Analyses of phenotypic and genomic based genetic diversity highlight useful trait variation for the improvement of grain and protein yield of pea (Pisum sativum L.) grown in Norway

Pea ( Pisum sativum L.) plays a central role for achieving the goal of increased self-sufficiency of plant-based protein for food and feed in Norway. This study characterized 36 pea cultivars of mainly Nordic and eastern European origin grown in a multi-environment field trial in Norway for various agronomic traits including grain and protein yield. The same accessions were also genotyped with a single nucleotide polymorphism (SNP) chip array to investigate the genetic diversity both at the phenotypic and genomic levels. Variance component (VC) analyses found that genotype (G) and genotype by year by location (G × Y x L) interaction VC were the main sources of variation for all the considered traits, with G x Y x L being strongly affected by the different environmental conditions which characterized the two test years. Measurements of genetic distance based on phenotypic and genomic data were significantly correlated and distinguished the material in three main clusters which were partially associated with their geographic origin. This study identified pea cultivars which outperformed the reference Norwegian variety Ingrid both in term of grain and protein yields, which can be successfully grown in Norway and used as source of genetic diversity for future breeding efforts targeting the Norwegian environment.