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51.
皱纹盘鲍(Haliotis discus hannai Ino)是我国重要的经济海洋生物资源,以其营养价值高、味道鲜美而居海产八珍之首。由于资源的过度采捕、日益增加的养殖活动及海区环境污染等,可能会使皱纹盘鲍的遗传结构发生改变,继而影响到其适合度。为了种质资源的保护和可持续利用,同时也为了进一步完善皱纹盘鲍苗种繁育技术工艺,对我国近海皱纹盘鲍野生群体的遗传结构和变异研究是很有必要的。 等位基因酶电泳技术是研究海洋贝类遗传结构与变异的重要手段之一。目前世界上已有近百种海洋贝类的遗传结构和变异得到研究(张国范,1992;张国范等, 1993),皱纹盘鲍日本分布区不同群体遗传结构和变异研究也有相关报道(Fu jino et al., 1978)。本文作者采用等位基因酶电泳技术,随机选取了24个等位基因位点,对皱纹盘鲍我国分布区内四个野生群体的遗传结构和变异进行研究,为我国皱纹盘鲍种质资源研究和可持续利用提供基础数据。  相似文献   
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新疆且末县黄羊沟地区蛇绿混杂岩带的发现及其意义   总被引:3,自引:0,他引:3  
在新疆且末县黄羊沟地区首次发现蛇绿混杂岩带。该岩带由超基性岩、基性岩及石炭系、二叠系变质岩混杂堆积而成,从北向南可进一步划分为3个亚带。  相似文献   
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Extraction of molybdenum and vanadium from ammonia leaching residue (main chemical composition: 2.05% Mo, 0.42% V, 65.6% Al2O3 and 10.7% SiO2) of spent catalyst was investigated by roasting the residue with soda carbonate, followed by hydrometallurgical treatment of the roasted products. In the roasting process, over 91.3% of molybdenum and 90.1% of vanadium could be extracted when a charge containing a sodium carbonate to spent catalyst ratio of 0.15 was roasted at 750 °C for 45 min and the roasted mass was leached with water (liquid to solid ratio of 2) at 80–90 °C for 15 min. After the purification of leach liquor, an extraction solvent consisting of 20 vol.% trialkylamine (N235, commercialized in China) and 10 vol.% secondary octyl alcohol (phase modifier) dissolved in sulfonated kerosene was used to extract molybdenum and vanadium in leach liquor. 10 wt.% ammonia water was used as stripping agent. Adding 30 g/l NH4NO3 to the stripping solution and adjusting the pH to 7–8.5, over 99% of vanadium can be crystallized as ammonium metavanadate. Over 98% of molybdenum can be crystallized as ammonium polymolybdate when pH is between 1.5 and 2.5 (pH is adjusted by HNO3). Ammonium metavanadate and ammonium polymolybdate were calcinated at 500–550 °C, the purity of MoO3 and V2O5 was 99.08% and 98.06% respectively. In the whole process, 88.2% of molybdenum and 87.1% of vanadium could be achieved. The proposed roasting, leaching and separation steps give a feasible alternative for the processing of ammonia leaching residue of spent catalyst and can be applied in the comprehensive utilization of low grade molybdenum ores.  相似文献   
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The high phenotypic plasticity in the shell of oysters presents a challenge during taxonomic and phylogenetie studies of these economically important bivalves. However, because DNA can exhibit marked differences among morphologically similar species, DNA barcoding offers a potential means for oyster identification. We analyzed the complete sequences of the cytochrome oxidase subunit I (COI) of five common Crassostrea species in China (including Hong Kong oyster C. hongkongensis, Jinjiang oyster C. ariakensis, Portuguese oyster C. angulata, Kumamoto oyster C. sikamea, and Pacific oyster C. gigas) and screened for distinct fragments. Using these distinct fragments on a high-resolution melting analysis platform, we developed an identification method that does not rely on species-specific PCR or fragment length polymorphism and is efficient, reliable, and easy to visualize. Using a single pair of primers (Oyster- COI-1), we were able to successfully distinguish among the five oyster species. This new method provides a simple and powerful tool for the identification of oyster species.  相似文献   
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了解近交效应对评估贝类长期育种的可行性及分析自交和全同胞交配子代的近交衰退有重要意义。海湾扇贝是典型的性腺雌区与雄区严格分开的雌雄同体型海洋贝类,行体外受精。它是研究贝类遗传近交衰退和交配系统进化的一个模式物种。目前双壳贝类的近交衰退研究多集中在表型和分子标记等方面,但基因组表达层面的研究较少。本研究比较了亲本遗传背景相同的海湾扇贝近交系F=0.5和杂交系闭壳肌组织的基因表达。表型方面:近交系和杂交系在某些生长性状有差异,其中近交系的壳长和总重低于杂交系。基因表达方面:自交系有1175个基因表达量上调,1390个基因表达量下调。差异表达基因主要集中在肌原纤维、收缩纤维和细胞质膜等。GO功能富集主要集中在转移酶、磷酸酶、蛋白激酶和活性肽等方面。差异明显的通路主要集中在氧化磷酸化通路和细胞凋亡通路。利用独立亲本的近交系和杂交系采用qRT-PCR技术,验证了近交系的差异表达基因主要参与氧化磷酸化通路和细胞凋亡通路, 说明自交能影响能量代谢和自稳态。  相似文献   
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The bottom aquaculture of yesso scallop(Pa tinopecten yessoensis)has developed rapidly in the north of Yellow Sea,China,but not without accompanying productivity problems.We,therefore,conducted field surveys to investigate factors related to growth and mortality rates of bottom-cultured scallops after release.Specifically,we focused on the effects of total antioxidant capacity(TAOC)and three key enzymes involved in antioxidant and metabolic function:glutamic pyruvic transaminase(GPT),lactic dehydrogenase(LDH),and superoxide dismutase(SOD).Across summer and winter,we also measured the relative mRNA expression of GPT and SOD to understand their seasonal variation in the scallops,along with how such variation correlated to growth and mortality.Results show that bottom cultured scallops experienced mass mortality during the first six months post-release.During winter(December),scallops grew more rapidly and suffered less mortality than in summer(August).The observed lower performance probably resulted from less advantageous environmental factors during the summer seasons,such as high temperature and low dissolved oxygen.These environmental stressors enhance protein consumption while decreasing energetic resources in scallops.Furthermore,scallops in summer exhibited high antioxidant levels that probably competed for energy with process integral to growth and survival.These negative factors combined to elevate mortality rates.In conclusion,we provided evidence suggesting correlations between metabolic/antioxidant activity and growth and mortality of bottom-cultured yesso scallops.These correlations implied us an accurate method to estimate the performance of bottom culture system.Suggestions about innovative aquaculture techniques were also discussed in the study.Our results might provide a possible guideline to the improvement of bottom culture techniques for this commercially valuable seafood species.  相似文献   
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