利用SLAF-Seq结合BSA方法分子标记‘小白冬麦’抗白粉病基因mlxbd

Molecular Mapping of Powdery Mildew Resistance Gene mlxbd by SLAF-Seq and BSA Method

白粉病严重威胁着小麦的产量和品质,地方品种‘小白冬麦’对白粉病具有良好的抗性。为进一步精细定位‘小白冬麦’抗白粉病基因,利用SLAF测序,结合BSA方法将抗病基因mlxbd定位在小麦7BL染色体上总长度19.26Mb的候选区域内[参照小麦CSS(Chromosome survey sequence)基因组(IWGSC,2014)]。将候选区域对应到‘中国春’IWGSC RefSeqv1.0基因组(IWGSC,2018)7BL染色体上,位置为611088744~723157603。在抗感材料间,定位于染色体候选区间内的SNP和InDel分别有788个和47个。利用已经报道的与mlxbd和mlmz基因连锁标记,进一步将候选区域缩小,基因mlxbd进一步定位于染色体700631952~711234115。基因功能参照IWGSC RefSeqv1.0(IWGSC,2018)注释,筛选出9个含有NBS或者LRR抗病结构域的基因。利用已有小麦转录组数据库对候选基因分析发现,候选区域内有5个基因受小麦白粉病菌诱导。

Powdery mildew is a serious threat to the yield and quality of wheat.The landraces‘Xiaobaidongmai’winter wheat has good resistance to powdery mildew.In order to find mapping powdery mildew resistance gene mlxbd,the mlxbd gene was located on the 3 candidate regions of the chromosome 7BL with a total length of 19.26 Mb[Reference wheat CSS(Chromosome Survey Sequence)genome(IWGSC,2014)]by SLAF sequencing and combiningwith BSA method in this study.The candidate regions were corresponded to the Chinese Spring IWGSC RefSeq v1.0 Genome(IWGSC,2018)on chromosome 7BL(611 088 744-723 157 603)with 788 SNPs and 47 InDels between resistance and susceptible plants.We used the reported linkage markers of the mlxbd and mlmz genes to further narrow the candidate region,and the mlxbd gene is mapped between chromosome 700 631 952 and 711 234 115.According to IWGSC RefSeq v1.0 annotation(IWGSC,2018)of gene function,the nine genes were screened out,which contained NBS or LRR disease resistance domains.An online published transcriptome database indicated that 5 genes were responsible for resistance to Bgt E09 in wheat.