Mapping of Quantitative Trait Loci for Traits linked to Fusarium Head Blight Symptoms Evaluation in Barley RILs

Fusarium head blight (FHB) is a devastating disease in small grain cereals worldwide. The disease results in the reduction of grain yield and affects its quality. In addition, mycotoxins accumulated in grain are harmful to both humans and animals. It has been reported that response to pathogen infection may be associated with the morphological and developmental characteristics of the host plant, e.g. the earliness and plant height. Despite the many studies the effective markers for the selection of barley genotypes with increased resistance to FHB have not thus far been developed. Therefore, exploring the genetic relationship between agronomic traits (e.g. heading date or stem height) and disease resistance is of importance to the understanding of plant resistance via \"diesease escape\" or dwarf stature. The studied plant material consisted of 100 recombinant inbred lines (RIL) of spring barley. Plants were examined in field conditions (three locations) in a completely randomized design with three replications. Barley genotypes were artificially infected with spores of Fusarium before heading. Apart from the main phenotypic traits (plant height, spike characteristic, grain yield) the infected kernels were visually scored and the content of deoxynivalenol (DON) mycotoxin was investigated. A set of 70 Quantitative Trait Loci (QTLs) were detected through phenotyping of the mapping population in field condition and genotyping using a barley Ilumina iSelect platform with 9K markers. Six loci were detected for FHB index on chromosomes 2H, 3H, 5H and 7H. The region on the short arm of the 2H chromosome was detected in the current study, in which many QTLs associated with FHB- and yield-related characters were found. This study confirms that agromorphological traits are tightly related to the FHB and should be taken into consideration when breeding barley plants for FHB resistance.