VARIATIONS IN PEROXIDASE ISOZYMES OF ORYZA PERENNIS AND O. SATIVA

抄録

Peroxidase isozymes in various vegetative organs of a wild rice species, Oryza perennis Moench, were investigated using the starch-gel electrophoresis method. From leaf blade, leaf sheath, internode, basal node, and root, eight isozyme bands were found running toward the anode and five bands running toward the cathode. Each organ showed a specific pattern of band distribution, and strains differed in the presence or absence of certain bands. In the leaf blade, leaf sheath and root, the activities of the bands were found to differ with the age of the organ.
In seven perennis populations of different origin, within-populational variations in zymograms were examined. Populations of perennial habit, one from India and three from Africa, each showed several different zymograms, but annual populations from India and from the Amazon basin were not polymorphic. Further, the zymograms of leaf blade and leaf sheath were observed in 111 perennis strains collected from the natural habitats in different countries (each represented by one plant), 38 sativa strains from various Asian countries, and the intermediate perennis-sativa strains from Jeypore Tract, India. The zymograms of perennis strains were quite variable, and the frequencies of certain bands markedly differed among geographical strain-groups. Most African and American strains had bands 4A and 5C, which were not frequent in the Asian material. Of several zymogram types of leaf blade found among Asian perennis strains, two, peculiar to the Asian strain-group, were found to characterize sativa varieties. Most Indica varieties had band 4C, which most Japonica varieties did not show. The semi-wild strains from Jeypore Tract showed a similar variation pattern as found in sativa varieties. Cultivated rice seemed to have arisen from wild forms having certain peroxidase isozymes.