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

Abstract 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 genotypes 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 × L) interaction VC were the main sources of variation for all the considered traits, with G × Y × L being strongly affected by the different climatic conditions which characterized the two test years. A further dissection of the genotype by environment interactions (GEI) through Additive Main effects and Multiplicative Interaction (AMMI), highlighted pea cultivars which outperformed the reference Norwegian variety Ingrid both in term of yield, protein content and protein yield. 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. Overall, this work identified pea genotypes which can be successfully grown in Norway and used as source of genetic diversity for future breeding efforts targeting the Norwegian environment.