【作者】 佟雪红；

【导师】 缪为民；

【作者基本信息】 南京农业大学 ， 水产养殖， 2007， 硕士

【摘要】 杂交育种是目前提供良种的有效途径，国内外的育种大多以经济杂交（即杂种优势利用）为主。建鲤是我国第一个人工育成的优良鲤鱼品种，遗传性状稳定，比其他鲤鱼能普遍增产30％以上。建鲤育成和大面积推广已经十多年，需要通过不断的遗传改良和选育来保持和提高其优良性状。黄河鲤是我国北方的一个地方良种，具有肉质鲜美、抗寒能力强和饲料转化效率高的特点。本研究进行了建鲤自交及建鲤与黄河鲤的正、反杂交试验，对子代的杂种优势及相关的分子生物学进行了分析和研究，籍此为建鲤性状的改良和培育品质更加优良的鲤鱼新品种提供理论指导。研究内容包括：生长比较试验、生长性状的通径分析及子代基因组DNA的遗传差异分析。1．生长比较试验采用个体标记后的混合养殖试验比较了子代的生长率。157日龄和398日龄测定时，子代群体的绝对增重率、特定生长率均为HJ（黄河鲤♀×建鲤♂）＞JH（建鲤♀×黄河鲤♂）＞JL（建鲤♀×建鲤♂），各群体中雌、雄鱼的增重率也遵循这样的规律；598日龄时子代的绝对增重率为JL＞JH＞HJ，JL（♀）＞JH（♀）＞HJ（♀），JH（♂）＞JL（♂）＞HJ（♂）；JL在后期的生长优势最大且优势主要表现在群体中的雌鱼。试验中雌鱼、雄鱼间生长差异显著，JH（♀）、HJ（♀）一直有优势，JH（♂）、HJ（♂）仅在157日龄测定时有优势，所以JH、HJ的生长优势主要表现在398日龄前，且优势主要表现在群体中的雌鱼。群体的肥满度均随日龄增加而增大，在各个时期均以JL最高。157、398日龄时各群体的肥满度大小为JL＞HJ＞JH；598日龄时JL＞JH＞HJ。雌、雄鱼的肥满度均以JL最高。各群体157和398日龄时体长变异系数、体重变异系数的大小均为HJ＞JH＞JL；598日龄时JL＞HJ＞JH。不同日龄时的体长变异系数均小于体重变异系数。子代的生长指标均随日龄增加而增大，398、598日龄时以HJ最大。试验过程中，雌鱼的生长指标均大于雄鱼。2．生长性状的通径分析体长-体重相关系数和体高-体重相关系数随日龄增加均呈下降趋势。通径分析表明，对儿、HJ而言，398日龄时，体长对体重的决定系数大于体高的决定系数，优势性状为体长；598日龄时，优势性状为体高。对JH而言，体长对体重的决定系数始终大于体高的决定系数。就雌、雄鱼而言，398日龄时体长对体重的决定系数均大于体高的决定系数，优势性状为体长；598日龄时，HJ（♀）和JL（♀）的优势性状为体高，JL（♂）、HJ（♂）和JH（♀）的优势性状为体长，JH（♂）中体长、体高对体重的决定系数差异很小。体长和体高对体重的决定系数是子代杂种优势差异的重要原因。3．基因组DNA的遗传差异分析采用40个随机引物对建鲤、黄河鲤、正交F₁、反交F₁四个群体基因组DNA进行了RAPD分析。结果表明，筛选的33个引物共扩增出155条带，其中105条为多态性条带；引物S472、S18、S478在建鲤上扩增出了与黄河鲤相区别的片断：S18-₁₆₀₀，S472-₃₀₀，S478-₉₅₀，可作为鉴别这两群体的特异分子标记。建鲤、黄河鲤、正交F₁与反交F₁的多态位点比例分别为：37.33％、42.38％、47.33％、33.33％；建鲤、黄河鲤、正交F₁与反交F₁群体内的遗传相似系数分别为0.8240、0.7921、0.7920、0.8596；基因多样性指数和香农指数的大小程度均为正交F₁＞黄河鲤＞建鲤＞反交F₁，黄河鲤与正交F₁具有较高的遗传变异水平，反交F₁变异最小。正交F₁与亲本（建鲤、黄河鲤）的遗传距离分别为0.2233、0.2436，反交F₁与亲本（建鲤、黄河鲤）的遗传距离分别为0.1749、0.2026，说明JH、HJ均继承了较多JL的遗传物质。子代与亲本的RAPD图谱变化主要有4种类型，这些变化若是与某些经济性状相关，则这种DNA序列的差异就是杂种优势产生及强度变化的基础。本试验中，杂种优势的表现与后代的生长阶段有关，分析了影响杂种优势的可能原因，以期为养殖生产提供一定的理论指导。更多还原

