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1.
The establishment of large numbers of ramets from any individual coral genet can be used as a valuable source of material for the trade in ornamental marine organisms and in physiological and ecotoxicological studies. Here we discuss the rationale and the applicability of rearing ex situ large numbers of nubbins (minute fragments, down to the size of a single polyp). Nubbins taken from colonies of the branching Red Sea coral Stylophora pistillata show high survivorship under ex situ conditions and fast growth rates (5- to 6-fold increase in polyp numbers within 3 months) of the basal plates which revealed a significant correlation between tissue surface area and polyp numbers. Nubbins from branch tips and mid branches grew at a similar rate, but growth was affected by different light regimens. This approach requires further experimentation to elucidate optimal conditions. 相似文献
2.
The worldwide market for ornamental saltwater invertebrates supplies the needs of millions of aquarium hobbyists, as well as for public exhibition (zoos, aquaria), universities, and research institutions. The large-scale continuous collection of marine organisms is responsible, in many places, for the destruction of habitats, including coral reefs. The perceived expansion of the animal trade further threatens these fragile habitats. In the present paper, several concepts for the domestication of marine ornamental invertebrates (mainly colonial species) are discussed, offering an alternative commercial approach. The major rationale is based on future ex situ propagation, not field collections; a strategy aimed to circumvent the need for wild-harvested animals. This strategy is based on: (1) collection, settlement and metamorphosis of large numbers of larvae from marine organisms or of naturally shed germ cells under aquarium conditions, where survivorship exceeds several orders of magnitude than that in nature; (2) fragmentation of very small pieces (such as the size of a single polyp in colonial corals or blood vessel ampullae in tunicates) for the production of new colonies; (3) the development of replicates and inbred-lines from chosen ornamental species; (4) the use of cryopreservation of larvae and germ cells which will support the supply of material year-round; (5) several concepts for husbandry methods. Some benefits and deficiencies associated with the strategy for ex situ cultures are discussed, revealing its importance to the future of the trade. 相似文献
3.
Midatharahally Narasegowda Maruthi Henryk Czosnek Favi Vidavski Shlomo-Yedidia Tarba Judith Milo Shai Leviatov Hagalawadi Mallithimmaiah Venkatesh Attiganal Seetharam Padmaja Rudrappa Subbappa Kulkarni Venkataramappa Muniyappa 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(1):1-11
The objective of this study was to screen wild and domesticated tomatoes for resistance to Tomato yellow leaf curl virus, Israel (TYLCV-Is) and Tomato leaf curl virus from Bangalore isolate 4, India (ToLCV-[Ban4]) to find sources of resistance to both viruses. A total of 34 tomato genotypes resistant/tolerant to TYLCV-Is were screened for resistance to ToLCV-[Ban4] under glasshouse and field conditions at the University of Agricultural Sciences, Bangalore, India. Resistance was assessed by criteria like disease incidence, symptom severity and squash-blot hybridization. All the tomato genotypes inoculated with ToLCV-[Ban4] by the whitefly vector Bemisia tabaci (Gennadius) produced disease symptoms. In some plants of the lines 902 and 910, however, the virus was not detected by hybridization. The tomato genotypes susceptible to ToLCV-[Ban4] by whitefly-mediated inoculation were also found susceptible to the virus under field conditions. However, there were substantial differences between genotypes in disease incidence, spread, symptom severity and crop yield. Despite early disease incidence, many genotypes produced substantially higher yields than the local hybrid, Avinash-2. Sixteen tomato genotypes from India resistant/tolerant to ToLCV-[Ban4] were also tested for TYLCV-Is resistance at the Hebrew University of Jerusalem, Rehovot, Israel. Accessions of wild species, Lycopersicon hirsutum LA 1777 and PI 390659 were the best sources of resistance to both viruses. Lines 902 and 910, which were, resistant to TYLCV-Is were only tolerant to ToLCV-[Ban4] and accession Lycopersicon peruvianum CMV Sel. INRA, resistant to ToLCV-[Ban4], was only tolerant to TYLCV-Is. Implications of using the resistant lines in breeding programme is discussed. 相似文献
4.
