Relationships Among Antioxidant Activity, Total Phenolic Content and Specific Gravity in Several Potato (Solanum tuberosum L.) Cultivars Grown in Different Environments

摘要

Environmental conditions influence crop productivity and quality, making breeding for improvement of a particular trait challenging. Similarly, relationships among traits may make trait improvement difficult, especially if selection for high levels of one trait results in low levels of the other(s). Therefore, understanding the influence of environment and relationships among traits is necessary in trait selection and crop improvement. The objective of this study was to investigate the variability and correlations among antioxidant activity (AOA), total phenolic content (TP), and specific gravity (SPG) in potato cultivars and advanced breeding selections. This research included investigation of genotype x environment (GxE), using four cultivars (Atlantic, Red LaSoda, Russet Norkotah, and Yukon Gold) grown for 3 years (2005, 2006, and 2007) in nine states (CA, ID, MI, MN, NJ, NC, OR, TX, and WI), and two broader genotype studies using 15 advanced breeding selections grown in Texas in 2005 and 60 advanced selections and five cultivars grown in Texas in 2009. Two methods, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS), were used to evaluate AOA, and total phenolic (TP) content was determined using the Folin-Ciocalteau method. Significant effects of cultivar, year, location and their interactions on AOA, TP, and SPG were observed, as well as significant trait differences among cultivars within and between locations. The correlations between AOA and TP were significantly positive, while between AOA and SPG, and between TP and SPG were weak and negative in the GxE study. Correlations between AOA and SPG, and between TP and SPG in the two genotype studies were not significant. The weak relationships observed in the GxE study between AOA and SPG, and between TP and SPG may have been due to the small sample size and/or the cultivar Atlantic consistently exhibiting the lowest values of AOA and TP, and highest SPG in all locations. Results from the genotype studies suggest that breeding for high AOA and TP to increase the nutritional value of potato cultivars can be done without compromising tuber quality in terms of specific gravity.