Characterization of two peanut genotypes for biochemical quality attributes and cotyledon microstructure features

Abstract Peanut is a world-renowned oilseed and food crop. Improving its biochemical quality traits is of great significance not only for meeting edible oil and food needs, but also for producing clean renewable energy. Identification of peanut genotypes with high and stable oil content in coastal areas is of economic importance, as the high oil trait of peanut bred in inland areas are difficult to fully express in coastal areas. Two peanut genotypes were grown at two sites in the coastal area. One of the genotypes was identified as with high oil and low carbohydrate, while the other, low oil and high carbohydrate. We noticed that number and total area of oil bodies were higher in high oil peanut than in low oil peanut, and that peanut with higher protein content had larger total protein body area. A novel finding of the present study was that number and area of starch grains were higher in peanut with high total soluble sugar (TSS) and sucrose contents than in peanut with low TSS and sucrose. Regarding the ultrastructural properties associated with oil, protein and TSS/sucrose contents, significant and highly positive correlations were detected between total oil body area and number of oil bodies, between total protein area and maximum protein body area, and between total starch grain area and number of starch grains. This study laid the foundation for further exploration of the mechanisms shaping peanut seed biochemical quality through transcriptomic, metabolomic and hormonal analysis.