GGE biplot analysis for seed protein concentration, yield, and seed size of chickpea cultivars and breeding lines in the U.S. Pacific Northwest

Authors: JOSHI, PRIYANKA - Clemson University; Vandemark, George

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Chickpea is produced throughout the U.S. Pacific Northwest and Northern Plains, where it is grown in rotations with small cereal grains including wheat and barley. The farm-gate value of chickpea produced in the U.S. exceeded $120 million in 2022. Typically, a substantially higher price is paid for larger seeds, which are bagged, canned, or served fresh, than smaller seeds, which are primarily used for making edible spread products such as hummus. Chickpea is an important source of plant-based protein to human diets across the world. However, malnutrition caused by inadequate dietary protein is prevalent in regions where chickpea has historically served as a major food crop. Increasing protein content in chickpea seeds has been proposed to be the most important research area in chickpea breeding. The most successful crop varieties typically have stable performance across different locations and years. The objectives of this research were to evaluate seed protein concentration, yield, and one hundred seed weight (HSW) of USDA chickpea breeding lines and varieties, determine relationships between protein concentration and several important field traits, and identify entries that stably have high protein concentration and high yield. We examined 17 kabuli chickpea entries planted in 2020 and 2021 at four locations in Washington: Colton, Pullman, Rosalia, and Walla Walla. The average seed protein concentration for all entries was 20.3%. Two breeding lines, CA0790B0429C, CA13900147C, and the variety ‘Sierra’, consistently had high seed protein concentration but low yield. The variety ‘Billy Beans’ was superior for yield. The variety ‘Nash’ and breeding line CA15940057C consistently had high hundred seed weight. No entry had high protein concentration, yield, and HSW. A positive correlation was observed between protein concentration and days to mature, suggesting higher protein is associated with late maturity, an undesirable trait. Our results suggest protein concentration should be evaluated in a larger and more diverse chickpea collection to identify high protein plant materials that can be used as parents and crossed with Billy Beans to develop new cultivars that stably express high seed protein concentration and yield.

Technical Abstract: Greater global demand for plant-based protein has made increasing protein concentration in chickpea (Cicer arietinum L.) an important breeding objective. In this study, 17 kabuli chickpea genotypes were evaluated for seed protein concentration, yield, and hundred seed weight (HSW). All entries were planted in 2020 and 2021 at four locations in Washington. The mean of all entries for seed protein concentration was 20.3%. Genotype (G), location (L), G x Year (Y), and L x Y (E) effects were significant for each trait. Year (Y) effects were significant for seed protein concentration and yield and accounted for the greatest percentage of total variance for both traits. GGE biplot analysis indicated G + G x E effects accounted for 78.69%, 64.01%, and 95.99% of the total variation for seed protein concentration, yield, and HSW, respectively. Environments tended to be positively correlated for all three traits and biplot analysis suggests three mega-environments. Three genotypes, CA0790B0429C, CA13900147C, and ‘Sierra’, consistently had high seed protein concentrations but were low yielding. ‘Billy Beans’ was superior for yield. ‘Nash’ was closest to an ideal genotype for high HSW. No genotype had high seed protein concentration, yield, and HSW. Significant positive correlations (r > 0.6) were observed between seed protein concentration, days to mature, and plant height. It will be challenging to make substantial gains in seed protein concentration using only the genotypes evaluated in this study.