Breeding new pea varieties that address the challenges and opportunities of the western Canadian industry is a key component to the success of this crop. This project was targeted at breeding high performance pea varieties for the Canadian prairies. It aimed to address all the key traits that have become desirable and expected in Canadian pea varieties including high grain yield, good lodging resistance, medium time to maturity, strong competitiveness with weeds, powdery mildew resistance, good resistance to the ascochyta/mycosphaerella blight complex, smooth seed coat, round seed shape, bright seed colour, low seed coat breakage score, and high protein concentration. In addition, this project placed an expanded emphasis on improving root rot resistance, since root rot has become an important constraint in pea production in western Canada in the past decade. This project used a combination of conventional and molecular breeding approaches to address the goals of the project.
The following CDC pea varieties were supported for variety registration over the course of this project: CDC 5517-7 (yellow), CDC 5633-2 (yellow), CDC 5523-7 (green), CDC 5779-1 (yellow), CDC 5947-4 (yellow), CDC 5928-6 (green), CDC 1513-2 (marrowfat), CDC 5856-3 (forage), CDC 6083-4 (yellow), CDC 6138-10 (yellow), CDC 6471-2 (yellow) and CDC 6482-4 (yellow). Of these, CDC 5779-1 was later registered as CDC Boundless and is being commercialized by SeCan, CDC 5947-4 was later registered as CDC Engage and is being commercialized by Alliance Seed, CDC 1513-2 is being commercialized by Rudy Agro, and CDC 6471-2 is being commercialized by SeCan. Additionally, the following CDC-bred pea varieties were nominated by Saskatchewan Pulse Growers/Limagrain for support for registration: 5791-9, 5845-2, 6020-11, 6087-11, 6121-9, 6138-1, 6232-4, and 6242-1. Of these, 5791-9 was later registered as CDC 5791 and is being commercialized by Canterra Seeds, and 5845-2 was later registered as CDC 5845 and is being commercialized by Alliance Seed. We expect that these new cultivars will contribute to the future success of the pea industry in western Canada.
We have identified new sources of resistance to Fusarium root rot and SNP markers associated with the resistance by screening a genome-wide association study panel (GWAS-2) of 233 pea accessions. Chr6LG2_68269711 is the most significant SNP marker associated with F. avenaceum resistance. New sources of Aphanomyces root rot resistance in GWAS-2 have been identified in a parallel project funded by ADF. In-house KASP assays were developed for routine testing of breeding lines for F. solani resistance based on the previously reported QTL Fsp-Ps2.1. We have developed a root rot nursery at USask for testing pea and lentil breeding lines. Progressive monitoring of the root pathogens of infected plants using microscopic and PCR observations established the increased soil population of A. euteiches and presence of several Fusarium pathogens in this disease nursery, making it well-suited for routine testing of breeding lines. The new sources of resistance and SNP markers identified in these studies will be used for marker-assisted introgression of root rot resistance in the CDC pea breeding program.

Extension Messages

• Five new yellow pea varieties and one new marrowfat pea variety arising from the CDC pea breeding program were commercialized over the course of this project.
• The yellow pea varieties bring improvements in grain yield, plus one or more of the following: improved seed protein concentration, improved resistance to lodging, improved resistance to seed coat breakage, greater competitiveness with weeds. The marrowfat pea variety is greater yielding than the relevant checks. All six varieties are resistant to powdery mildew.
• New sources of resistance to F. avenaceum have been identified in pea germplasm and breeding accessions. SNP markers associated with resistance were identified to support accelerated breeding of resistant cultivars.
• New sources of resistance to Aphanomyces root rot have been identified in parallel projects. SNP markers associated with Aphanomyces resistance have been identified and used to introgress disease resistance into early generation pea breeding lines.
  In-house KASP assays were developed for routine testing of pea breeding lines for F. solani resistance.