【Abstract】 At present, hybridization is an effective method for developing a fine breed. Economical hybridization （i. e. utilization of heterosis） had been taken as main approach in breeding work conducted in China and abroad. Jian carp（Cyprinus Carpio Var. jian） was the first artificially developed fine breed of common carp with stabilized genetic attributes in China. 30% higher production could be obtained under the same culture method compared with other common carp varieties. Jian carp had been disseminated in large scale for more than a decade, there was a great need to maintain and enhance its fine production related traits through continuous selection and genetic improvement. Huanghe carp（Cyprinus carpio haematopterus Teminck et Schlegel） was a remarkable variety of common carp in northern China, which possessed fine traits such as good meat quality, strong cold resistance and high efficiency of food conversion. In order to provide theoretical guidance for improvement of Jian carp and development of new carp species, self-cross of Jian carp and direct and reciprocal cross between Jian carp and Huanghe carp were conducted. Heterosis of offspring and related molecular biology were compared and studied. This thesis study covered the following aspects: growth comparison, path analysis of growth traits and genetic variation analysis of genome DNA of offspring.1. Growth comparisonGrowth rates of offspring from different crosses were compared through communal rearing test with PIT tagged individuals. Comparison of growth performance was conducted for Jian carp and F₁ hybrids of Jian carp and Huanghe carp. The results showed the growth rate of body weight before the age of 157 d and 398 d of different crosses were HJ（Huanghe carp♀×Jian carp♂）＞JH（Jian carp♀×Huanghe carp♂）＞JL（Jian carp♀×Jian carp♂）. Both male and female fishes showed the same results during this period. At the age of 598 d, absolute growth rate of body weight of different crosses were respectively JL＞JH＞HJ, JL（♀）＞JH（♀）＞HJ（♀）, JH（♂）＞JL（♂）＞HJ（♂） and the superiority of JL in growth contributed mainly by the female carps was the highest among the offspring. The growth difference between female carps and male ones were significantly different. JH（♀） and HJ（♀） showed the heterosis throughout the cultivation period, while heterosis was maintained only before the age of 157 d in JH（♂） and HJ（♂）. So heterosis of JH and HJ was mainly observed before the age of 398 d and it was largely contributed by female individuals.The fullness of individuals in the populations increased along with age. JL showed highest degree of fullnesss over other F₁ hybrids throughout the experiment period. At the age of 157 d and 398 d, the degree of fullness of different crosses was JL＞HJ＞JH. At the age of 598 d, it was JL＞JH＞HJ. JL maintained the highest fullness in both male and female individuals too.Variation coefficient of body length and body weight of different crosses was HJ＞JH＞JL at the age of 157 d and 398 d and HJ＞JH＞JL at the age of 598 d. The result also showed that variation coefficient of boby length was smaller than that of body weight. The growth index had the trend to increase with the age of fishes. HJ had the highest growth index at the age of 398 d and 598 d. In the experiment, the female individuals always showed higher growth index than the male ones.2. Path analysis on growth traitsCorrelation coefficients of body length to body weight and body height to body weight declined with age of fishes. Path analysis revealed that determination coefficient of body length to body weight was higher than that of body height to body weight in JL and HJ at the age of 398 d, which suggested body length was a dominant trait. Body height became the dominant trait for JL and HJ at the age of 598 d. Determination coefficient of body length to body weight was higher than that of body height to body weight in JH throughout the experiment period.At the age of 398 d, determination coefficient of body length to body weight was higher than that of body height to body weight which revealed that body length was the dominant trait for both male and female individuals in all crosses. At the age of 598 d, the dominant traits were respectively body height for HJ（♀） and JL（♀） and body length for JL（♂）, HJ（♂）and JH（♀）. In the case of JH（♂）, the determination coefficients of body length, body height to body weight were almost the same. The determination coefficient of body length and body height to body weight was the important factor to the difference of heterosis among offspring.3. Genetic variation analysis on the genome DNA40 random primers were used to conduct random amplified polymorphic DNA （RAPD） analyse for the genome DNA of Jian carp, Huanghe carp and their F₁ hybrids. The results showed that 155 bands were produced with 33 selected primers, 105 bands of which were polymorphic. Different amplification bands were produced by primer S18, S472, S478（1600bp, 300bp and 950bp in size, respectively） in Jian carp and Huanghe carp, which could be used as molecular genetic markers to differentiate Jian carp from Huanghe carp.For Jian carp, Huanghe carp, direct cross F₁（JH） and reciprocal cross F₁（HJ）, the proportions of polymorphic loci were respectively 37.33%, 42.38%, 47.33% and 33.33% and genetic similarity indices were respectively 0.8240, 0.7921, 0.7920 and 0.8569. The order of gene diversity index and Shannon index were JH＞Huanghe carp＞Jian carp＞HJ. Huanghe carp and JH maintained higher degree of intrapopulation genetic variation, while HJ had the smallest degree of genetic variation. The inter-specific genetic distances was respectively 0.2233（JH to Jian carp）, 0.2436（JH to Huanghe carp）; 0.1749（HJ to Jian carp）, 0.2026（HJ to Huanghe carp）. The data revealed that F₁ hybrid inherited more genetic material from Jian carp than from Huanghe carp.Four variation types were shown by the RAPD maps. If these variations on genome DNA were associated with some economical traits, the differences on DNA sequences were the basis for heterosis production and its intensity vairation. In this experiment, heterosis was correlated with growth stage. Possible reasons that influenced heterosis were analyzed and some theoretical guidance to aquaculture were provided.更多还原