During the development, lines targeting Pi19 or Pit were susceptible to all Philippine blast isolated and used for selection. Lines with Pik, Pik-m, Pik-h, Pik-p, Pi1, or Pi7 showed the same reaction pattern to the isolate of each other. Varieties with Piz, Piz-5 (Pi2) or Pish showed a wide spectrum of resistance to the Philippine isolates.