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Genetic identification of loci for Hessian fly resistance in durum wheat
- Bassi, F. M., Brahmi, H., Sabraoui, A., Amri, A., Nsarellah, N., Nachit, M. M., Al-Abdallat, A., Chen, M. S., Lazraq, A., El Bouhssini, M.
- Molecular breeding 2019 v.39 no.2 pp. 24
- Mayetiola destructor, Triticum turgidum subsp. dicoccon, Triticum turgidum subsp. durum, biotypes, chromosome mapping, cultivars, disease outbreaks, durum wheat, genes, genetic resistance, introgression, loci, marker-assisted selection, pests, quantitative trait loci, telomeres, Northern Africa
- Durum wheat (Triticum durum Desf.) is a major crop of North Africa. Here, its production is affected by Hessian fly (Mayetiola destructor, HF) epidemics. Genetic resistance against this pest exist, but its molecular basis remains unclear. Here, a panel of 159 modern durum lines were exposed to the Moroccan HF biotype. Association mapping studies revealed three major loci conferring resistance. QH.icd-2A was identified at LOD of 24.1 on the telomeric end of 2AL, and it is believed to represent a novel locus derived from T. dicoccum. QH.icd-5B was identified on 5BS at LOD of 9.5, and it appears as overlapping with H31. QHara.icd-6B was identified at LOD of 54.5. This locus confers resistance to five Moroccan released cultivars, including ‘Faraj’. A mapping population (MP) was obtained by crossing ‘Faraj’ and a HF-susceptible cultivar ‘Gidara2’. Challenging this MP with the Moroccan and Great Plains HF biotypes revealed 1:1 segregation ratio fitting of a single gene. Quantitative trait locus (QTL) analysis confirmed a single locus at LOD of 35 and 25 for the two biotypes, respectively, corresponding to QHara.icd-6B. This locus spans a 7.7 cM interval, and it is derived via introgression from a resistant T. araraticum. One KASP marker (BS00072387) was validated for use in breeding on a separate set of elite lines, to show r² of 0.65 and accuracy of 0.98. Finally, field testing across sites did not identify any yield drag for QHara.icd-6B. The work presented here provides ideal tools to incorporate HF-resistant loci in durum cultivars via marker-assisted breeding.