A Tufted A Genome Separation, Identification And Application Of Specific Repetitive Sequences

Belonging to Triticinae of Triticeae, Dasypyrum contains a large number of useful target genes for resistance to extensive powdery mildew and stripe rusts. It has strong ability of tiller, more spicules, bears drought, cold, slat and has high quantity of protein. All of these novel characteristics are useful for quality and yield improvement in modern wheat breeding program. Dasypyrum includes two species, D. villosum (L.) Candargy and D. breviaristatum (Lindb. F.) Frederiksen. D. villosum (L.) Candargy. At present, researches on Dasypyrum are almost concentrated on D. villosum, but rare on D. breviaristatum. By far, several set of T. aestivum -D. villosa addition, substitution and translocation lines have been created. Particularly, a wheat powdery mildew resistance gene, Pm21, from chromosome 6V, and wheat eye spot resistance gene, PchDv, from chromosome 4V, have been introgressed in common wheat, respectively. Moreover, a Triticum- Dasypyrum breviaristatum amphiploid is firstly created by Prof. Jiang Huaren of Sichuan Agriclutrure University of China. Based on the novel amphiploid, we set up a project to introduce excellent genes from Dasypyrum breviaristatum to common wheat. In this study, a set of secondary materials containing Dasypyrum breviaristatum chromatin was selected, which richened wheat breeding utilizing alien genes from triticeae.The detection of foreign chromatin becomes rather important with the increase of the dereivatives from wide crosses in wheat breeding. PCR-based Molecular marker techniques, such as RAPDs and SCARs, exhibiting excellent characteristics of less time-consuming, more reliable, was widely used by researchers. In this study, RAPD and SCAR techniques are used to produce Dasypyrum specific molecular marker. In addition, the chromosomal distribution was determined by fluorescences in situ hybridization (FISH). The results are shown as follows:1. Using RAPD approach, we obtained a high repetitive DNA sequence OPM2937 , which was assigned as a genbank number of AY375391.1, after screening 100 10-oligo primers. Based on the sequence, we developed a pair of primer, and successfully carried out in tracing the Dasypyrum chromatin by PCR analyses. A target bands about 937bp were observed both in Dasypyrum species and wheat-Dasypyrum breviaristatum derivatives. It is therefore that OPM2937 could be used as molecular marker to detect Dasypyrum chromatin introgressed into wheat background.2. Fluorescence in situ Hybridization (FISH) was carried out on Triticum- Dasypyrum breviaristatum partial amphiploid by using the probe of OPM2937. The result indicated that OPM2937 was specifically hybridized throughout all D. breviaristatum chromosomes arms except for the terminal and centromeric regions, which indicated that OPM2937 is a Dasypyrum specific repetitive sequence.