resources, and 2. monitoring the pathogen’s arsenal of effectors. Three Mediterranean landraces previously selected for their resistant response (Trinakria, Kyperounda, and Russello SG7) and representative of known landrace populations were crossed with the susceptible DW15811, Svevo, and Meridiano to originate recombinant inbred mapping populations. Major QTLs were found in all populations. Two QTLs were detected in the Trinakria/ DW 15811 population, four QTLs in the Russello/Svevo and six QTLs in the Kyperounda/Meridiano. Among the detected QTLs, five had a strong effect (r² > 10%) on chromosome 2A (in Russello), 3A (shared by Trinakria and Kiperounda), 5B (in Russello), 6A (shared by Russello and Kiperounda) and 6B (in Trinakria). In parallel, an exploratory association study was conducted on a panel of 300 tetraploid landraces, representative of 8 main T. turgidum populations that co-evolved with the pathogen. The panel was assessed in inoculated field nurseries in Po Valley (two years) and showed a continuous distribution for Infection Type (IT from 0 to 9), which will be leveraged to map and confirm bi-parental and novel QTLs and provide valuable donors. On the pathogen side, a highly diversified panel of 238 Z. tritici isolates from 8 European and Mediterranean countries were whole-genome sequenced and subjected to pathogenicity tests at seedling stage on hexaploid Chinese Spring, known to carry Stb6. On average, LD decayed fast in the Z. tritici panel (0.420 kbp to LD at r2 = 0.2), thereby being instrumental in detecting candidate genes. Five major QTLs (LOD ≥ 5 and r2 ≥ 10%) were detected for the percentage of leaf surface covered by lesions (PLACL) and three QTLs for the pycnidia density in lesions (PycLes). Collectively, these results represent a substantial advance in elucidating the interplay between wheat and Z. tritici. We showed that (i) several novel resistance loci were found in landraces, and (ii) a range of potential pathogenicity factors were identified. These results can be leveraged to develop an integrated strategy towards achieving the Green Deal objectives. Acknowledgements: This research was supported in France by FSOV 2020 R “DURABLÉ” (2021- 2024) and INRAE SPE “BASTAFUN” (2023-2025), and by ERA-NET SusCrop FACCE JPI “WHEATSECURITY” (2023-2026), and by “INNOVAR” (2019-2024).
De Sario, F., Benbernou, R., Ntakirutimana, F., Lapalu, N., Gie Blé Dur, ., Ammar, K., et al. (2024). GENETICS AND GENOMICS OF THE WHEAT-ZYMOSEPTORIA TRITICI PATHOSYSTEM: NOVEL RESISTANCE GENE LOCI IN WHEAT AND INSIGHTS FROM PATHOGENICITY FACTORS.
GENETICS AND GENOMICS OF THE WHEAT-ZYMOSEPTORIA TRITICI PATHOSYSTEM: NOVEL RESISTANCE GENE LOCI IN WHEAT AND INSIGHTS FROM PATHOGENICITY FACTORS
DE SARIO F.;PRODI A.;CONFORTINI A.;BOZZOLI M.;STEFANELLI S.;TUBEROSA R.;MACCAFERRI M.
;
2024
Abstract
resources, and 2. monitoring the pathogen’s arsenal of effectors. Three Mediterranean landraces previously selected for their resistant response (Trinakria, Kyperounda, and Russello SG7) and representative of known landrace populations were crossed with the susceptible DW15811, Svevo, and Meridiano to originate recombinant inbred mapping populations. Major QTLs were found in all populations. Two QTLs were detected in the Trinakria/ DW 15811 population, four QTLs in the Russello/Svevo and six QTLs in the Kyperounda/Meridiano. Among the detected QTLs, five had a strong effect (r² > 10%) on chromosome 2A (in Russello), 3A (shared by Trinakria and Kiperounda), 5B (in Russello), 6A (shared by Russello and Kiperounda) and 6B (in Trinakria). In parallel, an exploratory association study was conducted on a panel of 300 tetraploid landraces, representative of 8 main T. turgidum populations that co-evolved with the pathogen. The panel was assessed in inoculated field nurseries in Po Valley (two years) and showed a continuous distribution for Infection Type (IT from 0 to 9), which will be leveraged to map and confirm bi-parental and novel QTLs and provide valuable donors. On the pathogen side, a highly diversified panel of 238 Z. tritici isolates from 8 European and Mediterranean countries were whole-genome sequenced and subjected to pathogenicity tests at seedling stage on hexaploid Chinese Spring, known to carry Stb6. On average, LD decayed fast in the Z. tritici panel (0.420 kbp to LD at r2 = 0.2), thereby being instrumental in detecting candidate genes. Five major QTLs (LOD ≥ 5 and r2 ≥ 10%) were detected for the percentage of leaf surface covered by lesions (PLACL) and three QTLs for the pycnidia density in lesions (PycLes). Collectively, these results represent a substantial advance in elucidating the interplay between wheat and Z. tritici. We showed that (i) several novel resistance loci were found in landraces, and (ii) a range of potential pathogenicity factors were identified. These results can be leveraged to develop an integrated strategy towards achieving the Green Deal objectives. Acknowledgements: This research was supported in France by FSOV 2020 R “DURABLÉ” (2021- 2024) and INRAE SPE “BASTAFUN” (2023-2025), and by ERA-NET SusCrop FACCE JPI “WHEATSECURITY” (2023-2026), and by “INNOVAR” (2019-2024).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
