Genotype and environment effects on prebiotic carbohydrate concentrations in kabuli chickpea cultivars and breeding lines grown in the U.S. Pacific Northwest

Authors: Vandemark, George; THAVARAJAH, SAMHADHI - Clemson University; SIVA, NIROSHAN - Clemson University; THAVARAJAH, DIL - Clemson University

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/24/2020
Publication Date: 2/21/2020
Citation: Vandemark, G.J., Thavarajah, S., Siva, N., Thavarajah, D. 2020. Genotype and environment effects on prebiotic carbohydrate concentrations in kabuli chickpea cultivars and breeding lines grown in the U.S. Pacific Northwest. Frontiers in Plant Science. 11:112. https://doi.org/10.3389/fpls.2020.00112.
DOI: https://doi.org/10.3389/fpls.2020.00112

Interpretive Summary: Prebiotic carbohydrates are compounds that include sugars, such as sucrose and glucose, and other compounds derived from sugars, such as mannitol and starches. These compounds are used as food sources by bacteria that live in our intestinal tract and are associated with several health benefits including reduced obesity and insulin dependence and protection against development of colorectal cancer. Although chickpeas have served as important sources of nutrition for human diets for thousands of years, relatively little is known about the profiles of prebiotic carbohydrates in chickpea seeds. The objectives of this study were to characterize the type and concentration of seed prebiotic carbohydrates in 24 different chickpea lines grown in Idaho and Washington, and determine the relative importance of genetic and environmental factors on thse traits. Genetic factors were especially important for sucrose concentration, suggesting this trait could be easily improved through plant breeding. However, for other prebiotic carbohydrates, environmental factors were more important than genetic factors. Overall, our results suggest that we need to examine more genetically different chickpea lines to identify lines that produce significantly greater concentrations of selected prebiotic carbohydrates and could be used to introduce desirable nutritional traits into adapted chickpea cultivars.

Technical Abstract: Prebiotic carbohydrates are compounds that include simple sugars, sugar alcohols, and raffinose family oligosaccharides, which are fermented by gut bacteria and can influence the species profile of the gut microbiome to reduce obesity and weight gain. Fermentation of prebiotic carbohydrates produces short chain fatty acids that are associated with several health benefits including reduced obesity and insulin dependence and protection against development of colorectal cancer. Although pulse crops such as chickpea have served as important sources of nutrition for human diets for thousands of years, relatively little is known about the profiles of prebiotic carbohydrates in seeds of pulse crops. The objectives of this study were to characterize the type and concentration of seed prebiotic carbohydrates in 24 kabuli genotypes grown in Idaho and Washington, and partition variance components conditioning these nutritional quality traits in chickpea. Significant genetic effects were detected for concentrations of several prebiotic carbohydrates, including mannitol, sucrose, and raffinose. Genetic effects explained the majority of total variance for sucrose concentration, suggesting this trait could be improved using adapted materials as parents. However, for other prebiotic carbohydrates genetic effects were either not significant or were of less magnitude than environmental effects. Genotype x environment interaction effects were not significant for any prebiotic carbohydrates. Overall, our results suggest that a survey of more genetically diverse plant materials, such as a chickpea ‘mini-core’ collection, may reveal genotypes that produce significantly greater concentrations of selected prebiotic carbohydrates and could be used to introduce desirable nutritional traits into adapted chickpea cultivars.