为了解作图群体亲本间基因组和密集QTL区的遗传变异,促进QTL定位与克隆,本研究对一个甘蓝型油菜(Brassica napus)重组自交系(recombinant lnbred lines,RIL)群体双亲M083和888-5(二者株高、分枝数、开花时间、菌核病抗性等性状差异显著)的基因组进行深度测序和分析。研究结果表明:在M083和888-5中分别检测到SNP个数为1 941 397和2 046 009,In Del个数为410 961和428 572,结构变异个数为90 384和88 456,拷贝数变异个数为46 655和46 008。对包含开花时间、菌核病抗性、株高等多个性状主效QTL密集的A02染色体进行分析发现,在包括上述性状QTL密集的6.4~6.9Mb的0~8.5Mb基因组区间内,两品系SNPs和In Dels变异数量/密度总体呈相反的趋势;片段丢失也有热点区,888-5和M083均在两个共同区域高频发生,其中一个为QTL密集区;倒位在染色体上的分布虽然也是不均匀的,但两品种间发生区域不同,且与QTL无关。本文关于基因组变异(SNPs、In Dels、除倒位外的结构变异)热点区和QTL密集区重复的结论对性状控制位点精细定位、基因克隆及育种亲本选择有一定的指导意义。
To facilitate fine mapping and gene cloning,variations of whole genome and dense QTL regions of Brassica napus were investigated by sequencing 2 parents(M083 and 888-5,with significant differences in plant height,branch numbers,flowering time and resistance to Sclerotinia disease) and their RIL(recombinant inbred line) population. Results showed that M083 and 888-5 genomes had large amount of variants,including1 941 397 and 2 046 009 SNPs,410 961 and 428 572 In Dels,90 384 and 88 456 SVs,46 655 and 46 008 CNVs respectively. Chromosome A02 was analyzed in detail for its dense QTLs on flowering time,Sclerotinia resistance and plant height. At a QTL dense region(6. 4-6. 9Mb) of 0-8. 5Mb genome,the 2 parents had converse trends in distribution of SNPs and In Dels. Segmental loss had hotspot regions in the same 2 regions of the parents with high frequency,and one of them contained the dense QTL region. Inversion distributed unevenly with hotspots in different regions in the parents. It had no overlap with QTL region. The possible causal relationship between hotspots of genomic variation(SNPs,In Dels and SVs except for inversion) and dense QTL region might refine QTL mapping and cloning.