Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 2/27/2010
Publication Date: 10/31/2011
Citation: Scagel, C.F., Lee, J. 2011. Phenolic composition of basil plants is differentially altered by plant nutrient status and inoculation with mycorrhizal fungi. HortScience. 46:S240-S241.
Technical Abstract: Quality of basil plants (Ocimum basilicum) used in certain fresh and dry products is a function of its production of secondary metabolites, including phenolic compounds. Nutrient availability, particularly phosphorus (P), can alter plant production of secondary metabolites, and root infection by arbuscular mycorrhizal fungi (AMF) may also alter production of phenolic compounds. The objectives of this study were to assess (1) whether P-availability and inoculation with AMF influence the phenolic composition of basil plants; and (2) how phenolic composition is related to plant nutrient status. Four cultivars of basil were inoculated or not with AMF and grown in a soilless substrate with two different rates of P. Fourteen-week-old plants were assessed for growth, AMF colonization, and analyzed for anthocyanins, total phenolics, specific polyphenolics, and mineral nutrients. In general, increased P-rate and AMF inoculation increased fresh and dry biomass. AMF colonization of inoculated plants was not influenced by P-rate. Across all cultivars, increased P-rate enhanced uptake (concentration and content) of P and Ca. Inoculation with AMF enhanced uptake of N, K, S, Mg, and B in low-P plants and enhanced uptake of S, B, and Zn in high-P plants. Rosmarinic acid was the predominant polyphenolic produced by all cultivars, and differences in rosmarinic acid content between treatments were a function of plant size. Increased P-rate and inoculation with AMF enhanced production (concentration and content) of several polyphenolics and resulted in treatments altering the phenolic composition in the whole plant and aboveground structures. Across all cultivars, P-rate and AMF inoculation only had a similar production enhancing effect on one phenolic compound – chicoric acid. Results indicate that fertilizer management can be used to alter phenolic composition of basil and that AMF inoculation may provide an additional strategy for optimizing basil quality beyond benefits obtained from just altering plant nutrient status.