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351.
日本柑橘黄龙病病原体电镜观察及PCR检测   总被引:3,自引:3,他引:0  
对日本柑橘黄龙病病原体的形态结构进行了电镜观察,结果发现柑橘黄龙病病菌日本株系绝大多数是球形和短椭圆形,极少观察到棒状形态,直径为100~500nm,外被一层胶状物质包围,厚约10~50nm,这与其他地区发现的柑橘黄龙病病原体形态不同.PCR检测表明,以硅藻土法提取的DNA为模板,利用Ready-To-Go^TM PCR bead法可以得到理想结果。  相似文献   
352.
A critical component of many releasing projects is the identification and subsequent implementation of optimal release strategies that can decrease post-release predation mortalities. We performed laboratory experiments to investigate whether acclimation to shelters affects the post-release survival of hatchery-reared black-spot tuskfish Choerodon schoenleinii in the presence of a reef-resident predator, the white-streaked grouper Epinephelus ongus. Tuskfish were exposed to groupers under three different experimental conditions/treatments: (1) acclimation of fish to shelters prior to their exposure to groupers; (2) no acclimation of fish to shelters, but with shelters available during their exposure to groupers; (3) fish not acclimated to shelters and no shelters available during their exposure to groupers. Tuskfish that were acclimated to shelters utilized shelters more frequently than did non-acclimated fish, and the survival rate of acclimated fish was higher than those of fish in the other treatments. These results suggest that pre-release acclimation to shelters improves the post-release survival of hatchery-reared black-spot tuskfish.  相似文献   
353.
Fisheries Science - The marbled flounder Pseudopleuronectes yokohamae, a flatfish found in temperate coastal waters, is an important commercial species in the northwestern Pacific Ocean, but little...  相似文献   
354.
Amplification of eight microsatellite loci previously developed and characterized in brown sole Pleuronectes herzensteini was attempted in 11 other flatfish species. Two loci, Phz6 and Phz12, were amplified in all the species examined. Cross-species amplification was successful in eight loci of Kareius bicoloratus and Pleuronectes yokohamae, but in only seven loci of Microstomus achne, Pleuronectes punctatissimus, and Pleuronectes schrenki. Three to five loci could be amplified in six other species. In the three species selected, K. bicoloratus, P. punctatissimus, and P. yokohamae, seven to eight cross-amplified loci exhibited polymorphisms comprising 1–22 alleles. Expected heterozygosity (He) ranged from 0.66 to 0.96 in K. bicoloratus, from 0.62 to 0.96 in P. punctatissimus, and from 0.43 to 0.91 in P. yokohamae. Observed heterozygosity (Ho) ranged from 0.65 to 1.00 in K. bicoloratus, from 0.55 to 0.95 in P. punctatissimus, and from 0.40 to 0.95 in P. yokohamae. The Phz2, Phz3, and Phz12 loci significantly deviated in certain or all three species from Hardy–Weinberg equilibrium. The mean values of homology to the flanking-region sequences of brown sole were 93.7% in K. bicoloratus, 91.2% in P. punctatissimus, and 93.9% in P. yokohamae. These results suggest that microsatellite markers for brown sole are applicable for genetic studies in flatfish species including at least these three species.  相似文献   
355.
Otolith microchemical analyses of the strontium (Sr) and calcium (Ca) concentrations in the eels Anguilla japonica and A. anguilla caught in Tokyo Bay were undertaken to reconstruct the eels’ migratory histories. A. japonica in the yellow stage (immature stage) were caught in a bay without any adjacent rivers or streams. A. anguilla was in the silver stage (early maturing stage), and the eel was confirmed to have just begun spawning migration to the open ocean from Tokyo Bay based on the otolith Sr:Ca ratios, which showed a typical catadromous life history with low Sr:Ca ratio values throughout the eel’s life after recruitment. The mean Sr:Ca ratios in A. japonica from the elver mark to the otolith edge indicated the eels belonged to several general categories of migratory histories, including sea eels (average Sr:Ca ratio ≥6.0 × 10−3) and estuarine eels (average Sr:Ca ratio 2.5 to 6.0 × 10−3) based on the criteria reported previously in A. japonica. All eels had a certain freshwater life period, although the period was highly variable among fish. These results indicate that A. japonica has a flexible pattern of migration, with the ability to adapt to various habitats and salinities.  相似文献   
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