Breeding of FHB-resistant wheat line Bainong 4299 by gene pyramiding

Fusarium head blight（FHB） is a devastating fungal disease in wheat production. Wheat FHB resistance is controlled by multiple genes and has complicated resistance mechanisms. Type Ⅰ（resistance to invasion） and type Ⅱ（resistance to expansion）are two main resistance types of wheat against FHB. Combining both types of FHB resistance in breeding is vitally important for the resistance durability and stability of cultivars. In fine mapping and cloning of type Ⅰ resistance QTL Fhb4 and Fhb5 and type Ⅱ resistance QTL Fhb1 in wheat landrace Wangshuibai, functional/tightly-linked molecular markers for them had been obtained. In this study, a new wheat line named Bainong 4299 was bred after introduction of these QTL from NMAS022 with the help of these markers and using modern wheat variety Bainong 4199 as the recipient parent. Compared with Bainong 4199, Bainong 4299 increased type Ⅰ resistance by at least 73% to 74% and type Ⅱ resistance by 83% to 88% increase（in terms of the number of diseased spikelets per spike） in