【作者】 肖慧；

【导师】 毛慧玲；

【作者基本信息】 南昌大学 ， 生物化学与分子生物学， 2011， 硕士

【摘要】 黄颡鱼属(Peletoagrus)隶属于硬骨鱼纲,鲶形目(siluriofmres),鲿科(Bagridae)。为一种小型名优经济鱼类,广受消费者喜欢。江西境内有赣江、抚河、信江、饶河、修河等五大流域,五河流域汇聚了江西省境内的绝大部分地表径流并最终流入鄱阳湖。境内的鄱阳湖是中国最大的淡水湖泊,也是目前仅存的两个通江湖泊之一,蕴含着丰富的渔业资源。目前关于黄颡鱼的研究主要集中在长江流域、武汉等地,较少见关于江西水域黄颡鱼的相关研究报道。鄱阳湖“五河”地形独特,地理环境不同,是研究黄颡鱼的良好场所。本论文以广布种普通黄颡鱼(Pelteobagrus fulvidraco)为材料,从形态、分子遗传学两方面来对江西水域不同群体普通黄颡鱼展开相关研究,旨在为黄颡鱼的保护和合理开发利用,良种的选育提供一手资料和科学指导。1黄颡鱼种质资源普查于2009.05-2010.10期间对江西五大河流和鄱阳湖水域进行全面的黄颡鱼种质资源调查。共在14个采样点,获得862尾野生黄颡鱼。结果显示,江西水域黄颡鱼种质资源还是较为丰富,尚处安全状态,但是黄颡鱼呈现低龄化的情况应该引起我们的关注和采取相应的应对措施。普通黄颡鱼(Pelteobagrus fulvidraco)在江西五大河流和鄱阳湖水域均有分布,且数量众多；而在万安、湖口还发现有瓦氏黄颡鱼(Peheobagrus Vachell)的分布,尤其是在湖口地区瓦氏黄颡鱼体重明显大于普通黄颡鱼,赣州有长须黄颡鱼(Pelteobagrus eupogon)的分布,南昌有光泽黄颡鱼(Pseudobagrus nitidus)的分布。湖口为黄颡鱼种质资源最丰富的地区。此次黄颡鱼分布调查结果与褚新洛(1999)在中国动物志——硬骨鱼纲(鲇形目)中描述的黄颡鱼分布结果较为接近。同时发现,近年来因为人工过度捕捞,河道内采沙船的滥挖,使得黄颡鱼的产卵地遭到破坏,已经出现严重的黄颡鱼小龄化情况,有必要引起相关部门的重视,采取相应的保护及应对措施。2不同群体黄颡鱼形态分化比较本研究采用聚类分析、判别分析、主成分分析等多元统计分析方法,从形态学角度阐述江西境内9个野生普通黄颡鱼群体间的形态分化,并对其进行分析,同时选取了一个养殖群体作为对照。其结论如下：对可量性状多元分析发现普通黄颡鱼不同群体外部形态差异明显。聚类分析显示,9个群体普通黄颡鱼可分为3支：鄱阳、永修、抚州、余干4个群体聚为一支；南昌、赣州、峡江、万安群体聚为一支；湖口距离最远,单独聚为一支。作为对照的养殖群体,在遗传距离上介于湖口与万安之间。主成分分析反映,湖口群体差异最显著,万安次之。判别分析发现,建立的判别函数综合辨别率达81.67%,交互验证后达77.49%。上述3种多元分析结果表明,江西水域9个普通黄颡鱼群体在形态上已产生了一定程度的分化,且集中表现在头部与尾部纵向长短指标上,尤其是湖口、万安群体差异最显著。这种形态上的分化更多的是为了适应其独特的生活习性以及所处的水域环境造成的。3黄颡鱼遗传多样性分析利用前人已开发出来的12对黄颡鱼SSR引物,对赣州(GZ)、万安(WAN)、湖口(HK)3个野生普通黄颡鱼群体进行了遗传多样性分析。将12对SSR引物通过优化反应条件筛选,获得10对有效引物,7个微卫星位点,且都具有多态性。7个微卫星位点上检测出103个等位基因,每个位点的等位基因数2-8个不等,大小在84-280bp之间。3个群体的平均观察杂合度为(He)0.62,其中HK群体最高(0.6509),GZ群体次之(0.6209),WAN最小(0.5882)。3个群体的平均PIC为0.5633.其中GZ群体为：0.5618,HK群体为0.5944,WAN群体为0.5336。WAN与GZ遗传相似指数最高为0.7314,遗传距离最小0.3128；GZ与湖口的遗传相似指数、遗传距离居中。WAN与HK群体遗传相似指数最小0.7002,遗传距离最大0.3517.由此可推断WAN与GZ亲缘关系较为接近,WAN与HK群体亲缘关系最远。SSR分析结果表明,目前赣江和湖口水域黄颡鱼种质资源尚处于安全状态,遗传多样性丰富程度较高。各项遗传多样性指标接近或者略高于已报道的别的水域黄颡鱼群体。而万安群体由于长期的地理隔离,遗传多样性已有所降低,有必要引起我们的重视,采取相应的措施以防止这一情况继续恶化,更好的维系黄颡鱼的种质资源安全。更多还原

