Identification and Validation of Blast Resistance Loci from the Durable Resistance Cultivar Hahng Yi 71
Authors:   Interdisciplinary Graduate Program in Genetic Engineering, Graduate School, Kasetsart University, Bangkok 10900, Thailand, Plabpla Anucha , Korinsak Siriporn ,   National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand, Korinsak Siripar ,   National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand, Thunnom Burin ,   National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand, Vanavichit Apichart ,   Department of Agronomy, Faculty of Agriculture at Kamphaeng Saen, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom, 73140, Thailand, Saleeto Somjai ,   Sakon Nakhon Rice Research Center, Nittayo Rd., That Choeng Chum, Mueang Sakon Nakhon, Sakon Nakhon 47000, Thailand, Sirithanya Kanyanat ,   Faculty of Science and Agricultural Technology, Rajamangala University of Technology Lanna, Chiang Mai, 50300, Thailand, Toojinda Theerayut ,   National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand
Published: September 2024

One of the effective strategies for developing blast disease-resistant cultivars to mitigate the yield losses caused by Pyricularia oryzae is the discovery of new genetic resources containing resistance genes. In the present study, a Thai landrace glutinous rice cultivar Hahng Yi 71 (HY71) was used as a durable, broad resistance source to identify QTLs against blast fungus and crossed with a susceptible recurrent parent cultivar RD6, generating 56 BC4F5 lines. The BC4F5 population was tested with six blast isolates, including THL54, THL583, THL658, THL690, THL795, and THL1119, and evaluated with 161 SSR markers to identify resistance regions using modified bulk segregation analysis. Single marker analysis showed 7 markers linked to a resistance reaction located on chromosomes 2, 4, and 5, then tentatively designated as qBL2-RD6, qBL4-HY71, and qBL5-HY71, respectively. Two introgressed lines from the mapping population, KKN97057-7-1-1-2-5-NKI-4-1 and KKN97057-7-1-1-2-5-NKI-5-1, were the qBL5-HY71 donor for introgressing into two rice lines, RGD07123-MS12-MS22-MS1, and RGD07123-MS12-MS22-MS9, which generated two single crosses and a backcross population by marker-assisted selection (MAS) using the linked markers RM39 and RM164. Three improved lines, RGD10021-MS18-B-MS8-MS40, RGD10031-MS-MS3-B-MS9-MS42 (single cross), and RGD11086-MS-MS15-MS10-MS19 (backcross), carrying qBL5-HY71, were tested for their resistance against leaf and neck blast disease by 62 and 8 blast isolates, respectively. The disease screening results showed that qBL5-HY71 was very effective in controlling leaf and neck blast. This study demonstrates the effectiveness of resistance loci qBL5-HY71 from HY71 on chromosome 5 and their linked markers in improving durable blast resistance in rice breeding programs.