for successful conservation strategies in the future.  相似文献   

17.
18.
North Spain (Burgos) wild mammals ectoparasites   总被引:1,自引:0,他引:1  
Twenty-seven species of arthropods were collected from 105 wild mammals, six wolves Canis lupus (Linnaeus, 1758) included. A total of 87 animals (82.8%) harboured some ectoparasites. Ticks were found in 60% of the samples, fleas in 51.4%, chewing-lice in 3.8%, and others (Mesostigmata and hippoboscids) in 3.8%. Moreover, 42.5% were single infestation and 57.5% mixed. Some of the species were new records for a host in spanish country such as Trichodectes canis (De Géer, 1778), Ixodes trianguliceps (Birula, 1895), Ceratophyllus (Monopsyllus) S. sciurorum (Schrank, 1803) and Paraceras melis melis (Walker, 1856) on several mammals. Two species were new records for Spain: Chaetopsylla matina (Jordan, 1925) and Archaeopsylla erinacei erinacei (Bouché, 1835).  相似文献   

19.
Figueroa  Javier A. 《Plant Ecology》2003,166(2):227-240
Canopy gap and chilling requirements for seed germination were assessed in 61 and 44 species, respectively, in the temperate rain forest of southern Chile. Germination assays within canopy gap and understorey were carried out under natural conditions. Germination tests in cold stratified and non-stratified seeds were performed under laboratory conditions. Seeds were collected of common trees, shrubs, vines and perennial herbs of forests in southern Chile. Final percent germination was significantly enhanced under canopy gap conditions in 19 species, and significantly reduced in 11 species. Germination proved indifferent under gap vs. understorey conditions in half the species tested. Cold stratification affected germination in 11 species: significantly increasing final germination of four species, and significantly decreasing final percent germination of seven species. A Principal Components Analysis (PCA) was applied with the purpose of identifying groups of species with similar germination strategies. Four attributes were included in the PCA: final germination percentage in canopy gap, germination rate in the laboratory, and gap-and chilling-dependency indices (EGAP and STRAT, respectively). The first axis separated species mainly on EGAP variation while the second axis separated them mainly according to STRAT variation; the two axes together explaining 73% of the among-species variation. A small group of trees and vines germinating best in the understorey and neutral to chilling could clearly be distinguished from the remaining species analyzed. Multifactorial ANOVAs were used for evaluating the combined effect of successional status, seed mass, dispersal period, life form, phylogenetic categories, and dispersal syndrome on EGAP and STRAT variation. The EGAP value of secondary successional species proved significantly greater than that of primary successional species and species with endozoochorous seed dispersal were significantly less dependent on chilling (according to STRAT values) compared to species with mainly wind-dispersed seeds. The possible implications of these results for seedling establishment are discussed. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

20.
The genus Bartonella was detected by PCR in 5.7% (12/212) of wild carnivores from Northern Spain. Based on hybridization and sequence analyses, Bartonella henselae was identified in a wildcat (Felis silvestris), Bartonella rochalimae in a red fox (Vulpes vulpes) and in a wolf (Canis lupus), and Bartonella sp. in badgers (Meles meles).  相似文献   

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