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许氏平鲉(Sebastes schlegeli)微卫星标记开发及野生、养殖群体遗传多样性分析 总被引：1，自引：1，他引：0
对许氏平鲉进行简化基因组测序,设计微卫星引物200对,可稳定扩增的引物190对,占95%。利用一个荣成野生群体对24个多态性较高的微卫星标记进行了评价,每个位点的等位基因数(Na)为2—21个,观测杂合度(Ho)为0.0417—0.9167,期望杂合度(He)为0.0278—0.9722,多态信息含量(PIC)为0.1948—0.9496,结果显示有20个微卫星位点为中高度多态。利用这些引物对荣成野生群体和烟台养殖群体的遗传多样性进行了比较分析,野生和养殖群体的平均等位基因数(Na)分别为8.5000、6.9583,有效等位基因数(Ne)的均值分别为4.5484、3.6365,期望杂合度(He)均值分别为0.6421、0.5840,多态信息含量均值(PIC)分别为0.6088、0.5490,平均香农-威纳指数均值为1.4605、1.2834,但F检验发现无显著差异,发现两个群体的遗传多样性都处于高度多态水平,但养殖群体遗传多样性水平低于野生群体。本研究结果说明许氏平鲉的人工繁育中,通过使用较大数量的亲本进行繁育可有效防止选育群体的遗传多样性降低,但人工定向选育对选育群体的遗传多样性也产生了一定的影响。Bonferroni校正后在两个群体中各有4个位点偏离Hardy-Weinberg平衡。本研究开发的微卫星标记为许氏平鲉遗传图谱构建、分子标记辅助育种等提供了更多标记选择,对野生和养殖群体遗传多样性分析为下一步的遗传育种提供参考。 相似文献
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采用线粒体(mtDNA)控制区序列分析方法,进行了条石鲷养殖群体(F1代和F2代)与野生群体的遗传变异比较研究.结果表明:在长度为484bp的mtDNA控制区片段中,条石鲷养殖群体F1代单倍型多样度水平(h=0.955±0.047)略低于野生群体(h=1.000±0.034),却显著高于养殖F2代群体(h=0.797±0.070);条石鲷野生群体(π=0.021±0.012)、养殖群体F1代(π=0.018士0.010)和养殖群体F2代(π=0.014±0.008)的核苷酸多样度水平呈现明显的递减趋势;核苷酸不配对分布和两两序列相比较碱基差异结果显示条石鲷野生群体、养殖群体F1代和养殖群体F2代也呈现明显的递减趋势.分子方差分析(AMOVA)、两两群体相比较的ΦsT和确切P检验结果皆显示条石鲷养殖群体F1代和F2代与野生群体存在显著的遗传分化.单倍型最小跨度分析和NJ系统分析结果均未检测到显著的谱系结构. 相似文献
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Daniele Brigolin Gabriele Dal Maschio Federico Rampazzo Michele Giani Roberto Pastres 《Estuarine, Coastal and Shelf Science》2009
The fluxes of carbon, nitrogen and phosphorus through an off-shore long-line Mytilus galloprovincialis farm during a typical rearing cycle were estimated by combining a simple population dynamic model, based on a new individual model, and a set of field data, concerning the composition of the seston, as well as that of mussel meat and faeces. The individual model, based on an energy budget, was validated against a set of original field data, which were purposely collected from July 2006 to May 2007 in the North-Western Adriatic Sea (Italy) and was further tested using historical data. The model was upscaled to the population level by means of a set of Monte Carlo simulations, which were used for estimating the size structure of the population. The daily fluxes of C, N and P associated with mussel filtration, excretion and faeces and pseudo-faeces production were integrated over the 10-month-long rearing cycle and compared with the total amount of C, N and P removed by harvesting. The results indicate that the individual model compares well with an existing literature model and provides reliable estimations of the growth of mussel specimen over a range of trophic conditions which are typical of the Northern Adriatic Sea coastal area. The results of the budget calculation indicate that, even though the harvest represents a net removal of phosphorus and nitrogen from the ecosystem, the mussel farm increases the retention time of both nutrients in the coastal area, via the deposition of faeces and pseudo-faeces on the sea-bed. In fact, the amount of nitrogen associated with deposition is approximately twice the harvested one and the amount of phosphorus is