论文部分内容阅读
不同家蚕品种对家蚕核型多角体病毒(BmNPV)的抵抗性存在较大差异,家蚕抗性品系AN、野BN对BmNPV侵染具有较强的抵抗性.用易感家蚕品系C108分别与AN和野BN杂交、回交,构建两个抗性品系的BC3M和BC4M分离群体,利用简化基因组测序技术2b-RAD(基于IIB型限制性内切酶的RAD)进行亲本和杂交分离群体的基因组测序,通过生物信息学方法筛选位于染色体上与抗性相关的多态性SNP标记,进行抗性品种的基因型分析.对3个亲本及2个抗性分离群体样本基因组DNA构建的2b-RAD标签文库进行Illumina测序,获得抗性亲本AN、野BN的多态性SNP标记11 919个和12 293个.对抗性分离群体全基因组染色体的BmNPV抗性关联SNP标记指数(SNP-index)进行分析,结果表明亲本品系AN、野BN的BmNPV抗性相关SNP标记分布在多个染色体上,其中AN的全基因组中抗性贡献率前5位是第5、10、27、23和4号染色体,野BN的全基因组中抗性贡献率前5位的是第4、27、15、18和6号染色体,有多个SNP-index高值位点与已知BmNPV抗性相关基因的位置具有较高的一致性.推测AN、野BN两个品系的BmNPV高抗性与抗性主基因和其他抗性基因的联合作用有关.“,”The resistance of different silkworm (Bombyx mori) varieties to Bombyx mori nucleopolyhedrovirus (BmNPV) is quite different.Silkworm strains AN and Ye-BN have high resistance against BmNPV.A susceptible silkworm strain named C108 was used to hybridize and back-cross with AN and Ye-BN respectively for construction of two segregation populations (named BC3 M and BC4M) of the two resistant strains.Simplified genome sequencing technology 2b-RAD (RAD based on type liB restriction endonuclease) was employed to sequence genomes of the above parental strains and hybrid segregation populations.Bioinformatic methods were employed to screen resistance-related polymorphic SNP markers on chromosomes for analyzing genotypes of the resistant strains.Illumina sequencing was conducted to sequence the 2b-RAD tag libraries constructed from genomic DNA samples of 3 parental strains and 2 resistant segregation populations.As a result,11 919 and 12 293 polymorphic SNP markers were obtained from parental strains AN and Ye-BN respectively.Moreover,SNP-indexes related to BmNPV resistance were analyzed on whole-genome scale for the resistant segregation populations.It was found that SNP markers related to BmNPV resistance were distributed on multiple chromosomes in parental strains AN and Ye-BN.The top 5 chromosomes contributing to BmNPV resistance in strain AN were chromosomes 5,10,27,23 and 4.And those in strain Ye-BN were chromosomes 4,27,15,18 and 6.On these chromosomes,many loci with high SNP index values are consistent with loci of known genes related to BmNPV resistance.Therefore,it is suggested that the high BmNPV resistance of AN and Ye-BN strains is related to combined functions of major resistant gene(s) and other resistant genes.