Investigations into genotypic variations of peanut carbohydrates

Carbohydrates are known to be important precursors in the development of ro asted peanut quality. However, little is known about their genotypic variat ion. A better understanding of the role of carbohydrates in roasted peanut quality requires first an understanding of the genotypic variation in the s oluble carbohydrate components. Ion exchange chromatography was used to iso late 20 different carbohydrate components in 52 genotypes grown in replicat ed trials at two locations. Inositol, glucose, fructose, sucrose, raffinose , and stachyose were quantitated, and 12 unknown peaks were evaluated on th e basis of the peak height of the unknown relative to the cellobiose intern al standard peak height. Peaks tentatively identified as verbascose and aju gose could not be properly integrated because of tailing. Of the 18 carbohy drates that were estimated, 9 exhibited significant variation between test environments, 5 among market types, 14 among genotypes within market types, and 11 exhibited some significant form of genotype x environment interacti on. Genotypes accounted for 38-78% of the total variation for the known com ponents, suggesting that broad-sense heritability for these components is h igh. The observed high genotypic variation in carbohydrate components is si milar to the high genotypic variation observed for the sweetness attribute in roasted peanuts, which raises the question regarding possible interrelat ionships. The establishment of such interrelationships could be most benefi cial to peanut breeding programs to ensure the maintenance of flavor qualit y in future peanut varieties.