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排序方式: 共有4727条查询结果,搜索用时 125 毫秒
21.
Black willow (Salix nigra Marsh.) is the largest and only commercially important willow species in North America. It is a candidate for phytoremediation of polluted soils because it is fast-growing and thrives on floodplains throughout eastern USA. Our objective was to develop a protocol for the in vitro regeneration of black willow plants that could serve as target material for gene transformation. Unexpanded inflorescence explants were excised from dormant buds collected from three source trees and cultured on woody plant medium (WPM) supplemented with one of: (1) 0.1 mg l(-1) thidiazuron (TDZ); (2) 0.5 mg l(-1) 6-benzoaminopurine (BAP); or (3) 1 mg l(-1) BAP. All plant growth regulator (PGR) treatments induced direct adventitious bud formation from the genotypes. The percentage of explants producing buds ranged from 20 to 92%, depending on genotype and treatment. Although most of the TDZ-treated inflorescences produced buds, these buds failed to elongate into shoots. Buds on explants treated with BAP elongated into shoots that were easily rooted in vitro and further established in potting mix in high humidity. The PGR treatments significantly affected shoot regeneration frequency (P < 0.01). The highest shoot regeneration frequency (36%) was achieved with Genotype 3 cultured on 0.5 mg l(-1) BAP. Mean number of shoots per explant varied from one to five. The ability of black willow inflorescences to produce adventitious shoots makes them potential targets for Agrobacterium-mediated transformation with heavy-metal-resistant genes for phytoremediation. 相似文献
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Hossain Mohammad M. Scott Ian M. McGarvey Brian D. Conn Kenneth Ferrante Lorenzo Berruti Franco Briens Cedric 《Journal of pest science》2015,88(1):171-179
Journal of Pest Science - Conflicting views regarding synthetic pesticides include the successful use as pest management tools for agriculture and forestry on one hand and the threats to components... 相似文献
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Survival and behavioural responses of cool and warm water fish sedated with AQUI‐S®20E (10% eugenol) at high loading densities 下载免费PDF全文
Aaron R Cupp Kim T Fredricks Scott T Porcher Justin R Smerud Christopher F Hartleb Mark P Gaikowski 《Aquaculture Research》2017,48(4):1576-1589
This study evaluated the effects of AQUI‐S®20E (10% eugenol) sedation on the survival and behaviour of yellow perch Perca flavescens (Mitchill) and Nile tilapia Oreochromis niloticus L. held in high loading densities. Fish were held in 0–300 mg L?1 AQUI‐S®20E (0–30 mg L?1 eugenol) for up to 10 h in static tanks. At 17°C, yellow perch held in 200 and 300 mg L?1 AQUI‐S®20E were lightly sedated for up to 7 h. Yellow perch at 200 and 300 mg L?1 AQUI‐S®20E also had >95% mean survival 7‐days post exposure using loading densities up to 360 g L?1. Nile tilapia were only sedated for ≤3 h in concentrations up to 300 mg L?1 at 22°C and had >90% mean survival at loading densities ≤480 g L?1. Ammonia in tanks increased significantly as loading density increased, but treatment with AQUI–S®20E did not reduce ammonia accumulation. Results suggest that AQUI–S®20E was effective to sedate yellow perch and Nile tilapia at high loading densities, but sedation varied with loading density and species. 相似文献
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S J Monaghan S M Bergmann K D Thompson L Brown T Herath J del‐Pozo A Adams 《Journal of fish diseases》2017,40(8):1041-1054
Cyprinid herpesvirus 3 (CyHV‐3) is an alloherpesvirus, and it is the aetiological agent of koi herpesvirus disease. Although the complex morphogenic stages of the replication cycle of CyHV‐3 were shown to resemble that of other members of the Herpesvirales, detailed analysis of the sequence and timing of these events was not definitively determined. This study describes these features through a time course using cyprinid cell cultures (KF‐1 and CCB) infected with CyHV‐3 (KHV isolate, H361) and analysed by transmission electron microscopy. Rapid viral entry was noted, with high levels of intracellular virus within 1–4 h post‐infection (hpi). Intranuclear capsid assembly, paracrystalline array formation and primary envelopment of capsids occurred within 4 hpi. Between 1 and 3 days post‐infection (dpi), intracytoplasmic secondary envelopment occurred, as well as budding of infectious virions at the plasma membrane. At 5–7 dpi, the cytoplasm contained cytopathic vacuoles, enveloped virions within vesicles, and abundant non‐enveloped capsids; also there was frequent nuclear deformation. Several morphological features are suggestive of inefficient viral assembly, with production of non‐infectious particles, particularly in KF‐1 cells. The timing of this alloherpesvirus morphogenesis is similar to other members of the Herpesvirales, but there may be possible implications of using different cell lines for CyHV‐3 propagation. 