水稻(Oryza sativa L.)核基因组存在叶绿体psbA基因的同源片段

序列比较说明，重复DNA顺序pRRD9与水稻叶绿体基因组中编码QB蛋白的psbA基因存在高度的同源。用pRRD9亚克隆片段pRRD9R和片段pRRD9L对水稻的叶绿体和核DNA进行Southern杂交分析，揭示了psbA基因同源片段在某个进化时期由叶绿体基因组转移到水稻核基因组，而且两者在水稻进化过程中的变异程度存在明显的差异。利用它们对野生稻和栽培稻总DNA的Southern杂交分析，显示亚洲栽培稻与AA基因组型的野生稻有较近的亲缘关系，以及在部分野生稻产生特异的杂交带谱，说明它可以作为一种分子探针来研究水稻的进化问题。

NUCLEAR GENOMIC HOMOLOGOUS SEQUENCE OF CHLOROPLAST psbA GENE IN RICE (ORYZA SATIVA L.)

Sequence comparison showed the high homology between rice repetitive DNAsequence pRRD9 and chloroplast gene psbA encoding QB protein. Southern hybridizationsof rice chloroplast and nuclear DNA with the two subcloned segments from pRRD9,pRRD9R and pRRD9L, revealed that psbA gene sequence was transferred from chloroplastto the nuclear genome in rice at a certain evolution stage. Significant differences occurredbetween the two segments in the ev0lution of rice variation. Southern analysis of wild andcultivated rices with the segments showed that the cultivated Asian rice had closer relativeof the wild rice with AA genome type. In addition, specific hybridization patterns werealso detected in some wild rices. These findings suggest that pRRD9 may be a goodmolecular probe for the study of the evolution of rice.