approximately five times higher. These findings are in qualitative agreement with the results of literature budget and model calculations carried out in a temperate coastal embayment. This agreement suggests that the proper assessment of the overall effect of long-line mussel farming on both the benthic and pelagic ecosystem asks for an integrated modelling approach, which should include the dynamic of early diagenesis processes, as well as of that of nutrients released from the surface sediment. 相似文献
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A2 × 2 factorial cross between two populations of Pacific abalone Haliotis discus hannai Ino, collected separately from Dalian （D） in China and Miyagi （M） in Japan, was conducted to compare performances in fertilization rate, hatching rate, metamorphosis rate and growth at days 20, 43, 160 and 330 between purebreds （DD and MM） and crossbreds （DM and MD） and investigate the magnitude of heterobeltiosis （better parent） and heterosis （mid-parent）. Heterobeltiosis and heterosis for all the traits analyzed were evidently different between crossbreds DM and MD. Heterobeltiosis in the crossbred DM varied among traits, with values of 2.5% for the fertilization rate, 2.2% for the hatching rate, - 1.9% for the metamorphosis rate and 7.4% for the growth at the day 330. The crossbred DM displayed positive heterotic values for fertilization rate （5.4%）, hatching rate （7.4%）, metamorphosis rate （7.6%） and growth （ 12.0% ） at the day 330. However, both heterobeltiosis and heterosis for all the traits in the crossbred MD were negative except those for the growth at days 20 and 43. The results indicate the importance of selecting superior hybrid varieties if the exploitation of hybrid vigor is considered in the Pacific abalone breeding program. 相似文献
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菲律宾蛤仔(Ruditapes philippinarum)大连群体家系建立及生长比较 总被引：2，自引：0，他引：2
于2008年6月,以大连野生型蛤仔为材料,采用巢式设计即1个雄性亲本与3个雌性亲本交配的方式建立了菲律宾蛤仔15个半同胞家系(A,B,…,O)和45个全同胞家系(A1,A2,A3,…,O1,O2,O3)。对各家系的壳长、壳宽、壳高、鲜重等各项指标进行了方差分析和多重比较。结果表明,3、4、5月龄,菲律宾蛤仔45个全同胞家系的表型性状具有显著差异,且各月龄的差异趋势基本一致。5月龄时,从其生长性状上看,家系F2、G2、G3表现出明显的生长优势,壳长分别提高28.43%、24.72%、30.53%,壳宽分别提高21.14%、22.3%、25.58%,壳高分别提高30.88%、26.96%、25.25%,鲜重分别提高50.00%、68.42%、44.12%。从其存活上看,家系E3的四个表型性状在全同胞家系中最小,但存活数量最多为2269粒,表现出很强的抗逆性;具有生长优势的家系F2存活个数最少仅为43粒,抗逆性相对最差。从其产量上看,家系N3、I1、E3、C1、N1、G2产量较高,分别比平均产量提高了77.8%、75.61%、75%、69.45%、53.96%、50.19%。综合以上各项指标家系G2、G3、N3、E3、I1、C1、N1可作为优良的家系育种材料,在下一步育种工作中可以利用家系选择及家系杂交的方法对7个家系进行遗传改良。 相似文献
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Stochastic virtual population analysis 总被引：2，自引：1，他引：1
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Myers R. A.; Barrowman N. J.; Hoenig J. M.; Qu Z. 《ICES Journal of Marine Science》1996,53(3):629-640
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小黄鱼是我国近海四种最重要的经济鱼类之一,在过去的几十年中小黄鱼种群及其两个地理亚种群经历了巨大的变化。小黄鱼的种群动力学研究,对于维持这一重要渔业的可持续管理是至关重要的。目前仅有的两个小黄鱼种群动力学模型只涵盖了较短的时间,且没有关注其空间差异。本文研究了1968年至2015年间黄渤海和东海小黄鱼的种群动力学模型,包含和不包含空间分层结构的两种贝叶斯模型被用于分析其种群动力学的大尺度空间异质性。本文分析了不同的假设,来研究小黄鱼种群动力学潜在的变化趋势。研究结果表明小黄鱼种群动力学特征具有明显的时间和空间变化。种群的增长速度从20世纪八十年代开始增加,而可捕系数从1981年到2015年增加了两倍多。与黄渤海亚种群相比,东海的小黄鱼亚种群生长速度更快,遭受的捕捞压力也更大。基于最大可持续产量MSY的参考点表明,无论是整个小黄鱼种群还是两个亚种群,近年来都有非常高的过度捕捞风险。因此我国小黄鱼的渔业管理急需更加保守的管理策略,同时考虑其地域差异。本文所用的方法可以应用于其他种类的资源评估和渔业管理,尤其是具有空间异质性和数据有限的种类。 相似文献
