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111.
Stijn Van Slycken Nele Witters Linda Meiresonne Erik Meers Ann Ruttens Pierre Van Peteghem 《International journal of phytoremediation》2013,15(7):677-689
Short rotation coppice (SRC) of willow and poplar might be a promising phytoremediation option since it uses fast growing, high biomass producing tree species with often a sufficient metal uptake. This study evaluates growth, metal uptake and extraction potentials of eight willow clones (Belders, Belgisch Rood, Christina, Inger, Jorr, Loden, Tora and Zwarte Driebast) on a metal-contaminated agricultural soil, with total cadmium (Cd) and zinc (Zn) concentrations of 6.5 ± 0.8 and 377 ± 69 mg kg?1 soil, respectively. Although, during the first cycle, on average generally low productivity levels (3.7 ton DM (dry matter) ha?1 y?1) were obtained on this sandy soil, certain clones exhibited quite acceptable productivity levels (e.g. Zwarte Driebast 12.5 ton DM ha?1 y?1). Even at low biomass productivity levels, SRC of willow showed promising removal potentials of 72 g Cd and 2.0 kg Zn ha?1 y?1, which is much higher than e.g. energy maize or rapeseed grown on the same soil. Cd and Zn removal can be increased by 40% if leaves are harvested as well. Nevertheless, nowadays the wood price remains the most critical factor in order to implement SRC as an acceptable, economically feasible alternative crop on metal-contaminated agricultural soils. 相似文献
112.
Male, female, pupa, larva and egg of a new genus and species of Gracillariidae (Gracillariinae), Spinivalva gaucha Moreira and Vargas from southern Brazil are described and illustrated with the aid of optical and scanning electron microscopy. A preliminary analysis of mitochondrial DNA sequences including members of related lineages is also provided. The immature stages are associated with Passiflora actinia, Passiflora misera and Passiflora suberosa (Passifloraceae), and build mines on the adaxial leaf surface. Initially the mines are serpentine in shape, but later in larval ontogeny become a blotch type. Although the larvae are hypermetamorphic as in other Gracillariidae, there is no sap-feeding instar in Spinivalva gaucha; the larva feeds on the palisade parenchyma, thus producing granular frass during all instars. Pupation occurs outside the mine; prior to pupating, the larva excretes numerous bubbles that are placed in rows on the lateral margins of the cocoon external surface. This is the second genus of gracillariid moth described for the Atlantic Rain Forest, and the second gracillariid species known to be associated with Passifloraceae. 相似文献
113.
The latifrons species-group (=Brachycallimerus
sensu Chapin 1924, Corporaal 1950; = flavofasciatus-group sensu Kolibáč 1998) of Callimerus Gorham is redefined and revised. Five species are recognized including one new species Callimerus cacuminis Yang & Yang sp. n. (type locality: Yunnan, China). Callimerus flavofasciatus Schenkling, 1902 is newly synonymized with Callimerus latifrons Gorham, 1876. Callimerus trifasciatus Schenkling, 1899a is transferred to the genus Corynommadius Schenkling, 1899a. Callimerus gorhami Corporaal, 1949 and Callimerus pallidus Gorham, 1892 are excluded from the latifrons species-group (their assignment to a species-group will be dealt with in a subsequent paper). A key to species of the latifrons species-group is given and habitus of each type specimen, male terminalia, and other diagnostic characters are illustrated. 相似文献
114.
115.
Palpilongus
gen. n. is herein described for one species – Palpilongus bifurcus
sp. n., from Costa Rica, based on male and females. The striking morphological characters of the species – palpus very long, about as long as prementum; upper calypter truncate and very short and setae of male sternite 5 bifurcated, confirm that this new species is also a new genus in the tribe Coenosiini. Male and female terminalia were dissected and illustrated. 相似文献
116.
Recent Quaternary geological and climate events have shaped the evolutionary histories of plant species in the Mediterranean basin, one of the most important hotspots of biodiversity. Genetic analyses of the western Mediterranean Cheirolophus intybaceus s.l. (Asteraceae) based on AFLP were conducted to establish the relationships between its close species and populations, to reconstruct the phylogeography of the group and to analyse potential unidirectional versus bidirectional dispersals between the Ibero‐Provençal belt and the Balearic Islands. AFLP data revealed two main genetic groups, one constituted by the Balearic populations and Garraf (NE Iberia) and the other formed by the remaining mainland populations that were further sub‐structured into two geographically separated subgroups (SE + E Iberia and NE Iberia + SW France). Genetic diversity and spatial structure analyses suggested a mid‐Pleistocene scenario for the origin of C. intybaceus in southern Iberia, followed by dispersal to the north and a single colonisation event of the Balearic archipelago from the near Dianic NE Iberian area. This hypothesis was supported by paleogeographic data, which showed the existence of terrestrial connections between the continent and the islands during the Middle–Late Pleistocene marine regressions, whereas the more recent single back‐colonisation of the mainland from Mallorca might be explained by several hypotheses, such as long‐distance dispersal mediated by migratory marine birds or sea currents. 相似文献
117.
