远缘杂交是一种重要的鱼类遗传育种方法，如果远缘杂交能形成可育的异源品系，则为遗传育种提供了重要的种质资源库。申请者所在实验室发现，团头鲂和翘嘴红鲌属间远缘杂交F1代中的二倍体雌雄两性可育，利用二倍体鲂鲌自交，已经成功获得了二倍体鲂鲌杂交品系（F1-F3）。鲂鲌杂交品系的形成为研究二倍体鱼杂交品系的形成机制提供了良好的模型。在此基础上，本项目将利用GISH和FISH等技术，对二倍体鲂鲌杂交品系的染色体组成、遗传变异及性腺发育和配子形成等遗传和繁殖方面的主要生物学特性进行研究,探索鲂鲌杂交品系的形成机制。另一方面，还将用该品系与翘嘴红鲌等二倍体鱼交配制备新型杂交鱼。本项目可为二倍体鱼品系遗传育种提供重要理论知识，在鱼类遗传育种和鱼类演化方面都具有重要意义。

Distant hybridization is an important breeding method in fish. If distant hybridization generated fertile heterogenous hybrid, it would provide excellent germplasm banks for genetic breeding. In the F1 hybrids of female Megalobrama Amblycephala × male Culter Alburnus, the diploid hybrids are detected to be bisexual fertile. A diploid hybrid lineage (F1-F3) has been successful established by self-crossing of the diploid hybrids. The formation of the hybrid lineage of Megalobrama Amblycephala × male Culter Alburnus provides good experiment model to study the formation mechanism of diploid hybrid linage. In this program, we plan to study the genetics and reproductive characteristics of diploid hybrid lineage, including the chromosome composition, genetic variation, gonad development and gamete formation of the hybrid linage by GISH and FISH to explore formation mechanism of diploid hybrid lineage. In addition, we will also use the hybrid lineage to mate with other diploid fish to produce new kinds of hybrid fish. Completion of this program will provide important theoretical knowledge for genetics breeding in diploid hybrid lineage fish and is important both in fish genetic breeding and evolution.