Development of simple sequence repeat markers in rye (Secale cereale L.).
Development of simple sequence repeat markers in rye (Secale cereale L.).
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DOI：
10.1139/g99-052
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发表时间：
1999-10
期刊：
影响因子：
3.1
通讯作者：
B. Saal;G. Wricke
中科院分区：
文献类型：
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作者：
B. Saal;G. Wricke
简单重复序列（SSR），也称为微卫星，代表了近年来在哺乳动物和植物基因组中描述的基于PCR的标记系统。在自花授粉作物植物中，就多态性水平而言，它们已显示出优于其他DNA标记的上级。与RFLP标记相比的技术优势也将有助于黑麦等异交作物的标记分析。为了确定SSR标记在黑麦遗传育种中的应用价值，对黑麦基因组文库进行了（CT/GA）n和（GT/CA）n二核苷酸重复序列的筛选。据估计，这些基序以每268-519 kb一个的频率出现。对182个阳性克隆中的74个进行了测序，大多数（56.8%）显示完全重复，主要是（GT/CA）n型（61.9%）。共设计了57对引物，其中27对（47.4%）产生了特异性SSR标记，其中20对已被定位或分别定位到染色体或染色体臂上。利用4个SSR标记和3个RFLP标记对2个自由授粉黑麦品种进行了多态性分析。平均而言，SSR标记在两个品种中表现出更大的期望杂合度（0.62比0.43）和等位基因数（5.9比3.4）比RFLP标记的值。
Simple sequence repeats (SSRs), also referred to as microsatellites, represent a PCR-based marker system that has been described in mammalian and plant genomes in recent years. In self-pollinating crop plants they have been shown to be superior to other DNA markers with respect to their level of polymorphism. The technical advantages compared with RFLP markers should also facilitate marker analysis in outcrossing crops like rye. In order to determine the usefulness of SSR markers in rye genetics and breeding, several genomic libraries were screened for (CT/GA)n and (GT/CA)n dinucleotide repeats. It was estimated that these motifs occur at a frequency of one per 268-519 kb. Seventy four out of 182 positive clones were sequenced, and the majority (56.8%) revealed perfect repeats, predominantly of the type (GT/CA)n (61.9%). Fifty seven primer pairs were designed and 27 (47.4%) resulted in specific SSR markers, of which 20 were genetically mapped or assigned to chromosomes or chromosome arms, respectively. The level of polymorphism of four SSR and three RFLP markers was assessed in two open-pollinated rye cultivars. On average, the SSR markers showed larger values of expected heterozygosity (0.62 vs. 0.43) and allele number (5.9 vs. 3.4) than RFLP markers in both cultivars.