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131.
132.
Simple sequence repeat (SSR) markers were obtained for the large yellow croaker Pseudosciaena crocea using 1 205 expressed sequences tags (ESTs) from the NCBI database. Primers for 48 ESTSSR loci were designed and screened with 30 P.crocea specimens captured from Guanjingyang sea area in Fujian Province of China. Sixteen of the loci were polymorphic, which were amplified with 3 to 11 alleles per locus and the mean of 6.13. The observed and expected heterozygosity per locus ranged from 0.091 to 0.844 (mean 0.544) and from 0.118 to 0.892 (mean 0.644), respectively. Polymorphic information content (PIC) ranged from 0.115 to 0.866 (mean 0.593). The results for cross-species amplification of the 16 large yellow croaker EST-SSRs on P. polyactis, C. niveatus, C. lucidus, A. argentatus and J. belengeri revealed that 14, 12, 11, 7 and 6 loci were successfully amplified with 1 to 10 alleles with an average of 4.5 per locus, respectively, which are suitable for population genetics studies of these species and useful for phylogenetic relationship analysis among these species. Overall, this study provides a set of type I markers for population genetics studies and genome mapping for large yellow croaker and its closely related species. 相似文献
133.
S7核糖体蛋白基因片段序列变异与花鲈属鱼类系统发育研究 总被引:1,自引:0,他引:1
对中国和日本海域花鲈属的3个种:花鲈(Lateolabrax maculatus)、鲈鱼(L. japoni-cus)和高体鲈(L. latus)的S7核糖体蛋白基因片段序列进行了扩增和序列测定,分析比较了3个种23个个体间的序列差异。在456bp的S7核糖体蛋白基因片段中,3个高体鲈个体中出现了3种单倍型,种内个体间有2个碱基差异;7个花鲈个体中出现了7种单倍型,种内个体间有21个碱基差异;13个鲈鱼个体中出现了12种单倍型,种内个体间有22个碱基差异。结果表明,花鲈属S7核糖体蛋白基因片段序列具有丰富的遗传信息,在亲缘关系较近的物种间也存在显著的序列差异,基于S7核糖体蛋白基因片段序列的NJ和ME系统树经1000次重复抽样检验后得到相似结果,表明S7基因内含子2是适合于研究分子系统发育的分子标记。利用Modeltest选取最佳核苷酸替代模型构建的NJ树表明:花鲈属鱼类由高体鲈分化,花鲈与鲈鱼的亲缘关系很近,而与高体鲈的亲缘关系较远。 相似文献
134.
Effects of temperature, pH and NaCl on protease activity in digestive tract of young turbot, Scophthalmus maximus 总被引:3,自引:0,他引:3
1 INTRODUCTION Digestive enzyme activity is one of important issues for learning digestive physiology of fish, and widely applied in commercial fish culture. So far, the data obtained in fish showed that the diges- tive enzymes were qualitatively similar … 相似文献
135.
机载LIDAR数据的树高识别算法与应用分析 总被引:1,自引:0,他引:1
利用机载激光雷达数据提取天然次生林的树高,旨在探索影响树高提取精度的主要因素。首先,采用高精度曲面建模平差算法(Adjustment Computation of High-accuracy Surface Modeling,HASM-AD)生成研究区不同空间分辨率的数字高程模型(Digital Elevation Model,DEM)、数字地表模型(Digital Surface Model,DSM)和冠层高度模型(Canopy Height Model,CHM);其次,用树顶点识别算法提取林木树高,设置不同树高识别范围,对比分析不同CHM分辨率和不同树高识别范围对树高提取精度的影响;最后,以天涝池流域30个实测样地数据为样本,对提取精度进行检验。结果显示:提取的样地平均树高与实测值具有明显线性相关关系,线性回归系数为0.694;树高识别范围是影响树高提取精度的重要因素,CHM分辨率对其影响较小。研究表明,采用高采样密度的雷达点云数据、正确选择CHM生成方法和改进树顶点识别算法是提高天然次生林树高提取精度的有效途径。 相似文献
136.
