Mining for major blast resistance genes in rice landraces of Karnataka

Rice blast caused by Magnaporthe oryzae is the most devastating disease. Host-plant resistance is one of the important approaches to tackle this disease. India being the center of origin of rice, shelters numerous landraces adopted to overcome biotic and abiotic stresses. Three well characterized blast resistance genes, Pi1, Pi2 (Piz-5) and Pi5 were mined from rice landrace collection from Karnataka state, India by using gene linked and gene based molecular markers. Landraces were field screened for blast resistance. Pi1 gene was tracked in 39 landraces accounting 46.98% gene frequency. Sixty landraces contained Pi2 and Pi5 gene with 72.28% gene frequency. Twenty landrace harboured all the three genes.