Identification of a pleiotropic QTL cluster for Fusarium head blight resistance,spikelet compactness,grain number per spike and thousand-grain weight in common wheat

Simultaneously improving Fusarium head blight(FHB)resistance and grain yield is challenging in wheat breeding.The correlations between spikelet compactness(SC),grain number per spike(GNS),thousandgrain weight(TGW)and FHB resistance remains unclear in common wheat.Identification of major quantitative trait loci(QTL)conferring FHB resistance and yield components,and development of breeder-friendly markers for the QTL are prerequisites for marker-assisted selection(MAS).Here,a recombinant inbred line(RIL)population derived from a cross between a resistant cultivar Yangmai 12(YM12)and a susceptible cultivar Yanzhan 1(YZ1)was used to map QTL for FHB resistance and yield components.A total of 22 QTL were identified;among these,six are likely to be new for corresponding traits.A QTL cluster(Qclu.yas-2D)for FHB type II resistance,SC,GNS,and TGW was detected on chromosome 2D.Breeder-friendly kompetitive allele-specific PCR(KASP)markers flanking the interval of Qclu.yas-2D were developed and validated in a diverse panel of 166 wheat cultivars and advanced lines.The YM12 alleles of Qclu.yas-2D significantly increased FHB resistance,SC,and GNS but decreased TGW in the validation population.The KASP markers developed for Qclu.yas-2D have great potential for breeding high-yielding wheat cultivars with enhanced FHB resistance.

Breeding for the resistance to Fusarium head blight of wheat in China

With the changes of climate and cultivation systems, the Fusarium head blight(FHB) epidemic area in China has extended since 2000 from the reaches of the Yangtze River to the north and west winter wheat region.Breeding for FHB resistance in wheat is an effective way to control the disease.Chinese wheat breeders commenced research on FHB in the 1950 s.Sumai 3, Ning 7840,Yangmai 158, Ningmai 9 and other cultivars with improved FHB resistance were developed through standard breeding methods and widely applied in production or breeding programs.In addition to intervarietal crosses,alien germplasm was used to improve FHB resistance of wheat.Addition, substitution and translocation lines with alien chromosomes or chromosome fragments were created to enhance FHB resistance.Somaclonal variation was also used to develop a FHB resistant cv.Shengxuan 3 and other cultivars with moderate resistance to FHB were released by such methods.QTL(quantitative trait loci) for FHB resistance were characterized in cultivars originating from China.The major QTL, Fhb1, was identified on chromosome 3 BS in Sumai 3, Ning 894037, Wangshuibai and other Chinese resistant sources.Diagnostic molecular markers for Fhb1 have been applied in wheat breeding and breeding lines with improved FHB resistance and desirable agronomic traits have been obtained.However, breeding for FHB resistance is a long-term task, new technologies are likely to increase the efficiency of this process and better FHB resistance of new cultivars is expected to be achieved within the next decade.

Highlights of special issue on “Wheat Genetics and Breeding”

Wheat is one of the world’s most important food crops and a major constituent of daily calorie and protein intake in humans,thus maintaining sustainable development of wheat production is a globally important issue,particularly for less developed countries.Producing more wheat with better nutrition using less inputs,has become a common objective both for producers and consumers.