中文摘要：

根据簇毛麦长末端重复序列Sabrina设计引物,进行PCR筛选,获得了偃麦草属（Thinopyrum）物种的特异分子标记OPV1079,比对结果显示标记OPV1079与簇毛麦（Dasypyrum）基因组高度重复序列有95%的同源性,说明簇毛麦属与偃麦草属物种在重复序列的组成和分布上有较大的相似性。为了深入探讨该两属染色体组的关系,以二倍体簇毛麦（V染色体组）总DNA为探针,对八倍体小偃麦进行原位杂交,发现有5条染色体在除端部和着丝粒处外具有强烈的弥散状杂交信号;以四倍体簇毛麦（VbVb染色体组）总DNA为探针,对中间偃麦草（JJSSt染色体组）进行杂交,发现有14条染色体在端部有杂交信号。结果表明染色体组V形成Vb过程中发生了较大重组,并且V较Vb与St有更近的遗传关系,说明基因组重复序列在小麦族物种的遗传分化中发挥了巨大作用,同时对物种遗传关系研究也为外源物种优异基因向小麦中转移提供了理论指导。

英文摘要：

A pair of specific primers, H12VF and H12VR, was designed based on LTR repetitive sequence （GenBank No. DQ167398） from Dasyprum. breviaristatum. By using this pair of primers, and with comparison of ordinary wheat, PCR amplification was performed on materials containing chromatin of Thinopyrum intermedium. The results indicated that there was a specific DNA band of 1079bp（named OPV1079） in materials containing chromatin of Th. intermedium, but there was no amplification in any wheat tested. Further research suggested that the 1079bp-DNA band could be used as a molecular marker for detection of wheat——Th. intermedium partial amphiploids and their derived offspring. Sequence similarity analysis indicated that OPV1079 was 95% homology to DQ167398. So, further study was needed in discussing the genomic relationship between the two genera of Dasypyrum and Thinopyrum. Using the probe of total genomic DNA of D. villosum, Octoploid trititrigia 78784 was analyzed by Genomic in situ hybridization （GISH）. We observed that the hybridization signals were throughout five chromosomes arms except for the terminal and centromeric regions. Moreover, Th. intermedium was analyzed by in situ hybridization with the probe of total genomic DNA of D. breviaristatum, and the result showed that only terminals of fourteen chromosomes had hybridization signals. All the results suggested that there was close relations between genome V and genome St. The approaches for exploring genome relationships among species in triticeae using GISH combining with PCR analysis of repetitive sequence, will shed light on genomic origin and evolution, and enhance the chromosomal manipulation for wheat breeding.