Natural variations and geographical distributions of seed carotenoids and chlorophylls in 1167 Chinese soybean accessions

Understanding the composition and contents of carotenoids in various soybean seed accessions is important for their nutritional assessment.This study investigated the variability in the concentrations of carotenoids and chlorophylls and revealed their associations with other nutritional quality traits in a genetically diverse set of Chinese soybean accessions comprised of cultivars and landraces.Genotype,planting year,accession type,seed cotyledon color,and ecoregion of origin significantly influenced the accumulation of carotenoids and chlorophylls.The mean total carotenoid content was in the range of 8.15–14.72μg g–1 across the ecoregions.The total carotenoid content was 1.2-fold higher in the landraces than in the cultivars.Soybeans with green cotyledons had higher contents of carotenoids and chlorophylls than those with yellow cotyledons.Remarkably,lutein was the most abundant carotenoid in all the germplasms,ranging from 1.35–37.44μg g–1.Carotenoids and chlorophylls showed significant correlations with other quality traits,which will help to set breeding strategies for enhancing soybean carotenoids without affecting the other components.Collectively,our results demonstrate that carotenoids are adequately accumulated in soybean seeds,however,they are strongly influenced by genetic factors,accession type,and germplasm origin.We identified novel germplasms with the highest total carotenoid contents across the various ecoregions of China that could serve as the genetic materials for soybean carotenoid breeding programs,and thereby as the raw materials for food sectors,pharmaceuticals,and the cosmetic industry.

Profiling seed soluble sugar compositions in 1164 Chinese soybean accessions from major growing ecoregions

Soluble sugar is a key quality trait of soybean seeds.We developed rapid and economic extraction and quantification methods for seed soluble sugars using an ultra-high performance liquid chromatography system with a refractive index detector.We evaluated the soluble sugar compositions of 1164 soybean accessions collected from diverse ecoregions and grown in multiple locations and years.Total soluble sugar(TSS)content was influenced by accession type,year of cultivation,and ecoregion.The mean contents of fructose,glucose,sucrose,raffinose,stachyose and TSS were 3.31,5.21,55.60,6.60,35.47,and 106.19 mg g^(-1),respectively.The highest mean TSS content(108.71 mg g^(-1)) was observed in accessions from Northern Region of China.Cultivars contained higher contents of sucrose,raffinose,and TSS,whereas landraces had a higher content of stachyose.Fourteen accessions with mean TSS contents>130 mg g^(-1) were identified as elite soybean resources.TSS was correlated with sucrose,raffinose,stachyose,protein,oil and total tocopherol.The main soluble sugar components were correlated with latitude and longitude,indicating that the geographical origin of the accessions affected their seed soluble sugar compositions.The developed methods and elite identified accessions can be used in the food and feed industry and in soybean breeding programs aimed at improving soybean seed nutrition.