Reaction of Resistance Genes of Monogenic Lines to Rice Blast (Magnaporthe grisea)

This study was done to get the information for the effect of single genes to the inoculation of Korean blast isolates and in the field condition using a set of monogenic lines of LTH (Lijianxintuanheigu, a Chinese japonica susceptible rice). Seven monogenic lines, IRBLa−A of Pia, IRBLk−Ka of Pik, IRBLkp−K60 of Pikp, IRBLta−K1 of Pita, IRBLt−K59 of Pit, IRBLsh−B of Pish, and IRBL19−A of Pi19(t), showed a susceptible reaction to over 80% isolates used. Four monogenic lines, IRBLz5−CA of Piz5, IRBLzt−T of Pizt, IRBL5−M of Pi5(t), and IRBL9−W of Pi9(t) showed the resistance reaction to 23~28 isolates screened. Five lines, IRBLks−S, IRBLz5−CA, IRBLzt−T, IRBL5−M, IRBL9−W and Reiho showed the resistance or moderately resistance across regions and years in blast nursery test. Ten lines, IRBLks−F5, IRBLkh−K3, IRBLz5−CA, IRBLzt−T, IRBL1−CL, IRBL5−M, IRBL7−M, IRBL12−M, Tsuyuake of Pikm and Reiho of Pita2 showed less than 1% incidence of the leaf blast at the paddy field and no incidence of neck blast for two years. The monogenic lines of Pia, Pik, Pikp, Piz, Pita, Pit, Pish, Pi3(t), and Pi19(t) showed susceptible reactions at blast nursery and high incidence to leaf and neck blast in the paddy field. IRBLz5−CA (Piz5), IRBLzt−T (Pizt), and IRBL5-M (Pi5(t)) showed the stable resistance to blast isolates inoculation and to the evaluation at the field screening and thus will be useful to diversify gene source for stable and broad-spectrum resistance to Korean blast isolates in rice breeding program for blast resistance.