Improving preharvest sprouting resistance in durum wheat with bread wheat genes

Preharvest sprouting (PHS) of durum wheat (Triticum turgidum ssp. durum (Desf.) Husn.) is an important problem in Japan, where the rainy season overlaps with the harvest season. Since there are few PHS-resistant genetic resources in durum wheat, we introduced an R-gene for red seeds, the MFT gene, and the QPhs-5AL QTL, all of which are associated with PHS resistance, into durum wheat from a PHS-resistant bread wheat (T. aestivum L.) cultivar, ‘Zenkoujikomugi’ (Zen), by backcross breeding. Developed near isogenic lines (NILs) with red seeds had a lower percentage germination (PG) and germination index (GI) than the recurrent parent, and seed color had the greatest effect. A NIL combining all three sequences had the lowest GI and PG, with a similar GI to that of ‘Shiroganekomugi’ bread wheat. Among NILs with white seeds, a NIL combining MFT and QPhs-5AL had the lowest GI and PG. As the combination of all three sequences from Zen conferred PHS resistance on durum wheat, PHS-resistant genetic resources in bread wheat can be used in breeding durum wheat.