AN RFLP SPECIES-SPECIFIC DNA-SEQUENCE FOR THE A-GENOME OF RICE

A DNA sequence, pOs6.20, was cloned from the nuclear genome of cultiva ted rice (Oryza sativa L.) by hybridization with a human minisatellite sequence. At high hybridization stringency, a subfragment of the rice sequence, pOs6.20.3, detected low-copy restriction fragment length po lymorphisms (RFLPs), which behaved as Mendelian genetic markers. This subfragment detected multicopy RFLPs between an indica and a javanica cultivar at medium hybridization stringency. The sequences detected by pOs6.20.3 at high hybridization stringency did not occur in rice spec ies possessing the B, C, D, E, and F genomes. These results suggest th at the RFLPs detected by this sequence can be placed on a genetic map of rice and that this sequence can be used as a species-specific probe for the A genome of rice.