DArTseq-Based, High-Throughput Identification of Novel Molecular Markers for the Detection of Fusarium Resistance in Maize

Modern maize breeding worldwide relies on a broad range of molecular genetics research techniques. These technologies allow us to identify genomic regions associated with various phenotypic traits, including resistance to fungi of the genus <i>Fusarium</i>. Therefore, the aim of this publication was to identify new molecular markers linked to candidate genes that confer maize resistance to <i>Fusarium</i> fungi, using next-generation sequencing, association mapping, and physical mapping. In the study, a total of 5714 significant molecular markers related to maize plant resistance to <i>Fusarium</i> fungi were identified. Of these, 10 markers were selected that were significantly associated (with the highest LOD values) with the disease. These markers were identified on chromosomes 5, 6, 7, 8, and 9. The authors were particularly interested in two markers: SNP 4583014 and SilicoDArT 4579116. The SNP marker is located on chromosome 5, in exon 8 of the gene encoding <i>alpha-mannosidase I MNS5</i>. The SilicoDArT marker is located 240 bp from the gene for peroxisomal carrier protein on chromosome 8. Our own research and the presented literature review indicate that both these genes may be involved in biochemical reactions triggered by the stress caused by plant infection with <i>Fusarium</i> fungal spores. Molecular analyses indicated their role in resistance processes, as resistant varieties responded with an increase in the expression level of these genes at various time points after plant inoculation with <i>Fusarium</i> fungal spores. In the negative control, which was susceptible to <i>Fusarium</i>, no significant fluctuations in the expression levels of either gene were observed. Analyses concerning the identification of <i>Fusarium</i> fungi showed that the most abundant fungi on the infected maize kernels were <i>Fusarium poae</i> and <i>Fusarium culmorum.</i> Individual samples were very sparsely colonized by <i>Fusarium</i> or not at all. By using various molecular technologies, we identified genomic regions associated with maize resistance to <i>Fusarium</i> fungi, which is of fundamental importance for understanding these regions and potentially manipulating them.