白鲫×团头鲂杂交后代遗传及繁殖特性研究

远缘杂交是一种重要的鱼类遗传育种手段。申请者利用日本白鲫与团头鲂进行远缘杂交，在其后代中形成了两性可育的异源四倍体鲫鲂、天然雄核发育团头鲂，以及不育的异源三倍体鲫鲂；异源四倍体鲫鲂进行自交，获得了两性可育的同源四倍体鲫和二倍体鲫品系。在此基础上，本项目拟采用FISH、GISH、全长转录组、性腺切片等技术，对这些远缘杂交后代及形成的可育品系的染色体组成、直系同源基因的遗传变异、性腺发育和配子形成等分子生物学及繁殖生物学特性进行系统研究，以揭示他们的遗传与繁殖规律。此外，本项目还将利用新型的同源四倍体鱼以及二倍体鲫与其他鱼类杂交，来制备新型的三倍体鱼和二倍体鱼。本项目在鱼类育种方面具有重要意义。

Distant hybridization is an important breeding method in fish. In our previous study, we obtained androgenetic blunt snout bream (2n=48), allotriploid hybrids (3n=124) and allotetraploid hybrids (4n=148) from the hybridization of two species from different subfamilies: Carassius auratus cuvieri (♀, 2n = 100) and Megalobrama amblycephala (♂, 2n = 48). Besides, diploid crucian carp (2n=100) and autotetraploid (4n=200) were produced by self-mating of allotetraploid. In this program, we plan to study the genetics and reproductive characteristics of those different ploidy levels hybrids, including the chromosome composition, genetic variation, gonad development and gamete formation of the hybrids by using GISH, FISH, full-length transcriptome and gonad tissue slice. In addition, we will also use the diploid crucian carp and autotetraploid to mate with other diploid fish to produce new kinds of hybrid fish. Completion of this program will provide important theoretical knowledge for the genetic and reproductive law of the fish distant hybridization and is important in fish genetic breeding.