| Description: |
Triticale (x Triticosecale Wittmack) is a potential alternative to other small cereals since it is a double-purpose grain and forage crop, thriving even on marginal soils with lower nutrient inputs. Since its introduction, triticale has been considered a healthier option than its progenitors. However, with its introduction in cultivation, triticale has begun to show susceptibility to several fungal diseases, including powdery mildew, fusarium head blight, septoria leaf blotch, and rust, adversely affecting yield and grain quality. One of the primary goals of triticale breeding is to develop resistance to these diseases, such as yellow rust, caused by the pathogen Puccinia striiformis f. sp. tritici (Pst), which is recognized as one of the top 10 crops fungal pathogen (Dean et al., 2012), and new aggressive isolates began to spread. In this study, 280 triticale genotypes, 112 commercial varieties, and 170 breeding lines were cultivated over two to three seasons at five locations. To ensure uniform infection, the plots were surrounded by a highly susceptible triticale cultivar. The accessions were primarily evaluated for their tolerance/susceptibility to yellow rust. Still, other interesting phenotypic traits not influenced by the disease were recorded, such as soil cover, plant height, and flowering time. Genetic variation was assessed using DArT (Diversity Arrays Technology) markers. The final number of single nucleotide polymorphisms (SNPs) included in the study after filtering was around 15’000. Those were aligned to a synthetic triticale genome, constructed from the A and B subgenomes of the IWGSC wheat cultivar ‘Chinese Spring’ v2.1 and the R genome of the rye inbred line ‘Lo7’ v3. Later, the SNPs were used to assess the population structure and associated with the phenotypic traits, and a genome-wide association study (GWAS) was performed. |