DISCOVERY OF TWO NEW QUANTITATIVE TRAIT LOCI FOR BROWN PLANTHOPPER RESISTANCE IN RICE, ORYZA SATIVA

Abstract

The brown planthopper (BPH) is the leading cause of insect damage to rice plants. Native BPH resistance in rice has broken down over the years. Therefore, there is an urgent need to discover new BPH resistance genes to ensure successful production of rice. A new BPH resistance source provided by SeedWorks International Pvt. Ltd., SWD10, was used for this purpose. QTL mapping using 234 F2 progenies and 216 polymorphic markers revealed 2 major dominant QTLs located on chromosome 4. Fine mapping and subsequent RNA-Seq analysis of the newly identified QTLs identified 7 potential gene candidates. Furthermore, tests for BPH resistance mechanism revealed that antibiosis and antixenosis together play a role in BPH resistance conferred by the newly identified QTLs. Based on our results, the 2 newly identified QTLs are different from the previously cloned QTL. The newly identified QTLs are currently being explored for breeding BPH resistant rice varieties.