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期 刊 ：植物遗传资源学报 2015年 16卷 4期

关键词：赖草；Cot-1 DNA；荧光原位杂交；重复序列；染色体标记；

Keywords:L. secalinus, Cot-1 DNA, FISH (fluorescence in situ hybridization), repeat sequence, chromosome marker,

摘 要 ：本研究通过构建Cot-1 DNA文库以及荧光原位杂交技术筛选，从赖草(Leymus secalinus (Georgi) Tzvel)克隆得到一个在染色体多个部位具有点状杂交信号的重复序列。进一步对该序列在赖草基因组进行克隆和分析表明该序列为一个具有90 bp的重复单元(pLs-90)，并在基因组中呈串联状排列。利用pLs-90对赖草进行分子核型分析，结果表明：pLs-90在染色体的着丝粒、近着丝粒、臂间、以及近端粒区均有分布，而且在每对染色体上信号分布模式不尽相同，结合染色体臂比可以清楚地对赖草的 14 对(28条)染色体进行识别。pLs-90不仅可作为赖草种质鉴定和利用中染色体识别的理想标记，也可作为研究小麦族不同物种染色体组进化的有力工具。

Abstract:A repeat sequence producing the multiple hybridization signals on chromosomes was obtained by constructing a Cot-1 DNA library and screening with a technique of fluorescence in situ hybridization (FISH) in Leymus secalinus (Georgi) Tzvel. Further cloning and sequence analysis revealed that the sequence is tandem repeated in the genome with a repeated motif of 90 bp. The repetitive sequence was named as pLs-90. Karyotyping with pLs-90 revealed that each chromosome of L. secalinus could be well identified by the different FISH patterns with multiple hybridizations on centromeric, subcentromeric, interstitial, or subtelomeric ?regions. PLs-90 can not only be an idea chromosome maker for Leymus germplasm identification and utilization but also a powerful tool for studying the genome evolution of different species in Triticeae.

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