Genotypic characterization of blast resistance genes in korean rice cultivars using molecular markers

Abstract Rice blast, caused by Magnaporthe oryzae , is one of the most serious threats to global rice production, highlighting the need for effective resistance breeding. This study demonstrates the utility of molecular markers in detecting key blast resistance genes in 259 Korean rice cultivars ( japonica group). Among the identified genes, Piz-t/Piz-5 and the Pita + Pita-2 combination emerged as the most significant contributors to blast resistance. Piz-t/Piz-5 showed the strongest and most stable resistance, especially in early-maturing cultivars, making it a valuable target for breeding programs focused on early-ripening rice. The Pita + Pita-2 combination provided broad-spectrum resistance across all maturity groups, functioning independently of the number of pyramided genes. These findings suggest that Piz-t/Piz-5 is effective as a single gene in early-maturing cultivars, while the Pita + Pita-2 combination can be strategically used in diverse japonica rice varieties. This study provides a practical framework for enhancing blast resistance through marker-assisted selection, aiding the development of more resilient and high-yielding Korean rice cultivars.