Han Haiming, Liu Weihua, Lu Yuqing, Zhang Jinpeng, Yang Xinming, Li Xiuquan, Hu Zanmin, Li Lihui
National Key Facility for Crop Gene Resources and Genetic Improvement (NKCRI), Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization (MOE) and Key Laboratory of Crop Genomics and Genetic Improvement (MOA), Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100193, China.
Planta. 2017 Feb;245(2):425-437. doi: 10.1007/s00425-016-2616-1. Epub 2016 Nov 10.
Different types of P genome sequences and markers were developed, which could be used to analyze the evolution of P genome in Triticeae and identify precisely wheat- A. cristatum introgression lines. P genome of Agropyron Gaertn. plays an important role in Triticeae and could provide many desirable genes conferring high yield, disease resistance, and stress tolerance for wheat genetic improvement. Therefore, it is significant to develop specific sequences and functional markers of P genome. In this study, 126 sequences were isolated from the degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR) products of microdissected chromosome 6PS. Forty-eight sequences were identified as P genome-specific sequences by dot-blot hybridization and DNA sequences analysis. Among these sequences, 22 displayed the characteristics of retrotransposons, nine and one displayed the characteristics of DNA transposons and tandem repetitive sequence, respectively. Fourteen of 48 sequences were determined to distribute on different regions of P genome chromosomes by fluorescence in situ hybridization, and the distributing regions were as following: all over P genome chromosomes, centromeres, pericentromeric regions, distal regions, and terminal regions. We compared the P genome sequences with other genome sequences of Triticeae and found that the similar sequences of the P genome sequences were widespread in Triticeae, but differentiation occurred to various extents. Additionally, thirty-four molecular markers were developed from the P genome sequences, which could be used for analyzing the evolutionary relationship among 16 genomes of 18 species in Triticeae and identifying P genome chromatin in wheat-A. cristatum introgression lines. These results will not only facilitate the study of structure and evolution of P genome chromosomes, but also provide a rapid detecting tool for effective utilization of desirable genes of P genome in wheat improvement.
人们开发了不同类型的P基因组序列和标记，可用于分析小麦族中P基因组的进化，并精确鉴定小麦-冰草渗入系。偃麦草属的P基因组在小麦族中发挥着重要作用，可为小麦遗传改良提供许多具有高产、抗病和抗逆性的优良基因。因此，开发P基因组的特异性序列和功能标记具有重要意义。在本研究中，从显微切割的6PS染色体的简并寡核苷酸引物聚合酶链反应（DOP-PCR）产物中分离出126个序列。通过斑点杂交和DNA序列分析，鉴定出48个序列为P基因组特异性序列。在这些序列中，22个具有反转录转座子的特征，9个和1个分别具有DNA转座子和串联重复序列的特征。通过荧光原位杂交确定了48个序列中的14个分布在P基因组染色体的不同区域，分布区域如下：遍布P基因组染色体、着丝粒、着丝粒周围区域、远端区域和末端区域。我们将P基因组序列与小麦族的其他基因组序列进行比较，发现P基因组序列的相似序列在小麦族中广泛存在，但存在不同程度的分化。此外，从P基因组序列中开发了34个分子标记，可用于分析小麦族18个物种的16个基因组之间的进化关系，并鉴定小麦-冰草渗入系中的P基因组染色质。这些结果不仅将促进对P基因组染色体结构和进化的研究，还将为有效利用P基因组优良基因改良小麦提供快速检测工具。
