【作者】 白云飞；

【导师】 吴婷婷；

【作者基本信息】 南京农业大学 ， 水产养殖， 2001， 硕士

【摘要】 1、用RAPD技术对四种不同地区罗非鱼进行种群遗传结构差异性分析和杂种优势的预测。 在20条随机引物中，筛选到12条引物对四种不同地区的罗非鱼：淡水渔业中心奥利亚罗非鱼（83淡奥利亚）、沙市尼罗罗非鱼（78沙尼罗）、埃及尼罗罗非鱼（99埃及尼罗）、埃及奥利亚罗非鱼（99埃及奥利亚）进行RAPD扩增，均得到1-8个大小不等的DNA片段，长度大部分在500-2300bp之间。同时构建了这四种罗非鱼的基因组指纹图谱，通过对获得的基因组指纹图谱进行种群结构差异性分析，利用UPGMA构建它们之间的遗传距离树状图。结果表明：83淡奥利亚、78沙尼罗、99埃及尼罗、99埃及奥利亚四种罗非鱼种内相似系数分别为0.853、0.706、0.592、0.667；83淡奥利亚与78沙尼罗、99埃及尼罗及99埃及奥利亚群体间遗传距离分别为0.577、0.450、0.386；78沙尼罗与99埃及尼罗及99埃及奥利亚群体间遗传距离分别为0.368和0.466；99淡尼罗与99埃及奥利亚群体间遗传距离为0.400。这说明淡水中心奥利亚罗非鱼的种质最纯，接近一个超纯体，沙市尼罗罗非鱼次之，但也具有相当高的纯度，埃及尼罗罗非鱼和奥利亚罗非鱼种内还具有相当大的遗传变性，指出二者种内还具有较大的选择空间，在经过不断的科学选育之后，可以作为较好的选育资源加以利用。同时根据遗传距离大小可预测83淡奥利亚（♂）和78沙尼罗（♀）之间能产生比78沙尼罗（♀）和99埃及奥利亚（♂）更强的杂交优势。2、对四种不同地区罗非鱼进行传统的形态学差异分析。 对四种不同地区的罗非鱼通过传统形态学测定与可比性状相结合，用方差分析进行群体形态学差异显著性研究，同时利用柱状分析图对四种罗非鱼的四个可比性状参数进行比较分析。可数性状分析结果表明，这几种罗非鱼在可数性状上无显著性差异。可比性状在整体上分析也无显著性差异。但对四种罗非鱼可比性状的四个参数进行分析，结果表明，四种罗非鱼在某些可比性状上（体长/体高、 摘 要体长／头长、头长／尾柄长、头长／尾柄高）具有显著性差异，埃及的两种罗非鱼在体形上都要比淡水中心奥利亚罗非鱼和沙市尼罗罗非鱼偏长。这可能由以下两种原因造成：①不同地埋种群受环境因子的影响而造成形态上的差异；②人们在鱼类选育目的上的不同对罗非鱼形态上的差异也有很大的影响。更多还原

【Abstract】 1. RAPD technique was used to analyze the genetic structure and forecast fish heterosis of four different areas of tilapia populations. In all 20 random primers, 12 random primers were chosen out and used to amplified the individuals?genomic DNA of four Tilapia populations (Fo is token FFRC O.uureus, Sn: Shashi O.niloticus; En: Egyptian O.niloticus; Eo: Egyptian O.uure us). The 12 primers all generated amplification bands, whose numbers ranged from I to 8 and sizes from 500-2300bp. By analyzing the data of the genetic fingerprints, the genetic relationship of the four tilapia populations was constructed with UPGMA. The result of this experiment showed the fact as follow: the with-population index of similarity of Fo, Sn, En and Eo calculated from RAPD fingerprints were respectively 0.853,0.706,0.592 and 0.667.The between-population index of genetic distance of them were that Fo and Sn was 0.577, Fo and En was 0.450, Fo and Eo was 0.386, Sn and En was 0.368, Sn and Eo was 0.466. En and Eo was 0.400. From the data it was safely to arrive the conclusion that the genetic quality of Fo was more pure than the rest of the four populations?and there were still some genetic diversity of En and Eo. It suggested that if they were chosen properly, they were all good breeding resources. At the same time, according to the data of between-population 3 ABSTRACT index of genetic distance, it could be predicted that Fo( ~ ) X Sn( ~) should have a more advanced beterosis. 2. 11aditional morphological data was used to analyze the morphological variations of the four tilapia populations from different areas. Traditional morphological data and comparable characters were combined to conduct a multivariation analysis to study the morphological variations of four tilapia populations. Analysis of meristic characters and comparable characters in whole indicated that there were no significant differences among these populations, but in the comparable characters, there were four parameters among the four populations existed significant differences. From the result, it could be informed that the two Egyptian populations were longer than the others in length. It was caused possibly by the following two reasons: CD Different geographic populations were undergone different circumstance factors;甌he select tendency of local people were also very important.更多还原