Optimization of breeding methods when introducing multiple resistance genes from American to Chinese wheat
Stripe rust is one of the most destructive diseases of wheat worldwide. Growing resistant cultivars with resistance genes is the most effective method to control this disease. QuLine is a computer tool capable of defining genetic models, breeding strategies and predicting parental selection using known gene information. This paper reports the breeding process for pyramiding resistance genes to stripe rust using genetic information of American cultivars Aplowa (P1), Louise (P2), Express (P3) and Chinese cultivar Zhoumai18 (P4). The breeding objective was to transfer the stripe rust (SR) resistance genes from the three American lines to the elite Chinese wheat, without reducing its desired agronomic performance (AT). Results show that double crosses (P4×P1)//(P4×P2), (P4×P1)//(P4×P3) and (P4×P2)//(P4×P3) were efficient in improving genetic gains on traits AT and SR in selection strategy AHA, while only in HAH, cross combination (P4×P3) // (P1×P2) had the highest genetic gains on high-temperature, adult-plant resistance (HTAP). The results in this study could be important in targeted breeding for efficiently pyramiding more resistance genes to stripe rust, avoiding simplified resistance genes, and breeding novel varieties.
Key words: Breeding methods, wheat, resistance, genes.