翘嘴红鲌（♀）×团头鲂（♂）杂种F1的SRAP标记分析

Analysis on genetic variations of Erythroculter ilishaeformis （♀）×Megalobrama amblycephala （♂） Hybrids F1 by SRAP markers

摘要:

相关序列扩增多态性(sequencerelated amplified polymorphism，SRAP)是基于PCR技术的一种新型分子标记技术。运用SRAP分子标记技术对翘嘴红鲌（♀）×团头鲂（♂）杂种F₁及其父母本的遗传变异进行了分析。从24个SRAP引物组合中筛选到21个多态性引物组合，共得到136条清晰稳定的扩增位点，其中124个扩增位点具有多态性，平均每个引物组合产生6.48个多态性条带，显示了较高的多态性比率。杂种F1的SRAP扩增条带均能在亲本中找到，未发现杂种F1特异性条带，直观显示杂种F₁确为杂交种。翘嘴红鲌、团头鲂及其杂种F₁的Nei’s多样性指数（H）分别为0.194 5、0.172 2、0.198 4，Shannon’s信息指数（I）分别为0.289 1、0.254 7、0.290 5，表明杂种F1比其父母本有更高的遗传多样性水平。翘嘴红鲌与团头鲂间的遗传距离为0.420 6，两者基因组有较大的相似性。杂种F₁与翘嘴红鲌和团头鲂间的遗传相似性分别为0.767 1、0.751 2，两者相差甚微，显示杂种F₁与双亲的相似程度没有明显的倾向性，表明属间杂种F₁整合了翘嘴红鲌和团头鲂的遗传信息。研究结果也表明SRAP分子标记技术是比较稳定可靠的标记系统，可有效用于鱼类杂种真实性的鉴定和遗传变异分析。

Abstract:

SRAP (sequencerelated amplified polymorphism) is a new molecular marker based on Polymerase Chain Reaction. SRAP markers were used to detect genetic variations of two parents E.ilishaeformis ♀, M.amblycephala ♂ and the F₁ in this paper. 21 polymorphic primer combinations were selected from 24 pairs of primer combinations. 136 loci were amplified and 124 loci were polymorphic. Each primer combination generated 6.48 polymorphic loci, which showed comparatively high polymorphism on average. The results showed that the differentiations between parents were remarkable, and all the loci of F₁ came from their parents, and no hybridspecific locus was found. Among E.ilishaeformis ♀, M.amblycephala ♂ and F₁, the values of Nei’s genetic diversity (H) were 0.194 5, 0.172 2, 0.198 4, respectively; the values of Shannon’s information index (I) were 0.289 1, 0.254 7, 0.290 5 respectively. All the parameters indicated that hybrids F₁ showed a greater genetic diversity than their parents. Furthermore, the genetic distance between E.ilishaeformis ♀ and M.amblycephala ♂ was 0.420 6. The genetic identity between F₁ and E.ilishaeformis ♀ was 0.767 1, and the genetic identity between F₁ and M.amblycephala ♂ was 0.751 2, the differentiation was insignificant. This indicated that the hybrid F₁ has an equal heredity similarity to their parents, and this also showed that F₁ combined genetic information from both of their parents. The results also demonstrated that SRAP molecular marker technology can be applied to the hybrids tested and genetic analysis of fish breeding effectively and reliably.