Effective resistance genes to Bacterial Leaf Blight Disease of rice in Malaysia

Abstract

The Bacterial Leaf Blight (BLB) Disease caused by Xanthomonas Oryzae Pv oryzae (Xoo) was estimated to produce yield losses as high as 50% on susceptible rice varieties in Malaysia (Saad, 1995). A severe BLB outbreak on MR84 during 1982 to 1994 had caused an estimated loss of RM50 million (Saad, 1994). In 2013, another new BLB outbreak was reported in Sekinchan areas causing heavy loss to the farmers where more than 80% of the planting areas were affected. Currently, about 60% of major rice granaries in Malaysia are planted with MR220 CL2 variety and the remaining are planted with MR263 and MR219. All these varieties had disease scored at moderately susceptible (MS) in main seasons and susceptible (S) to highly susceptible (HS) in off seasons in the screening house for past 3 years. These varieties are considered as susceptible varieties which could lead to another BLB outbreak if usage prolonged.