Resistance to early blight in potato
J. WOLTERS (1), G. Bijsterbosch (2), R. Visser (2), G. van der Linden (2), V. Vleeshouwers (2) (1) Wageningen UR, Netherlands; (2) Wageningen UR, Netherlands

The fungal pathogen Alternaria solani causes early blight in potato. Early blight is most severe on early maturing cultivars, senescing plants, and plants that are stressed, for example by poor nutrition or drought. The disease is an increasing problem in the US, and A. solani strains are emerging that are resistant to most fungicides. No potato cultivars have been identified that are fully resistant to early blight. In order to identify sources of resistance against early blight, we screened a large collection of wild potato species (Solanum section Petota) and identified genotypes with high levels of resistance to A. solani. We are currently crosssing susceptible and resistant genotypes for subsequent genetic mapping studies to identify plant genes that are responsible for  the resistance against early blight. In parallel, we are studying the pathogen side. We sequenced the genome of A. solani using PacBio technology, resulting in a complete, gapless assembly of all 10 chromosomes. In addition, we are carrying out the analysis of the transcriptome of A. solani in vitro and in infected plant tissue. We aim to compare genomes of various Alternaria species and predict putative effectors of A. solani. These effectors will be subjected to functional tests in potato plants and their role in susceptibility or resistance to early blight will be studied.  Ultimately, the results from this study will be used to develop potato cultivars that are resistant to early blight.

Abstract Number: P17-638
Session Type: Poster