摘要
从籼稻（ＯｒｙｚａｓａｔｉｖａＬ．ｓｐｐ．ｉｎｄｉｃａ）“窄叶青”中克隆到了１个重复序列（ｐＯｓ１３９）。经分子杂交证明，ｐＯｓ１３９为一稻属内ＡＡ基因组特异的串联重复序列。序列分析表明，ｐＯｓ１３９以３５５ｂｐ为一重复单位。以ｐＯｓ１３９为探针对２９份中国普通野生稻和４３份中国栽培稻的基因组ＤＮＡ进行的分子杂交表明，籼、粳亚种之间具有明显的差异，籼稻杂交带数明显多于粳稻，普通野生稻与籼稻相似，具有较多的杂交带数。拷贝数测定结果表明，ｐＯｓ１３９在普通野生稻和籼稻中丰度均较高，在粳稻中丰度较低。结合ｐＯｓ１３９的Ｓｏｕｔｈｅｒｎ杂交结果和以前的ＲＡＰＤ结果，认为籼稻和粳稻共同起源于普通野生稻。
Repetitive DNA sequences are useful molecular markers for studying plant genome evolution and species diversity. The authors report the isolation and characterization of repetitive DNA sequences (pOs139) from Oryza sativa cultivars “Zhaiyeqing”. By Southern blot analysis, the authors discovered that pOs139 sequences were organized not only tandemly, but also highly specific for the AA genome of Oryza genus. Sequence analysis revealed that the clone pOs139 contains a 355 bp repetitive unit. The genomic DNA of 29 Chinese common wild accessions, and 43 cultivated rice accessions, were analyzed by Southern blot with pOs139 as a probe. The results illustrated that there was significant difference in hybridization patterns between japonica and indica subspecies. Hybridization bands of indica subspecies were much more than those of japonica, and the Chinese common wild rice was similar to indica in hybridization patterns. The copy number estimated by dot blot hybridization analysis indicated that a considerable degree of variation existed among different accessions of O.sativa and the Chinese common wild rice. It is interesting to note that japonica subspecies contains relatively low copy numbers of pOs139 related repetitive DNA sequences, while the indica and Chinese common wild rice contain relatively high copy numbers.
基金
国家自然科学基金
关键词
野生稻
栽培稻
串联重复序列
进化
Chinese common wild rice
Cultivated rice
Tandemly repeated DNA
Evolution
