Introduction

Field pea (Pisum sativum L.) is the most widely grown pulse crop in Canada where the yellow pea is the dominant market class. Field pea producers have consistent need for pea varieties with improved yield potential, better lodging resistance, improved disease resistance, and better seed quality. In this article, we provide details on the development and characteristics of AAC Julius, a yellow field pea variety recently developed at Agriculture and Agri-Food Canada (AAFC). The variety was registered on 5 February 2021 at the Variety Registration Office, Canadian Food Inspection Agency. The registration number was 9198.

Pedigree and breeding methods

AAC Julius was developed from the cross Agassiz/CDC1897-14. Agassiz is a yellow pea variety developed at AAFC (Bing et al. 2006). CDC1897-14, derived from the cross Miami/352-3-Y-2//Eclipse/458B-Y-5, was a breeding line developed at the Crop Development Centre, University of Saskatchewan. The breeding method for AAC Julius was pedigree selection in combination with single-seed descent for generation advance.

The cross Agassiz/CDC1897-14 was made in the greenhouse in the winter of 2008 at AAFC Lacombe Research and Development Centre (LRDC), AB. The F₁ generation was grown in the field in Morden, MB and Lacombe, AB in the summer of 2009, and the F₂ generation was grown in the field in 2010 in Lacombe AB. In total, 205 plants were harvested from the F₂ nursery, and then advanced to the F₃ generation in the greenhouse of AAFC LRDC and an off-season nursery in Brawley, CA, USA in the winter of 2010/2011 using a modified single-seed descent (mSSD) method, where a single pod was harvested from each plant, and one or more seeds were planted in the following generation. The F₄ and F₅ generations were grown in the field in Lacombe, AB in 2011 and 2012, and 209 and 344 plants were selected using mSSD, respectively. The F₆ generation was planted in the field in Lacombe, AB in 2013 and 110 single plants were harvested. In 2014, each of the harvested single plants from the F₆ generation was grown in 1m² plot in the field in Lacombe, AB. One entry designated as line P0937-4006 was selected on the basis of visual evaluation of maturity, pod canopy, and lodging resistance. P0937-4006 was evaluated in the replicated preliminary yield test-15 in 2015 in Lacombe, AB. In the test, P0937-4006 exhibited high yield potential, good lodging resistance, and good seed quality. In 2016, it was evaluated in the Net-4, a replicated yield test at seven locations in western Canada. The test locations were Barrhead, Rotation-K, Smirnoff, St. Albert, and Vegreville, AB, and Melfort and Saskatoon, SK. P0937-4006 demonstrated high yield (6908kgha^?1), good lodging resistance (5 on a 1–9 scale), small to medium seed size (1000-seed weight (TSW)�=�195g), and medium maturity (100days). Therefore, it was selected as a candidate for Western Canada Field Pea Cooperative Registration Test (Pea COOP Test). P0937-4006 was planted in two 1m × 15�m strips in the field in Lacombe, AB in 2017 for seed multiplication and purification by roguing off-type plants. It was entered into the 2018–2019 Pea COOP Test-B, and tested at a total of 26 location-years. The test locations were Fort St. John, BC; Barrhead, Brooks, Lacombe, St. Albert, and Vegreville, AB; Brandon, MB; and Indian Head, Limerick, Kamsack, Melfort, Saskatoon, Scott, and Swift Current, SK. On 5 February 2021, P0937-4006 was registered as variety AAC Julius at the Variety Registration Office of Canadian Food Inspection Agency.

Performance

In 2018–2019 Pea COOP Test-B, AAC Julius yielded 4138kgha^?1, 4% higher than the check cultivars CDC Amarillo and AAC Lacombe (Table�1). AAC Julius had a maturity of 100days, similar to the check varieties. It had a plant height of 83cm. AAC Julius had a preharvest lodging score of 3.6 on a 1–9 scale, similar to the check varieties.

Table 1.

Agronomic performance, seed quality, and disease resistance of AAC Julius and the check cultivars (CK) in the 2018–2019 Field Pea Cooperative Registration Test-B.

Maintenance and distribution of pedigreed seed

Breeder seed of AAC Julius was derived from a single line in the F₁₁ generation, and is maintained at AAFC Research Farm, Indian Head, SK S0G 2K0, Canada. Exclusive rights for the sale and production of the pedigreed seed for commercialization have been awarded to FP Genetics Inc., 426 McDonald Street, Regina, SK S4N 6E1, Canada and Riverside Communications Inc., PO Box 128, 6373 39th Street, Plaza, ND 58771, USA.