簇毛麦2V染色体特异分子标记开发

Development of Specific Molecular Markers of 2V Chromosome in Haynaldia Villosa

簇毛麦是小麦遗传改良的重要基因资源之一,其2V染色体上携有抗白粉病、护颖颖脊刚毛、光周期响应、长穗多粒等许多普通小麦所不具备的优良基因,但缺乏足够的分子标记,不能准确鉴定导入小麦的2V染色质。为了开发2V染色体上特异分子标记,本研究设计了2套引物,一套是基于普通小麦第2群染色体不同区段表达序列标签设计的序列标记位点引物30对,另一套是基于小麦2D、黑麦2R测序结果同源比对的差异设计的内含子定位引物296对,分别筛选出2个和33个2V染色体特异分子标记,占总引物数6.7%和11.1%,说明基于新一代高通量测序技术设计内含子定位引物是一种开发染色体特异性标记的高效方法。研究结果进一步发现,大多数位于小麦2D染色体上的基因可以分别对应2V染色体相同区段上的基因,但也有例外,说明簇毛麦2V染色体与普通小麦2D染色体之间存在复杂的共线性关系。本研究共开发出35个标记,并对其可靠性进行了验证,其中lfz8187_(-1100)定位于2VS FL0.68-1.00,lfz8387_(-280)、lfz8462_(-760)和lfz8470_(-200)定位于2VS FL0.00-0.26,其余31个标记定位于2VL。这些分子标记为鉴定2V染色体结构变异提供了有效工具,也为鉴定导入普通小麦的2V染色体携带的有益基因提供了技术支撑。

Haynaldia villosa is an important genetic resource for wheat genetic improvement.The 2V chromosome in H.villosa,which hosts many important genes,such as powdery mildew resistance,glume ridge bristles,photoperiod response,longer spikes and more grains,are valuable in common wheat improvement.However,the lack of molecular markers to the 2V chromatin impairs the introgression into wheat.In order to develop specific molecular markers on chromosome 2V,we designed two sets of primers,including:(1)30 pairs of sequence-tagged site primers based on the expressed sequence tag sequences of different segments of the 2nd chromosome of common wheat,and(2)296 pairs of intron targeting primers designed based on the homologous comparison between wheat 2D and rye 2R.Two and 33 specific molecular markers on chromosome 2V were validated and successfully developed,accounted for 6.7%and 11.1%of the total primers tested,respectively.This result suggests that marker development based on next generation sequencing technology is an efficient method.Most of the genes on the 2D chromosome of wheat were collinear to those of the 2V chromosome,while few exceptions were also observed,indicating a complex collinearity on the 2V chromosome of H.villosa to the 2D chromosome of common wheat.A total of 35 markers were finally qualified,including lfz8187_(-100)that was located at 2VS FL0.68-1.00,and 1fz8387_(-280),Ifz8462_(-760)and Ifz8470_(-200)that were located at 2VS FL0.00-0.26,as well as 31 markers that were located on the long arm of 2V chromosome.Collectively,these markers provided an effective tool for identifying structural variation of H.villosa 2V chromosome,as well as the beneficial genes introgressed into common wheat.