G. Darrel Jenerette Sharon L. Harlan Alexander Buyantuev William L. Stefanov Juan Declet-Barreto Benjamin L. Ruddell Soe Win Myint Shai Kaplan Xiaoxiao Li 《Landscape Ecology》2016,31(4):745-760
Context
With rapidly expanding urban regions, the effects of land cover changes on urban surface temperatures and the consequences of these changes for human health are becoming progressively larger problems.Objectives
We investigated residential parcel and neighborhood scale variations in urban land surface temperature, land cover, and residents’ perceptions of landscapes and heat illnesses in the subtropical desert city of Phoenix, AZ USA.Methods
We conducted an airborne imaging campaign that acquired high resolution urban land surface temperature data (7 m/pixel) during the day and night. We performed a geographic overlay of these data with high resolution land cover maps, parcel boundaries, neighborhood boundaries, and a household survey.Results
Land cover composition, including percentages of vegetated, building, and road areas, and values for NDVI, and albedo, was correlated with residential parcel surface temperatures and the effects differed between day and night. Vegetation was more effective at cooling hotter neighborhoods. We found consistencies between heat risk factors in neighborhood environments and residents’ perceptions of these factors. Symptoms of heat-related illness were correlated with parcel scale surface temperature patterns during the daytime but no corresponding relationship was observed with nighttime surface temperatures.Conclusions
Residents’ experiences of heat vulnerability were related to the daytime land surface thermal environment, which is influenced by micro-scale variation in land cover composition. These results provide a first look at parcel-scale causes and consequences of urban surface temperature variation and provide a critically needed perspective on heat vulnerability assessment studies conducted at much coarser scales.5.
6.
Abstract – The aquatic environment is being perturbed globally through increases in turbidity, which can have detrimental effects for the maintenance of fish diversity, especially in species dependent on visual cues for reproduction and species recognition. We performed a short‐term manipulation of the visual environment in Lake Malawi to test for an immediate behavioural response to increased turbidity in territorial rock‐dwelling cichlid fishes that use colourful visual cues to maintain territories near the substrate and attract mates. We found a significant movement of fish away from the substrate, with a concomitant shift from displaying territorial and courting behaviours to foraging behaviours, during the five minutes following the release of a turbidity plume over the area. This study is the first to test for and demonstrate an immediate behavioural response of a natural fish population to a short‐term increase in turbidity that might mimic the initial (i.e., immediate) stage of a run‐off event after rainfall in a deforested area. 相似文献
7.
Sensory organs are composed of neurons, which convert environmental stimuli to electrical signals, and glia-like cells, whose functions are not well understood. To decipher glial roles in sensory organs, we ablated the sheath glial cell of the major sensory organ of Caenorhabditis elegans. We found that glia-ablated animals exhibit profound sensory deficits and that glia provide activities that affect neuronal morphology, behavior generation, and neuronal uptake of lipophilic dyes. To understand the molecular bases of these activities, we identified 298 genes whose messenger RNAs are glia-enriched. One gene, fig-1, encodes a labile protein with conserved thrombospondin TSP1 domains. FIG-1 protein functions extracellularly, is essential for neuronal dye uptake, and also affects behavior. Our results suggest that glia are required for multiple aspects of sensory organ function. 相似文献
8.
Aharoni Ran Klymiuk Valentyna Sarusi Benny Young Sierra Fahima Tzion Fishbain Barak Kendler Shai 《Precision Agriculture》2021,22(1):267-286
Precision Agriculture - Yellow rust (YR) wheat disease is one of the major threats to worldwide wheat production, and it often spreads rapidly to new and unexpected geographic locations. To cope... 相似文献
9.
Wilson M Moshitzky P Laor E Ghanim M Horowitz AR Morin S 《Pest management science》2007,63(8):761-768
Pyriproxyfen, a juvenile hormone (JH) mimic, is a biorational insecticide that disrupts insect development. It is one of the principal insecticides being used to control Bemisia tabaci (Gennadius) on cotton, and has many environmentally positive attributes that make it compatible with integrated pest management (IPM) programs. In Israel, a high level of resistance to pyriproxyfen has been observed in several isolated regions. Here, tests were conducted to establish whether temporal refuges from exposure to pyriproxyfen could be useful for restoring the effectiveness of the compound. Resistance was found to decrease by a factor of 8 when exposure to pyriproxyfen was ceased for 13 generations. Reversal of resistance was accompanied with increased biotic fitness of the revertant colony. By incorporating experimental estimates of nymph survival, sex ratio, fecundity, egg hatching rate and developmental time, the seasonal cost per generation for resistant insects was estimated to be 25%. A genetic simulation model, optimized by empirical data from bioassays, predicted fitness cost per generation of 19% for resistant homozygous (RR) females and hemizygous (R) males, and produced rates of reversal similar to the experimental results. The model also predicted that, even after 5 years ( approximately 55 generations) without pyriproxyfen treatments, the frequency of the resistance allele (R) will still remain high (0.02). It is therefore concluded, on the basis of experimental and modeling results, that the effectiveness of temporal refuges for reversing development of resistance to pyriproxyfen in B. tabaci may be limited. 相似文献
10.
Koussevitzky S Nott A Mockler TC Hong F Sachetto-Martins G Surpin M Lim J Mittler R Chory J 《Science (New York, N.Y.)》2007,316(5825):715-719