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ARS Home » Pacific West Area » Pullman, Washington » Grain Legume Genetics Physiology Research » Research » Research Project #442987

Research Project: Increasing the Concentration of Sulfer Containing Amino Acids (SCAA) in Pulse Crops

Location: Grain Legume Genetics Physiology Research

Project Number: 2090-21000-038-007-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 1, 2022
End Date: Aug 31, 2026

Pulse crops, including pea and chickpea, are an important source of plant-based protein to human diets across the world. However, protein-energy malnutrition of children caused by inadequate dietary protein consumption is prevalent in South Asia and sub-Saharan Africa, regions where chickpea has historically served as a major food crop. In addition to consumption of whole seed, over the past decade the production of "plant-based" food and beverages has increased several fold. Protein derived from pulse crops, especially pea, is widely used as ingredients in plant-based food products. However, relative to cereal grains such as wheat and barley, the concentration of methionine, an essential sulfur containing amino acid (SCAA), is low in pulse crops. Low concentrations of methionine directly result in low concentrations of another SCAA, cysteine, in pulse proteins. Developing new crop cultivars with improved nutritional qualities has been widely proposed to alleviate malnutrition and produce more nutritious plant-based foods and beverages. Improving traits through plant breeding requires heritable sources of variation for traits of interest. The relative magnitude of genetic (G), environment (E), and G x E interaction effects on traits must also be determined to efficiently develop stably performing cultivars. The objectives of this research are: 1. Determine seed protein concentrations and amino acid profiles (concentrations of nine essential amino acids) of seed protein of selected pea and chickpea cultivars and USDA breeding lines, and 2. Estimate the relative magnitude of genetic (G), environment (E) and G x E interaction effects on concentrations of individual amino acids and total protein in pea and chickpea seed.

Yield trials of green pea, yellow pea, and chickpea were established in Spring 2022 at several locations in Washington. For each market class (green pea, yellow pea, and chickpea) the same entries, including comparative check cultivars, were planted at each location. Each location is planted in a randomized complete block design (RCBD) with three replicated plots (1.2 x 6.1 m) per entry. All plots will be mechanically harvested, cleaned and weighed. After harvest, hundred seed weight (HSW) will be determined for each plot from a random 100 g sample. Concentrations of total protein and nine essential amino acids will be determined by the Cooperator using cleaned seed samples from each plot. The nine essential amino acids are phenylalanine, valine, tryptophan, threonine, isoleucine, methionine, histidine, leucine, and lysine. Seed protein concentrations will be determined using Fourier-transform infrared spectroscopy (FTIR). Concentrations of individual amino acids will be determined using an acid hydrolysis method with pre-oxidation step, followed by analysis using high performance liquid chromatography (HPLC). Analysis of variance (ANOVA) will be conducted across entries and locations, and years to estimate G, E, and G x E effects. Entry means will be compared using Tukey’s HSD test (a = 0.05). Pairwise correlations will be determined between seed protein concentration and concentrations of each essential amino acid, and also between these protein-associated variables and several agronomic traits including yield, seed size, and days to mature.