Improving nutritional and health-associated traits in Pisum sativum (pea)

Seed quality traits in pea have been studied historically at many levels, where their impact on improving the nutrition of farm animals was often a primary driver for research. More recently the adoption of pea and other pulse crops for producing widely consumed human foods, as a source of valuable nutrition for specialist diets, and as high-value ingredients for sports nutrition, has resulted in a demand for increased diversity among the profile of constituents that are deposited during seed development and stored within mature seeds.High-throughput screening of natural germplasm resources and mutagenized populations of pea has identified null variants for several seed proteins, including pea albumin 2, lectin, trypsin-chymotrypsin inhibitors and five classes of gene encoding vicilin proteins. A set of mutations derived by fast-neutron mutagenesis include large genomic deletions, of which at least two affect additional unrelated genes. Combinations of mutations are providing novel germplasm with major changes in protein composition, in turn impacting on protein digestibility and amino acid composition and with implications for nutritional and functional properties.New prospects for improving the nutritional profile of seed carbohydrates for food use are presented. Recent discoveries from human intervention trials have demonstrated the impact of changes in carbohydrate digestibility and pea seed structure on blood glucose levels. Advances in technologies for characterizing starch and cellular structure are facilitating the screening of pea germplasm and the identification of novel variants.The acceleration of breeding programmes using novel germplasm is now facilitated by advances in speed breeding, enabling rapid generation times which, when coupled with advances in selection, should reduce dramatically the cost and timescale for the development of new varieties.