P-263 - Exploring potato genetics for soft rot and blackleg disease resistance

Potato, a clonally propagated crop, presents complex genetic challenges due to its ploidy level, complicating the understanding of key traits like resistance to bacterial soft rot and blackleg disease. These diseases cause significant crop losses in the field and storage, often leading to outbreaks with no efficient management options. In this study, we use Solanum chacoense M6 to investigate the genetics of important disease resistance traits. This line is ideal for our research as it has a publicly available genome, exhibits resistance to soft rot and blackleg, is self-fertile, and is homozygous for up to 87% of its genes. We generated a randomly mutagenized population of 272 M6 potato lines using ethyl methanesulfonate (EMS), and each was self-crossed to create segregation for mutated genes. These sub-populations were screened by inoculating them with Dickeya dianthicola ME23, followed by lesion measurement and decay weight recordings. Preliminary findings revealed a range of responses where resistant lines developed suberized lesions with minimal decay, while susceptible lines exhibited water-soaked necrosis and tissue maceration, indicating complete susceptibility. These observations suggest genetic modifications introduced through EMS mutagenesis influenced M6 disease resistance traits, including soft rot resistance, for which we previously lacked genetic information. Our future work aims to screen these lines against other potato diseases and sequence them to identify candidate genes and validate findings.