Evaluation of pea accessions and commercial cultivars for fusarium root rot resistance

Fusarium root rot caused by Fusarium solani f. sp. pisi (Fsp) can result in major yield losses in pea (Pisum sativum L.). Currently no fungicides effectively manage this disease. Previous studies evaluated the Pisum germplasm collection for resistance to Fsp, however, evaluations of commercial market classes of pea cultivars grown in the US, and elsewhere, have not been reported. This study evaluated pea accessions and commercial cultivars for Fsp resistance under greenhouse conditions. Accessions evaluated included pigmented lines with high levels of partial resistance to Fsp. Based on root disease severity (RDS) values, the most Fsp-resistant Austrian winter, green fresh, green dry, yellow dry, green winter and yellow winter pea were: PI 125673, 5003, ‘Banner’, ‘Carneval’, PS 05300234, and ‘Whistler’, respectively. Genotypes with a RDS value of 3.05, on a 0–6 scale with 6 being severe, or less had no significant (P ≤ 0.05) reductions in plant height, shoot dry weight, and root dry weight, compared to non-inoculated controls, establishing an important disease threshold value for pea breeders. Plant height, more than shoot dry weight or root dry weight, was the most highly negatively correlated growth parameter related to RDS in repeated tests based on Pearson’s Correlation coefficients. However, root dry weight was also a highly sensitive growth parameter affected by Fsp since 14 of 33 genotypes had significant (P ≤ 0.05) reductions in root dry weight compared to non-inoculated controls, while only 5 of 33 genotypes had significant reductions in plant height and/or shoot dry weight in combined tests.