Location: Dale Bumpers National Rice Research Center
Title: Mapping blast resistance genes in rice varieties ‘Minghui 63’ and ‘M-202’Author
Jia, Yulin | |
Jia, Melissa | |
YAN, ZHONGBU - Texas A&M Agrilife |
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/3/2021 Publication Date: 3/30/2022 Citation: Jia, Y., Jia, M.H., Yan, Z. 2022. Mapping blast resistance genes in rice varieties ‘Minghui 63’ and ‘M-202’. Plant Disease. https://doi.org/10.1094/PDIS-09-21-2095-RE. DOI: https://doi.org/10.1094/PDIS-09-21-2095-RE Interpretive Summary: Rice blast disease is one of the most lethal diseases for sustainable rice production worldwide, and major disease resistance genes are often broken down shortly after deployment. Minor blast resistance genes are more durable than major blast resistance genes. We evaluated disease reactions of two rice breeding parents ‘Minghui 63’ and ‘M-202’ with eleven common US blast races: IA45, IB1, IB45, IB49, IB54, IC1, IC17, ID1, IE1, IG1, and IH1 to find minor blast resistance genes. A recombinant inbred line (RIL) population derived from a cross of these parents was evaluated with the same blast races and analyzed with 156 simple sequence repeat (SSR) and insertion and deletion (Indel) genetic markers distributed on all 12 rice chromosomes. Eight resistance QTLs from ‘Minghui 63’ and two resistance QTLs from ‘M-202’ were mapped, and 16 blast resistant lines were identified as genetic stocks. One resistance QTL, qBLAST2, on rice chromosome 2 was identified providing resistance to seven blast races. The remaining resistance QTLs were mapped on rice chromosomes 1, 3, 6, 9, 10, 11 and 12. These findings supply useful genetic markers and resources for marker assisted selection in rice breeding programs. Technical Abstract: Rice blast disease caused by the fungus Magnaporthe oryzae (syn. M. grisea) is one of the most lethal diseases for sustainable rice production worldwide. Blast resistance mediated by major resistance genes are often broken-down after a short period of deployment, while minor blast resistance genes, each providing a small effect on disease reactions, are more durable. In the present study, we first evaluated disease reactions of two rice breeding parents ‘Minghui 63’ and ‘M-202’ with 11 US blast races, IA45, IB1, IB45, IB49, IB54, IC1, IC17, ID1, IE1, IG1, and IH1 commonly found under greenhouse conditions using a category disease rating resembling infection types under field conditions. ‘Minghui 63’ exhibited differential resistance responses in comparison with that of ‘M-202’ to the tested blast races. A recombinant inbred line (RIL) population of 275 lines from a cross between ‘Minghui 63’ and ‘M-202’ was also evaluated with the above mentioned blast races. The population was genotyped with 156 simple sequence repeat (SSR) and insertion and deletion (Indel) markers. A linkage map with a genetic distance of 1022.84 cM was constructed using inclusive composite interval mapping (ICIM) software. A total of 10 resistance QTLs, eight from ‘Minghui 63’ and two from ‘M-202’, were identified. One major QTL, qBLAST2 on chr 2, was identified by seven races/isolates. The remaining nine minor resistance QTLs were mapped on chromosome 1, 3, 6, 9, 10, 11 and 12. These findings will provide useful genetic markers and resources to tag minor blast resistance genes for marker assisted selection in rice breeding program and for further studies of underlying genes. |