Binbin Shan Yan Liu Na Song Changping Yang Shengnan Liu Tianxiang Gao Dianrong Sun 《海洋学报(英文版)》2021,40(6):41-49
The stock enhancement programs for black sea bream Acanthopagrus schlegelii have been conducted in China for a fewyears.However,little information has been reported concerning the effectiveness and genetic effect of black sea bream stock enhancement.In order to detect the contribution of released individuals in Zhujiang River Estuary(ZRE) and Daya Bay(DB),six microsatellite markers were used to identify the hatchery-released individuals.In addition,this pedigree of hatchery populations(broodfish and hatchery-released offspring) was traced to detect the number of effective parents(N_e),the inbreeding coefficient and the decrease of genetic variability in the reproduction.The pedigree reconstruction showed that at least 69(out of 93) broodfish had offspring.The estimated N_e was 54.8,consequently the inbreeding coefficient was 0.91%.The genetic diversity of hatchery-released offspring was lower than that in that of broodfish(heterozygosity alleles,0.727-0.774),some alleles(number of alleles,61-69) and genetic variance were lost during reproduction.It was observed that wild samples had higher levels of genetic diversity compared with hatchery populations as well as recaptured samples in releasing area.A total of 128 hatchery-released black sea bream were identified among 487 recaptured samples in ZRE,while a total of 15 samples were identified among 96 samples in DB.In summary,there was a high survival of released fish.Nevertheless,the results provided evidence to consider a loss of genetic variation in hatcheryreleased stock and a negative genetic effect of the stock enhancement. 相似文献
137.
基于Landsat ETM+数据的白龙江流域土壤水分反演 总被引:3,自引:0,他引:3
在地形复杂、水土流失严重且地质灾害严重的白龙江流域,土壤含水量遥感监测在地质灾害监测预警研究中具有重要意义。为实时掌握白龙江流域的土壤水分含量状况,利用2013年4月的Landsat7 ETM+影像,采用温度植被干旱指数法,构建Ts-NDVI特征空间,结合野外88个实测样点土壤水分数据,建立0~60 cm土壤深度范围内3个单层(0~20 cm,20~40 cm,40~60 cm)及2个平均层(0~40 cm,0~60 cm)的土壤水分遥感反演回归模型,对比分析了白龙江流域5个深度的土壤水分的空间变化特征,并用未参与建模的16个实测土壤水分数据样点进行相应的精度验证。结果表明:3个单层中20~40 cm土壤水分反演精度相对较高,RMSE值为3.06%,2个平均层中0~40 cm反演精度最高(RMSE)为2.45%,由此说明TVDI更能稳定地反映和指示土壤中层深度(20~40 cm)的水分分布状况。 相似文献
138.
Forest vegetation carbon patterns are significant for evaluating carbon emission and accumulation. Many methods were used to simulate patterns of forest vegetation carbon stock in previous studies, however, uncertainty apparently existed between results of different methods, even estimates of same method in different studies. Three previous methods, including Atmosphere-vegetation interaction model 2(AVIM2), Kriging, Satellite-data Based Approach(SBA), and a new method, High Accuracy Surface Modeling(HASM), were used to simulate forest vegetation carbon stock patterns in Jiangxi Province in China. Cross-validation was used to evaluate methods. The uncertainty and applicability of the four methods on provincial scale were analyzed and discussed. The results showed that HASM had the highest accuracy, which improved by 50.66%, 33.37% and 28.58%, compared with AVIM2, Kriging and SBA, respectively. Uncertainty of simulation of forest biomass carbon stock was mainly derived from modeling error, sampling error and statistical error of forest area. Total forest carbon stock, carbon density and forest area of Jiangxi were 288.62 Tg, 3.06 kg/m~2 and 94.32×109 m~2 simulated by HASM, respectively. 相似文献
139.
140.
Regional geochemical surveys in arid and semiarid regions in the middle and western part of Inner Mongolia 总被引:1,自引:0,他引:1
For many years the results of regional geochemical surveys in arid and semiarid regions of China were not satisfactory. Therefore, we selected eight areas in the middle and western part of Inner Mongolia and the northwestern part of Gansu Province to study this problem from 1982 to 1985. The contents of our study include: the migration and distribution of elements in an arid environment; the interference of aeolian sand; the applicability of different sampling mediums; and the development of effective sampling techniques. Pilot surveys were carried out covering several hundred or more than a thousand square kilometres in every test area after the orientation study.Very good results were obtained in the surveys carried out in mountainous and hilly regions. The only problem was to eliminate effectively the interference of aeolian sand. To accomplish this we collected elastics of −5 + 2 mm or − 10 + 0.9 mm coarse grain size in the dry valley. In the stony Gobi desert region and the eroded peneplain region, a rock survey and residual soil survey produced the results expected. However, we had to consider the following influencing factors: (1) the caliche in the loose soil layer forms a barrier, hindering the migration of most of the elements in a vertical direction. Only where the caliche was rather thin was the influence of little significance; (2) in the residual soil of the background area and non-mineralized zone, almost all trace elements are enriched secondarily. The enrichment factors are generally between 1.3 and 1.8. In the residual soil of the mineralized zone, almost all ore-forming elements are impoverished. The well-water geochemical survey and the deep-root system plant survey have a peculiar function in finding ore deposits in the arid region. These two methods are discussed elsewhere. 相似文献