Genetic dissection of grain zinc, iron, and yield traits in a CIMMYT bread wheat mapping population to support...

Zinc and iron deficiencies are major global health issues, and wheat biofortification offers a promising solution. However, simultaneously improving grain zinc concentration (GZnC), grain iron concentration (GFeC), and yield-related traits remains challenging. This study used 198 F₆ recombinant inbred lines (RILs) derived from a cross between the high-zinc/iron parent 'Manku' and low-zinc parent 'Kachu' developed at CIMMYT, Mexico. The population was phenotyped for GZnC, GFeC, days to heading (DH), plant height (PH), thousand-kernel weight (TKW), and test weight (TW) over two growing seasons. QTL mapping using ICIM-ADD and multi-environment trial (MET) models identified 72 QTLs, with 23 stably expressed across both methods, including QGZnC.cim-7D, QTKW.cim-7B.2, and QDH.cim-5B. Notably, QTL clusters for GZnC/GFeC content and yield traits were found on chromosomes 2B, 5A, and 7D, indicating potential for synergistic improvement. Candidate gene prediction within six QTL intervals associated with GZnC and GFeC identified 17 genes involved in transport or homeostasis, such as zinc transporters, oligopeptide transporters, and glutathione S-transferases. Additionally, 15 promising lines (e.g., KM_618, KM_633, KM_782, KM_791) were selected for biofortification or simultaneous improvement of micronutrient content and yield. These stable QTLs provide a foundation for coordinated enhancement of grain nutrition and yield in wheat breeding.

The online version contains supplementary material available at 10.1007/s11032-026-01663-8.