Abstract: Allozyme variation of cultivated rice (Oryza sativa L.) in China's Taiwan Province was investigated using 1 591 cultivars based on 14 allozyme loci Pgi1, Pgi2, Amp1, Amp2, Amp3, Amp4, Sdh1, Adh1, Cat1, Icd1, Est1, Est2, Est5 and Est9. The analysis showed that there existed 47 alleles in the tested materials, which covered 78.3% of total 60 alleles found in Oryza sativa L. in the world by the method of gel electrophoresis with system I. In the tested cultivars, the allele frequencies ranged from 0.001 to 0.997 and the gene diversity indexes (Ha) from 0.006 to 0.585. The average gene diversity index (Ht) and the degree of polymorphism (DP) were 0.239 and 18.3, respectively. Of 47 alleles observed, 24 ones (51%) had gene frequencies less than 0.05, and 5 ones (Amp1-1, Adh1-1, Icd1-1, Est1-1, Est5-1) higher than that of 0.95. It was found that there were 182 genotypes based on tested alleles, and allele Est9-null was only identified from 3 rice cultivars in Taiwan Province. The results of genetic differentiation index (Gst) and cluster analysis indicated that the difference of indica and japonica cultivars was significant in cultivars in Taiwan Province, especially in the loci of Amp2, Cat1, Pgi1, Est2 and Pgi2. The result reveals that cultivated rice in Taiwan Province is richer in genetic diversity in term of allozyme alleles, and is an important part of genetic diversity of Chinese rice germplasm.

Key words: Cultivated rice, Rice germplasm, Allozyme analysis, Genetic diversity, Taiwan Province, China