CLASSIFICATION OF CULTIVATED RICES INTO INDICA AND JAPONICA TYPES BY THE ISOZYME, RFLP AND 2 MILLED-RICE METHODS

Four methods for classifying cultivated rices (Oryza sativa L.) (inclu ding IR varieties) into indica and japonica types - waxy gene product in endosperm starch, glutelin alpha(3) molecular weight in milled rice , RFLP polymorphism at the Wx locus and Glaszmann's isozyme method - w ere compared. On the basis of the two endo sperm traits and the RFLP m ethod Glaszmann's group 1 (indica) was classified as mainly indica and intermediate groups 2, 3 and 4 as exclusively indica. However, the en dosperm traits classified Glaszmann's group 5 as mainly indica, while the RFLP method classified it as japonica. The RFLP waxy gene probe wa s closest to the isozyme method in classifying group 6 as japonicas; t he waxy gene product gave mainly indica reaction even in group 6, and the glutelin alpha(3) method was intermediate. All IR rices were class ified as being indica on the basis of Wx gene product and by Glaszmann 's method, but a few were classified as japonica by the glutelin alpha (3) method and by the RFLP waxy gene probe.