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924.
Microsatellite DNA variation was used to assess the outcome of stocking Atlantic salmon Salmo salar and migratory trout Salmo trutta in River Sävarå, N Sweden. No information on pre‐stocking genetic composition of S. salar and S. trutta in River Sävarå was available. In 2 year‐classes of S. salar smolt, microsatellite data indicated that post‐stocking genetic composition differed markedly (FST= 0·048) from the main donor strain, Byskeälven S. salar, and from other Gulf of Bothnia S. salar stocks (FST 0·047 and 0·132). The STRUCTURE programme failed to detect any substructuring within Sävarå salmon. It was concluded that only minor introgression estimated to a proportion of 0·11 (95% CI 0·07–0·16) has occurred in S. salar. Salmo trutta showed overall low differentiation among populations with maximum FST of 0·03 making analysis more cumbersome than in S. salar. Still, the SävaråS. trutta deviated significantly from potential donor populations, and STRUCTURE software supported that majority of trout in Sävarå formed a distinct genetic population. Admixture was more extensive in S. trutta and estimated to 0·17 (95% CI 0·10–0·25).  相似文献   
925.
Effects of Paclobutrazol on Response of Two Barley Cultivars to Salt Stress   总被引:1,自引:0,他引:1  
The seeds of two barley (Hordeum vulgare L.) cultivars (a drought resistant cv. Tokak-137/57 and a drought sensitive cv. Erginel-90) were imbibed either in distilled water (control) or in a solution containing 40 mg dm−3 paclobutrazol (PBZ) and air dried. Seeds were germinated and grown in a glasshouse for 21 d and seedlings were subjected to salt stress by treating them with 100 and 200 mM NaCl for 12 d. The height of shoots was significantly decreased and root length was increased in PBZ-treated plants prior and after NaCl stress for 12 d leading to an increase in root to shoot ratio. Leaf chlorophyll and carotenoid contents in PBZ treated plants were increased in controls and especially in plants subjected to salt stress. PBZ induced increase in superoxide dismutase (SOD) activities was higher in cv. Tokak-157/37, than in cv. Erginel-90. However, an increase in SOD activity was not accompanied by an increase in peroxidase activity. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
926.
Dye plants that are commonly used by the regional people of East Anatolia were studied. The following information was collected: local name of plants, the part of plants containing dye, obtained color, dying substances, and extraction of colors. As a result of area investigations carried out between 1994 and 2000, 50 taxa (used for dying wool yarns in the region) belonging to 38 genera and 26 families were determined from collected specimens By using the dying plants and mediator substances, 15 different colors and tones can be obtained. The main colors are yellow, green, olive green, black, red, blue, dark blue, brown, gray, beige, orange, khaki, mustard, purple, and smoke. The colors and their many different tones were observed on kilims and carpets that are woven in the East Anatolia region of Turkey  相似文献   
927.
We examined coral reef communities at 11 sites within Mafia Island Marine Park using a point count method for substrate and visually censused belt transects for fish populations. Multivariate ordinations showed that the benthic habitat differed among reefs. The patterns were mainly attributed to variations in depth, hydrodynamics and benthic composition. In total, the substratum was dominated by dead coral (49%) and algae (25%), with a live coral cover of only 14%. Three hundred and ninety-four fish species belonging to 56 families were recorded. According to MDS-ordinations and RELATE procedures, fish assemblage composition varied among sites in concordance with the habitats provided. Sites with highest proportion of dead coral exhibited highest degree of dispersion in the multivariate ordinations of fish assemblages. Stepwise multiple regression was used to determine the proportion of variance among sites which could be explained by depth, exposure, rugosity, substrate diversity, branching substrate, live coral cover, dead coral cover and different types of algae. The results showed that habitat variables explained up to 92% of the variation in species numbers and in total, and taxon-specific, abundance. Live coral cover was the foremost predictor of both numerical and species abundance, as well as of corallivores, invertivores, planktivores and of the families Pomacentridae, Chaetodontidae and Pomacanthidae. Our results suggest that habitat characteristics play a dominant role in determining fish assemblage composition on coral reefs.  相似文献   
928.
The reservoirs studied are located on a very important migratory flyway in the Mexican Central Plateau. The survey included the waterfowl, macrophytes and physico-chemical parameters of three localities visited on ten occasions during a 1-year period. A total of 23 waterfowl species were observed: 6 transients, 10 winter visitants, and 7 residents. A period of increased richness was detected in winter, when migratory species arrive at the reservoirs. A canonical correspondence analysis showed segregation patterns of the species for the use of the space. Migratory ducks occurred in Umécuaro, where there is a larger variety of macrophytes and eutrophication occurs. Loma Caliente was the area with less eutrophication and was not preferred by ducks. Gallinago gallinago and Ardea herodias were the species with the highest frequency of occurrence, while the Effluent was the preferred site of resident species. Although the reservoirs studied are small, they are suitable for a significative number of species to be considered as a waterfowl protection and conservation zone.  相似文献   
929.
The cultivated sunflower (Helianthus annuus L.) is one of the most important oil crops in the world. The importance of sunflower oil in human nutrition and in the chemical industry makes the sunflower a major research interest. An essential element for genomic libraries is the preparation of high molecular weight (HMW) DNA. We developed 2 methods for isolating HMW sunflower DNA. We prepared the DNA from nuclei and from protoplasts isolated from mesophyll tissue with the enzymes cellulase RS and pectolyase Y23. The HMW DNA was digested with restriction endonucleases. The ethidium bromide-stained gel suggested the DNA to be completely digested. These results were confirmed by Southern analysis using a radiolabeled RFLP marker. Both methods made it possible to generate sufficient quantities of megabase-size sunflower DNA suitable for bacterial artificial chromosome (BAC) cloning.  相似文献   
930.
Seven strains of axenic unicellular Chlorophyta and three strains ofaxenic Cyanophyta were selected for their high growth rate and positivecytokinin-like activity in the Cucumber Cotyledon Expansion Bioassay. Ethanolicextracts of these ten strains were purified using cation exchange resin andpaper chromatography and then screened for cytokinin-like activity using theSoybean Callus Bioassay. No trend was detected in the Cyanophyta with onespecies having two peaks of cytokinin-like activity co-eluting with zeatinderivatives and iso-pentenyladenine derivatives and theother two species having only one peak of activity co-eluting with zeatinderivatives. Four Chlorophyta only had one peak of cytokinin-like activity,co-eluting with zeatin derivatives, while two species had two peaks of activityco-eluting with zeatin and iso-pentenyladeninederivatives.One Chlorophyta species had no detectable cytokinin-like activity. The same tenstrains were also tested for auxin-like activity. The water extract of sevenstrains demonstrated auxin-like activity in the Cucumber Cotyledon RootFormation Bioassay. No auxin-like activity was detected in any of the strainsusing the Mung Bean Bioassay after being extracted in methanol and purified byphase partitioning with phosphate buffer and ethyl acetate.  相似文献   
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