Elisabet Safont Teresa Vegas-vilarrúbia Valentí Rull Bruce K. Holst Otto Huber Shingo Nozawa 《分类学与生物多样性》2013,11(4):327-344
The Guayana Highlands (GH) constitute a highly diverse, but relatively poorly studied Neotropical biome, comprised of ~50 flat-topped mountain summits (called tepuis). Previous studies based on warming forecasts for the region suggested that an upward displacement of environmental conditions of 500–700 m could occur by 2100, potentially resulting in the extinction of c. 50% of its endemic flora due to total habitat loss. To assess the ecological responses of the species to climate change, and select the appropriate conservation measures, long-term monitoring of the GH plant communities will be necessary. In this study, the baseline state for future comparisons was established for the best explored tepui in terms of its flora, Roraima-tepui (2810 m), through a floristic characterization of its different vegetation types. We also identified the environmental gradients underlying the major plant communities, and assessed the effects of human activities on the chemistry of soils and water at three field camps. Our results yielded five main community types: three meadows, one shrubland, and one forest, with their corresponding diagnostic species. The herbaceous communities were mainly influenced by the presence of flat sandy soils, with varying flooding capacity. Shrublands and forests were characterized by irregular organic soils with very low pH. Finally, pH values below 3 were measured on an organic soil of a field camp, although further studies will be necessary to attribute this deviation to human activities. 相似文献
118.
119.
Joseph Woodring 《Physiological Entomology》2020,45(1):89-94
In all developmental stages, the phasmid Peruphasma schultei (Conle & Hennemann, 2005) is an obligate herbivore, whereas the mantid Hierodula membranacea (Burmeister, 1838) is an obligatory carnivore. In P. schultei, the luminal activity of all enzymes is approxximately 50% in the crop and 50% in the midgut, which corresponds to the approximate 50 : 50 ratio of volumes of these two regions. These ratios would be expected in insects with a constant feeding rate on an unvaried diet. The enzyme activity and volume ratios in Hierodula membranacea vary considerably because of the irregular feeding habits. These differences in activity ratios between phasmids and mantids are not associated with the obligate phytophagous or carnivorous diet. The ratio of membrane bound to luminal aminopeptidases and disaccharidases in the midgut of both species are not significantly different and are within the normal range of other paurometabolous insects. Cellobiase and other plant cell wall digesting enzymes, laminarinase and cellobiase, are present in the phasmid but totally lacking in the mantid. The obligate carnivorous feeding habits of mantids could represent a selective factor leading to the loss of the ability to produce β-glucanases. Chitinase is a moulting enzyme in all insects, whereas, in H. membranacea, chitinase also occurs as a luminal digestive enzyme. This modified enzyme function requires production and secretion in another tissue, namely the midgut. 相似文献
120.
Rolando Guadarrama-Ponce Armando Aranda-Anzaldo 《Journal of cellular biochemistry》2020,121(3):2209-2224
Common fragile sites (CFSs) correspond to chromosomal regions susceptible to present breaks, discontinuities or constrictions in metaphase chromosomes from cells subjected to replication stress. They are considered as genomic regions intrinsically difficult to replicate and they are evolutionary conserved at least in mammals. However, the recent discovery that CFSs are cell-type specific indicates that DNA sequence by itself cannot account for CFS instability. Nevertheless, the large gene FHIT that includes FRA3B, the most highly expressed CFS in human lymphocytes, is commonly deleted in a variety of tumors suggesting a tumor suppressor role for its product. Here, we report that the epicenter of fragility of Fra14A2/Fhit, the mouse ortholog of human FRA3B/FHIT that like its human counterpart is the most highly expressed CFS in mouse lymphocytes, is largely attached to the nuclear matrix compartment in naive B lymphocytes but not in primary hepatocytes or cortical neurons that do not express such a CFS. Our results suggest a structural explanation for the difficult-to-replicate nature of such a region and so for its common fragility in lymphocytes, that is independent of the possible tumor suppressor role of the gene harboring such CFS. 相似文献