Association of Fhb1 and Qfhs.ifa-5A in Spring versus Winter Growth Habits in Bread Wheat (Triticum aestivum L.)

Abstract

Fusarium head blight (FHB) is a major disease that reduces grain yield and quality of winter and spring wheat in eastern South Dakota. This study was conducted to determine the association of FHB resistance QTLs (Fhb1 and Qfhs.ifa-5A) to spring and winter growth habits of bread wheat. Four genotypes consisting of susceptible winter wheats 'Nekota' and '2137' and moderately resistant spring wheats 'ND2710' and 'BacUp' were crossed and populations derived from the crosses were separated into spring and winter types following cold treatment of seedlings at -7°C for 1 h. A total of six SSR markers (Fhb1 markers: Xgwm389, Xgwm493 and STS256; Qfhs.ifa-5A markers: Xgwm293, Xgwm304 and Barc186) were used to genotype the populations. A chi-square analysis deviating from a 1:1 ratio showed that there were significant differences in the percentage of genotypes containing homozygous marker alleles for Fhb1 and Qfhs.ifa-5A between spring and winter types in the population ND2710/2137, ND2710/Nekota and BacUp/2137. The percentage of genotypes with homozygous marker alleles for Fhb1 was lower in the spring types in the populations ND2710/2137 and ND2710/BacUp. In contrast, the spring types in the population ND2710/Nekota had a higher percentage of genotypes containing homozygous marker alleles for Qfhs.ifa-5A compared with the winter types. The results indicated that Fhb1 was not necessarily associated with the spring growth habit; whereas, Qfhs.ifa-5A was not necessarily associated with the winter growth habit.