哲罗鲑(♂)与细鳞鲑(♀)属间杂交不相容现象的SSR分析

Genetics analysis on incompatibility of intergeneric hybridizations between Hucho taimen(♂) and Brachymystax lenok(♀) by using 30 polymorphic SSR markers

利用哲罗鲑(Hucho taimen,♂)与细鳞鲑(Brachymystaxc lenok,♀)进行属间杂交,出现了仔鱼上浮率低和畸形率高等杂交不相容现象,为探究哲罗鲑与细鳞鲑属间杂交不相容现象产生的原因,本研究采用30对微卫星引物对杂交亲本及F1进行遗传分析。结果表明:(1)30对微卫星引物中,2对在细鳞鲑中未出现扩增带,3对在哲罗鲑中未出现扩增带,其余25对在双亲中均扩增出差异条带;(2)在双亲中具有差异的25个微卫星位点中,除Omi84TUF位点在1个F1出现非亲条带外,其余位点所有条带均来自于双亲,其中21个位点完全符合孟德尔遗传规律,表明哲罗鲑与细鳞鲑属间杂交属两性融合生殖,大部分遗传物质来源于父母本双方;(3)4个位点Omi105TUF、Omi156TUF、Omi165TUF及Omy16DIAS在部分子代中出现2条母本条带或父本条带缺失现象,可能是部分亲本染色体在配对或分离过程中产生了异常,出现染色体丢失或异源加倍现象,非整倍体的较早出现可能是导致杂交不相容的直接原因;4)F1与哲罗鲑和细鳞鲑的遗传相似系数分别为0.673 5和0.729 8,遗传距离分别为0.395 3和0.315 0,表明F1与细鳞鲑亲缘关系更近,UPGMA聚类分析也支持这一观点。

Intergeneric hybridizations ofHucho taimen（♂） and Brachymystax lenok（♀） were produced in this study The results showed phenomenon of hybrid incompatibility such as low larval floating rate and high deformity rate. Thirty microsatellite primers were used for genetic analysis on relationship between F1 hybrids and their parents. The results are as follows： 1） Among the 30 microsatellite primers, twenty-five pairs showed specific bands on both parents, and two pairs showed specific bands only on H. taimen, while three pairs only on B. lenok. 2） Among the 25 microsatellite primers showing specific bands on both parents, 24 bands of microsatellite locus came from parents and only one locus Omi84TUF appeared in F1 hybrids. The inherited character of 21 locus completely follows the Mendelian rule indicating that the hybridization between the parents are gamogenesis and most genetic material come from both of the parents. 3） Four loci OmilO5TUF, Omil56TUF, Omil65TUF and Omyl6DIAS showed doubled maternal bands or no paternal specific bands on some F1 hybrids. This may be caused by abnormality in process of pairing or separation for some chromosomes, which may result in hybrid incompatibility. 4） The genetic similarity and genetic distance between F1 hybrids and H. taimen were 0.673 5 and 0.395 3 respectively, and the genetic similarity and genetic distance between F1 hybrids and B. lenok was 0.729 8 and 0.315 0 respectively. The results showed F1 hybrids had closer relationship with B. lenok. It was also supported by UPGMA clustering.