Abstract: Genomic in situ hybridization(GISH) is a powerful tool to characterize parental chromosomes in interspecific hybrids,including the behaviour of autosynapsis and chromosome pairing,which could be used to distinguish the chromosomes of O.sativa from wild species in a spontaneous interspecific hybrid.The chromosome pairing in meiotic metaphase Ⅰ of the hybrid between O.sativa and O.minuta was investigated by GISH.The hybrid was a triploid with 36 chromosomes according to the chromosome number investigated in mitosis of root tips.In meiotic metaphaseⅠof the hybrid,less chromosome pairing was observed and most of the chromosomes existed as univalents.Based on GISH analysis,the chromosomes of the hybrid were composed of genomes A,B and C.So it was believed that the hybrid was the result of natural hybridization between cultivated rice Oryza sativa and wild species O.minuta which was planted in experimental fields.

Key words: wild rice, interspecific hybrid, genomic in situ hybridization, fluorescent in situ hybridization

摘要： 利用基因组荧光原位杂交（GISH）技术快速鉴定了栽培稻与野生稻的天然异交种的基因组组成，分析了该杂种在减数分裂中期Ⅰ的染色体配对情况。根据根尖细胞的染色体数目，发现该杂种是具有36条染色体的三倍体；通过减数分裂中期Ⅰ染色体的配对研究，发现该杂种染色体很少发生配对，绝大部分染色体以单价体形式存在；结合GISH技术的分析，证实该杂种是由A、B和C 3个染色体组组成。因此该杂种是栽培稻和小粒野生稻的天然杂交种。

关键词: 野生稻, 种间杂交种, 基因组荧光原位杂交, 荧光原位杂交