【作者】 王坤；

【导师】 凌去非；

【作者基本信息】 苏州大学 ， 水产养殖， 2009， 硕士

【摘要】 泥鳅(Misgurnus anguillicaudatus)属鲤形目、鳅科、花鳅亚科、泥鳅属,是近年来国内外市场需求量不断上升的淡水鱼类之一,而且泥鳅因其适应性强、疾病少、成活率高、运输方便等特点,已成为重要的水产养殖对象。然而,目前用于泥鳅养殖的苗种主要是从天然水域中进行捕捞,来源不同的泥鳅其遗传背景不同,生长性能也不尽相同,给生产管理造成了极大的压力。本研究对长江流域6个不同泥鳅群体的分子遗传学和生长性能进行研究,并对苏州地区泥鳅和大鳞副泥鳅的年龄与生长进行了比较,为进一步开展泥鳅的种质资源保护和遗传育种工作提供理论指导。主要结果如下:1长江流域不同泥鳅群体遗传差异的SSR分析利用9对微卫星引物对我长江流域泥鳅苏州群体(SZ)、高邮群体(GY)、安徽群体(AH)、湖南群体(HN)、湖北群体(HB)、江西群体(JX)等6个野生泥鳅群体的观测杂合度(HO)、期望杂合度(He)、多态信息含量(PIC)和平均有效等位基因数(Ne)等进行了遗传检测,根据基因频率计算遗传相似系数和Nei氏标准遗传距离,χ2检验估计Hardy– Weinberg平衡,用遗传分化系数(Fst)和基因流(Nm)分析群体的遗传分化及其来源。同时,使用MEGA 3.1软件绘制基于Nei氏标准遗传距离的UPGMA进化树。6个群体共检测到352个片段,长度在105-383bp,多态位点上扩增出的等位基因数目从1到4个不等, 9对微卫星引物共检测到27个等位基因,平均等位基因数为3。统计结果显示:(1)6个野生泥鳅群体的多态性指标均处于中等偏低水平,平均多态信息含量分别为0.2731、0.3928、0.3906、0.2901、0.3351和0.2319,平均有效等位基因数依次为1.5881、1.9577、2.0336、1.6305、1.7652和1.5124,无偏期望杂合度平均值为0.3130、0.4614、0.4658、0.3641、0.4019和0.2866;(2)泥鳅群体间的遗传分化明显,各基因座遗传分化系数的均值为0.2147,基因流的均值为0.9146;(3)遗传相似系数江西群体与湖南群体最高(0.9535),苏州群体与江西群体最低(0.5804),6个泥鳅群体的聚类分析结果与地理分布呈一定相的关性。2长江流域不同泥鳅群体的生长性能比较2008年8月2日至12月4日,对苏州(SZ)、高邮(GY)、安徽(AH)、江西(JX)、湖南(HN)、湖北(HB)等6个泥鳅群体的各个自繁子一代和苏州群体(♀)×高邮群体(♂)的繁殖子一代(GS)进行了为期124d的生长对比试验。结果表明:(1)绝对增重率(g/d):GS﹥SZ﹥GY﹥AH﹥HN﹥HB﹥JX,GS比GY、SZ分别提高了16.7%、14.0%,GS与其它泥鳅群体的绝对增重率均存在极显著的差异(P﹤0.01),GY和SZ两个群体间的绝对增重率差异不显著(P﹥0.05),且高于AH、JX、HN和HB 4个群体;(2)体重变异系数(%):HN﹥HB﹥JX﹥AH﹥GY﹥GS﹥SZ,SZ的体重变异系数最低(5.75%),JX、AH、HN和HB 4个群体的体重变异系数均高于GS和GY两个群体;(3)成活率:SZ﹥GS﹥GY﹥AH﹥HN﹥JX﹥HB,其中,SZ的平均存活率最高(96.7%),HB的最低(86.0%),SZ、GS与GY三者之间成活率的差异不显著(P﹥0.05)。总之,依据生长性能和成活率评价,在苏州现有的环境条件下,SZ与GY两个泥鳅群体均表现出优良的养殖性能。苏州群体(♀)×高邮群体(♂)群体间繁殖的子一代GS的生长性能超过了其父、母本群体,显示了较好的养殖潜力。3泥鳅和大鳞副泥鳅年龄与生长的初步研究选取鳞片作为苏州地区泥鳅和大鳞副泥鳅的年龄鉴定材料,并对两种鱼进行了常规生物学测定。结果显示,泥鳅和大鳞副泥鳅的体长与鳞径均呈直线相关,其相关式分别为泥鳅L = 99.577R + 9.7435(r = 0.997);大鳞副泥鳅L = 74.445R + 9.6442(r = 0.995)。两种鱼体长与体重均呈幂函数关系,相关式分别为泥鳅W = 0.0118L2.8644(r = 0.899)和大鳞副泥鳅W = 0.0146L2.8135(r = 0.923)。体长、体重的生长规律能较好地用Von Bertalanffy方程进行拟合(P﹤0.01),其表达式分别为泥鳅:L t = 25.90[1-e-0.191(t+0.806)],Wt = 135.90[1-e-0.191(t+0.806)]3;大鳞副泥鳅:Lt = 25.59[1-e-0.201(t+0.731)];Wt = 169.45[1-e-0.201(t+0.731)]3。3龄以前两种鱼的体长生长速度较快,两种鱼的体重生长拐点年龄分别为4.95龄和4.73龄。更多还原