相似文献
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Sui Chian Phang Michael Cooperman Abigail J. Lynch E. Ashley Steel Vittoria Elliott Karen J. Murchie Steven J. Cooke Scott Dowd Ian G. Cowx 《水产资源保护:海洋与淡水生态系统》2019,29(7):1039-1051
- The ecosystem services provided by freshwater biodiversity are threatened by development and environmental and climate change in the Anthropocene.
- Here, case studies are described to show that a focus on the shared dependence on freshwater ecosystem functioning can mutually benefit fisheries and conservation agendas in the Anthropocene.
- Meeting the threat to fish biodiversity and fisher livelihood is pertinent in developing regions where there is often a convergence between high biodiversity, high dependency on aquatic biota and rapid economic development (see Kafue River, Logone floodplain, Tonle Sap, and Rio Negro case studies).
- These case studies serve as evidence that biodiversity conservation goals can be achieved by emphasizing a sustainable fisheries agenda with partnerships, shared knowledge and innovation in fisheries management (see Kafue River and Kenai River case studies).
- In all case studies, aquatic biodiversity conservation and fisheries agendas are better served if efforts focused on creating synergies between fishing activities with ecosystem functioning yield long‐term livelihood and food security narratives.
- A unified voice from conservation and fisheries communities has more socio‐economic and political capital to advocate for biodiversity and social interests in freshwater governance decisions.
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Marjolaine Caillat Line Cordes Paul Thompson Jason Matthiopoulos Sophie Smout 《水产资源保护:海洋与淡水生态系统》2019,29(Z1):101-118
- Identifying and understanding ecological drivers that influence wildlife populations is challenging but critical for conservation. This typically requires integrating long‐term data on both the population and potential drivers within statistical models that are suitable for analysing these complex relationships. State‐space models offer one method for integrating such data. Once implemented within a Bayesian framework, these analyses can control for multifactorial influences on populations, allowing one to extract otherwise undetectable correlations between the environment and the underlying, inferred demography.
- In the Moray Firth, Scotland, harbour seals have been counted annually for 30 years (1988–2018). A Bayesian state‐space model was used to explore whether patterns in vital rates were correlated to changes in prey abundance, inter‐specific competition (grey seal abundance), environmental variables [the North Atlantic Oscillation (NAO) and sea‐surface temperature], or level of biotoxins (saxitoxin and domoic acid) in the Moray Firth waters.
- The credible interval of the posterior distributions of three of these covariate coefficients (sandeel proxy, NAO and grey seal abundance) suggested that there was a relationship between those covariates and vital rates. Both the sandeel proxy and NAO showed a positive correlation with fecundity, whereas grey seal abundance had a negative impact on pup survival.
- This work demonstrates how an integrated state‐space modelling approach can bring together diverse data sets and point to important interactions with prey, and with other predators in the system. This suggests that the wider‐scale management of UK harbour seal populations with their contrasting temporal trends needs to account for variation in the marine ecosystem at appropriate spatial scales, in line with current policy concerning spatial planning in the marine environment.
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