QTL Associated with Partial Resistance to Root Rot of Field Pea Caused by Aphanomyces euteiches and Fusarium...

Deployment of polygenetic resistance is a promising approach for minimizing losses caused by the root rot complex of pea (Pisum sativum). Previous studies have identified quantitative trait loci (QTL) associated with partial resistance to Aphanomyces euteiches and Fusarium graminearum on chromosome 4/linkage group (LG) IV. The objective of this study was to identify consistent QTL associated with resistance to A. euteiches and F. avenaceum in two recombinant inbred line (RIL) populations derived from 'Reward' × '00-2067' (RIL-1) and 'Carman' × '00-2067' (RIL-2). RIL-1 was inoculated with F. avenaceum, and RIL-2 with both A. euteiches and F. avenaceum. Plant height, plant vigor, and root rot severity were assessed across three repeated greenhouse experiments. A 13.2K single nucleotide polymorphism array and 222 simple sequence repeat markers were used to genotype the two RIL populations. Thirty QTL were mapped on two separate genetic maps. A highly consistent region located on chromosome 2/LG II, encompassing the previously identified QTL Ae-Ps2.2 and Fsp-Ps2.1, had a major effect on resistance to A. euteiches and F. avenaceum (individual QTL R² = 8 to 51%). One or more QTL associated with resistance to A. euteiches and F. avenaceum were linked to the previously identified genes Ae-Ps4.5 & Fwn4.1 and Ae-Ps4.1, respectively. These findings provide valuable targets for marker-assisted selection and can accelerate the development of pea cultivars with broad-spectrum resistance to root rot, thereby enhancing crop productivity and sustainability.