Genetics of brittleness in wild, domesticated and feral einkorn wheat (Triticum monococcum L.) and the place of origin of feral einkorn

The status of Triticum boeoticum subsp. aegilopoides (Link) Schiem. is somehow confusing, suggesting a need to verify whether this subspecies is a truly wild or a feral form. After reviewing some rather inaccessible older literature, a half-diallel of three pure einkorn lines (truly wild, domesticated and aegilopoides) was performed. The F2 and F3 analyses of brittleness and microscope-based studies of the abscission scars on rachis fragments were combined with extant genome maps. Two QTL segregated in the cross domesticated × wild (one on chromosome 4 and one on chromosome 7), but only one segregated in the cross feral × wild (same as before on chromosome 7), indicating that the feral form carried a wild (or equivalent) allele. Within the cross domesticated × feral, quantitative segregation occurred and could be caused by some neat abscission scars, but without the typical ‘fish-mouth-like’ appearance of the truly wild form. We suggest that aegilopoides and domesticated einkorn emerged in patches of semi-brittle mutants in the Karacadag Mountains and were collected and maintained by humans. When agriculture moved from South-East Turkey into Western Turkey and later into the Balkans, aegilopoides became the feral form we know today, characterized by a semi-brittle rachis that makes it less wild compared to the truly wild Triticum boeoticum subsp. thaoudar (Reut. ex Hausskn.) Grossh.