Development of rice introgression lines with brown planthopper resistance and KDML105 grain quality characteristics through marker-assisted selection

‘Khao Dawk Mali 105’ (KDML105), a Thai aromatic rice cultivar, has been accepted in markets as a prime jasmine rice with premium prices. It has been extensively used as a parental line to develop new cultivars for rainfed lowland areas in Thailand because of its favorable quality and fragrance. However, this cultivar is highly susceptible to brown planthopper (BPH), a phloem sap-feeding insect pest of rice. The main objective of this study was to combine KDML105 essential grain quality traits with BPH resistance from the donor cultivar, ‘Rathu Heenati’. The linkage drag between Bph3 and Wx^a alleles was successfully broken by phenotypic and marker-assisted selections. All introgression lines (ILs) developed in this study showed a broad spectrum resistance against BPH populations in Thailand and had KDML105 grain quality standards. Finally this study was revealed that the ILs can be directly developed into BPH resistant varieties or can be used as genetic resources of BPH resistance to improve rice varieties with the Wx^b allele in rice breeding programs.