한국 및 일본 균주에 대한 벼흰잎마름병 저항성 근동질 유전자 계통의 반응

Reaction of Near-Isogenic Lines with Resistance to Bacterial Blight to Korean and Japanese isolates of Xanthomonas oryzae pv. Oryzae

To develop durable and stable breeding strategies for the control of rice bacterial blight (BB) disease, the near-isogenic lines (NILs) with diverse resistance genes to BB isolates were evaluated in plant at three different growth stages using four Korean (K1, K2, K3, K3a) and three Japanese isolates (I, II, III). The resistance of the NILs to seven BB isolates tended to increase with plant aging. At the seedling stage, the NILs with single resistance genes were mostly resistant to K1 race but they showed partial or no resistance to other isolates. A NILs (IRBB5) possessing xa5 had full resistance to the four Korean isolates, illustrating that it is a useful source to give enhancement to Korean breeding program. At the maximum tillering stage, resistance of NILs to K2, K3, I and II isolates considerably increased while resistance to K1, K3a and III were similar to those of seedling stage. NILs with resistance gene of Xa4, xa5 and Xa7 proved to be the most stable to BB isolates at the maximum tillering stage. At the heading stage, most resistance genes of NILs were effective against BB isolates, and xa5 showed the consistent resistance to all the BB isolates including K3a and III isolates, demonstrating that resistance genes of Xa4, xa5 and Xa7 can be used either alone or combined to enhance resistance to BB disease in Korea.