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采用放射性免疫(RIA)和组织学切片技术,系统地研究了虹鳟(Oncorhynchus mykiss)选育群体的血清性类固醇激素周年变化与性腺发育特点的关系,以及血清中性类固醇激素雌二醇(E2)和睾酮(T)在雌雄亲本中的周年变化规律和生理作用。结果表明,虹鳟性腺发育可划分为6期。雌鱼血清中E2在10月(V期性腺)达到峰值,T浓度在11月达到峰值,而进入繁殖期后(11—12月)E2开始下降。雄鱼血清T浓度在11月达到最大值,E2在6月份达到峰值,在11月之后T开始下降。在各月份,雌鱼E2浓度水平远高于雄鱼,而雄鱼T浓度个别月份低于雌鱼。这些研究揭示出,测定血清性类固醇激素浓度水平可用于准确判断鱼类的生殖状态,且可为虹鳟家系选育出早熟亲本群体提供重要技术依据。 相似文献
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Abstract. Population dynamics and secondary somatic production data of a population of the polychaete Hediste diversicolor (O. F. Müller) are reported. Monthly samples were taken in a small muddy-sand flat in the Gernika estuary (Basque Country, North Iberian Peninsula) from May 1991 to May 1992. In addition to H. diversicolor abundance, temporal variation of the infauna and sediment conditions were analysed. Size measurements were employed to estimate H. diversicolor biomass and several cohorts were differentiated based on the size distribution. Secondary production was estimated based on cohort summation of growth increments following individual cohorts through time. Results are compared with those of other H. diversicolor populations located along the whole latitudinal gradient of distribution of the species. 相似文献
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The coastal population of common bottlenose dolphins Tursiops truncatus found in Namibia is regionally isolated and unique. This population faces several potential anthropogenic threats, especially in Walvis Bay, including boat-based tourism, a commercial harbour undergoing expansion, and aquaculture for oysters and mussels. Between 2008 and 2012, 238 boat-based surveys were conducted, resulting in 170 encounters with bottlenose dolphins. Overall, group sizes varied from 1 to 45 individuals (mean 10.7). Encounter rates, group sizes and total numbers of animals identified were higher in winter than in summer field seasons. The number, and survival and immigration parameters, of bottlenose dolphins using Walvis Bay was investigated using robust design and Huggins closed-population mark-recapture models. The highest numbers estimated were in the first and last years of the study, with estimates of 74–82 in 2008 and 76–77 in 2012 (numbers identified and upper 95% confidence limits). The only previously available data, from an incomplete study in the early 1990s, suggested that the population was between 100 and 150 individuals at the time. Although no linear trend in population size was obvious during the current study, the clear evidence of isolation, small population size, low annual birth rate, and potential long-term decrease in numbers since the early 1990s is concerning. Further work to collect data on demographic parameters is urgently recommended with a view to obtaining increased protection for this species. 相似文献