【Abstract】 Loach(Misgurnus anguillicaudatus)belongs to Cypriniformes、Cobutudae、Cobitinae、Misgurnus, it is one of the freshwater fish which is very popular in domestic and foreign markets in recent years, and it has become an important object of aquaculture because of its character of good adaptability、less disease、high survive rate and convenient transportation. But, the fry used in the loach cultivation mostly come form natural waters at the present time, the genetic backgrounds and the growth-performance of different loach populations are not the same, and it has become tremendous pressure to the producton management. In this sdudy, the SSR genetic marks and the growth-performance of different loach populations in the Yangtae River Basin were analyzed comprehensively, and the age and growth of Misgurnus anguillicaudatus and Paramisgurnus dabryanus was studied, providing essential throretical support for further study of germplasm resources protection and genetic breeding. The major results are as following:1. Microsatellite DNA Marker Analysis of Genetic Diversity of the Loach (Misgurnus anguillicaudatus) Populations in the Yangtze River BasinNine microsatellite loci were used for analyzing six wild loach populations(Suzhou population, SZ、Gaoyou population, GY、Anhui population, AH、Hunan population, HN、Hubei populations, HN、Jiangxi population, JX), Observed (HO) and expected (He) heterozygosity values, polymorphic information content (PIC) , and number of effective alleles (Ne) were all detected. Genetic similarity index and genetic distance were computed based on the allele frequency. The Hardy-Weinberg Equilibrium was checked according to the test ofχ2. Genetic differentiation and hierarchical partition of genetic diversity were evaluated by Fst and Nm. A clustering dendrogram was made based on the results of UPGMA methods using MEGA 3.1 software. There were totally 352 fragments ranging from 105bp to 383bp in length. 1 to 4 alleles were amplified at the nine loci and 27 alleles in all 6 loach populations. The average number of alleles in each locus was 3. The results showed that:(1)The level of genetic variability was relatively low in the six populations. Polymorphic information contents of the six wild loach populations were 0.2731、0.3928、0.3906、0.2901、0.3351 and 0.2319 respectively. The average numbers of effective alleles were 1.5881、1.9577、2.0336、1.6305、1.7652 and 1.5124. The average expected heterozygosity values were 0.3130、0.4614、0.4658、0.3641、0.4019 and 0.2866 respectively;(2)The genetic differentiation of 6 loach populations was obvious, the average value of coefficient of genetic differentiation for all loci was 0.2147, and the average valure of gene flow(Nm) was 0.9146.(3)The highest genetic similarity index that came form the populations of JX and HN was 0.9535, the lowest index was 0.5804, and it came form the populations of SZ and JX. There was a certain correlation between the clustering result and the geographical distribution.2. Comparison of Growth-Performance of different Loach (Misgurnus anguillicaudatus) Populations in the Yangtze River BasinThe comparative experiments of growth of loach offsprings of Suzhou population (SZ)、Gaoyou population (GY)、Anhui population (AH)、Jiangxi population(JX)、Hunan population(HN)、Hubei population(sHN) and Suzhou population (♀)×Gaoyou population(♂)(GS)were proceeded during 124 days from August 2th to November 4th in 2008:(1)Absolute growth rate(g/d): GS﹥SZ﹥GY﹥AH﹥HN﹥HB﹥JX, GS was 16.7%、14.0% higher than GY and SZ respectively, there was most significant differences between GY and other six loach populations(P﹤0.01), the difference between GY and SZ is not signidicant, and the absolute growth rate of the two population are higher than that of AH、JX、HN and HB.(2)Variation coefficients of body weigh(t%): HN﹥HB﹥JX﹥AH﹥GY﹥GS﹥SZ, the variation coefficients of body weight of SZ was the lowest, and the varitation coefficients of JX、AH、HN and HB were higher than that of GY and GY.(3)Survival rates(%): SZ﹥GS﹥GY﹥AH﹥HN﹥JX﹥HB, thereinto, the average survival rate of SZ was the highest(96.7%), and that of HB was the lowest(86.0%), there were significant differences between any one of four loach populations and GS(P﹤0.05) except GY and SZ(P﹥0.05). In a word, based on the evaluation of growth performance and survival rate, the GY and SZ all shows excellent cultivation performances in the current environmental conditions of Suzhou. The growth performance of GS is superior to its parent populations, and shows better cultural potential.3. Primary stydy on the age and growth of the loach ( Misgurnus anguillicadudatus)and large scale loach (Paramisgurnus dabryanus)The scale was choosed as age identification materials of Misgurnus anguillicaudatus and Paramisgurnus dabryanus, and the two kinds of fish were determined by the conventional biology methods. The results showed that the relationships between the body length and the scale radius of Misgurnus anguillicaudatus and Paramsigurnus dabryanus is beeline correlative and the expressionses were L = 99.577R + 9.7435(r = 0.997)and L = 74.445R + 9.6442(r = 0.995). The growth trait of the length and weight of these two fishes was similar: W = 0.0118L2.8644(r = 0.899); W = 0.0146L2.8135(r = 0.923). The body groth pattern can be well described by Von Bertallanffy equation(P﹤0.01)and they were Misgurnus anguillicaudatus: Lt = 25.90[1-e-0.191(t+0.806)], Wt = 135.90[1-e-0.191(t+0.806)]3 and Paramsigurnus dabryanus: Lt = 25.59[1-e-0.201(t+0.731)], Wt = 169.45[1-e-0.201(t+0.731)]3。The stage before the age of 3 was a speediness growth phase of body length. The ages of growth turning point of body weight of the two fishes were 4.95 years and 4.73 years respectively.更多还原