Abstract: Total thirty throe parents of hybrid rice ( Oryza sativa L. ), including twenty five rice male sterile lines, throe maintainer lines and five restore lines, were analyzed by using twenty SSR (simple sequence repeats) primer pairs which disperse on 12 chromosomes in rice. Those primers detected 102 alleles among 33 parents of hybrid rice. PIC (polymorphic index content) values ranged from 0.274 to 0.773. PIC value is 0.554 on the average. Five SSR primer pairs selected from fifty six primer pairs can distinguish individually all of the rice male sterile lines and restore lines in the present study. As results from cluster analysis, it was concluded as follows. (1) Rice male sterile lines have abundant genetic diversity in China. Genetic background was vulnerable among rice male sterile lines used in large scale. (2) In indica rice, genetic variation of the restored lines is larger than that of the male sterile lines. (3) The restored lines were clustered separately from the male sterile lines which are grown widely for production.

Key words: Simple sequence repeats, Parents of hybrid rice, Genetic variation