Abstract: Specific and degenerated oligonucleotide primes were designed according to the sequences of known plant disease resistance genes and the conserved region of protein kinases. The products of polymerase chain reaction amplified from rice genomic DNA using these primes were cloned. Twenty-six of the clones were assigned to 34 loci on two rice molecular linkage maps. Chro- mosomal locations for 10 clones corresponded to 8 previous reported rice disease resistance genes. The property of some clones with chromosomal locations corresponded to the known blast resistance genes was further confirmed by restriction fragment length polymorphism analysis of the genomic DNA of blast resistance isogenic lines. Some of the clones as the probes differentiated the resistance isogenic lines from the susceptible recurrent parents.

Key words: Blast, Bacterial blight, Molecular marker, Rice