【Abstract】 Genus Pelteobagrus belongs to Osteichtliyes, Siluriofmres, Bagrida. As a kind of small and famous economic fish, Pelteobagrus is well accepted by consumers. There are five rivers in Jiangxi Province which are Gan River、Fu Rive、Xinjiang River、Rao River、Xiu River. Five rivers gather together the majority of surface runoff in Jiangxi Province and flow into the Poyang Lake which is the largest fresh lake in China and is one of the two biggest lakes still linked with the Yangtze River, so it contains the rich fish resource. At the present time, researches of P. fulvidraco are concentrated in area of Yangtze River and Hubei province. The reports of P. fulvidraco in Jiangxi water area are few. The unique topography of Poyang Lake’s "five rivers" and different geographic environment provide good places to study P. fulvidraco. The research of different groups of P. fulvidraco in Jiangxi water area on this paper is based on morphology and molecular genetics. So it can provide primary data and scientific guidance for Pelteobagrus’s protection reasonable exploitation and breeding improved varieties.1:Investigation of Pelteobagrus’s germplasm resourcesWe have made a complete investigation of Pelteobagrus’s germplasm resources in five rivers and Poyang Lake during 2009.05-2010.10. We got 862 wild Pelteobagrus in 14 sample pointsThe result shows that Pelteobagrus’s germplasm resources in Jiangxi water area are relatively rich and safe, but we should pay attention to the trend of lower age and take any appropriate action. A number of Pimelodus fulvidiraco distribute in five rivers and Poyang Lake. We find Bagrus vachelli in Wanan and Hukou, the size of Bagrus vachelli is much bigger than Pimelodus fulvidiraco in Hukou. We also find Pseudobagrus eupogon in Ganzhou and Pseudobagrus nitidus in Nanchang. Pelteobagrus’s germplasm resources are the mostly rich in Hukou. The result of this investigation of Pelteobagrus’s germplasm resources is similar to what Zhu Xinluo (1999) wrote in Fauna Sinica, Osteichthyes, Siluriformes. Meanwhile, it was discovered that destruction of Pelteobagrus’s spawning grounds and the trend of lower age were primarily due to over-fishing and abuse of Schwimmbagger. It is necessary to pay attention and adopt corresponding protection and measures.2:Comparison of morphological differentiation between different groups of PelteobagrusThis study use multivariate statistical analysis which are cluster analysis, discriminant analysis and principal component analysis to elaborate the morphological differentiation of nine wild Pelteobagrus populations in Jiangxi province from morphological and analyze the causes. At the same time, we also choose a breeding population to compare. The conclusions are as follows:Obvious morphological differences can be found in different Pelteobagrus groups by using multivariate analysis to analyse measurable character. Cluster analysis shows that nine populations can be divided into three groups:the first group include Poyang、Yongxiu、Fuzhou and Yugan because the genetic distance between them are small. So is the second group which include Nanchang、Ganzhou、Xiajiang and Wanan. The third group is Hukou because of its large genetic distance. The breeding population’s genetic distance is between Hukou and Wanan. Principal component analysis shows group differences of Hukou are the most notable, next is Wanan. Discriminant analysis finds that comprehensive identification rate of discriminant function is 81.67%, it can get 77.49% after cross-validation. The result showed by three kinds of multivariate analysis indicate that nine Pelteobagrus populations in Jixangxi water area exist morphological differentiation among the individuals to a certain extent, focusing on the index of lengthways length of head and tail, especially for Hukou and Wanan populations. In order to adapt the geographic isolation water environment, Pelteobagrus appeared the morphological differentiation.3:Researches on the genetic diversity of P. fulvidracoWe have done some researches on the genetic diversity of three wild P. fulvidraco populations which were GZ、WAN and HK by using 12 pairs of SSR primers of P. fulvidraco which had been exploited by other scholars. The results are as follows:By optimizing the reaction conditions, we find 10 of 12 pairs of SSR primers are effective and get 7 microsatellite locis which all have polymorphism.48 alleles were detected from 7 microsatellite locis. The size of each microsatellite loci which has 2-8 alleles is between 84-280bp. Average observed heterozygosity of three populations is 0.62, the highest one is HK (0.6509), the next is GZ (0.6209), the last one is WAN (0.5882). Average PIC of three populations is 0.5633,GZ (0.5618)、HK (0.5944、WAN(0.5336). We found that genetic similarity index was 0.7314 between WAN and GZ which was the highest and genetic distance is 0.3128 which was the lowest. Genetic similarity index and genetic distance was the second between GZ and HK. Genetic similarity index which was 0.7002 between WAN and GZ was the lowest and genetic distance which was 0.3517 was the highest. So we can make an inference that there was a closer genetic relationship between WAN and GZ, while genetic relationship between WAN and HK was furthest.The result of SSR showed Pelteobagrus’s germplasm resources in GZ and HK water area were still in safe and genetic diversity was rich. Indexes of genetic diversity were close to or slightly higher than other populations which had reported. As building-up of Wanan hydropower station caused the long-term geographical isolation, WAN population’s germplasm resource is decreasing. So corresponding protection and measures should be done to keep the germplasm resources of Pelteobagrus.更多还原