Nutrient Solution Concentration Affects Growth, Mineral Composition, Phenolic Acids, and Flavonoids in Leaves of Artichoke and Cardoon

Abstract

<jats:p>A greenhouse experiment was conducted in Summer and Fall 2011 at the experimental farm of Tuscia University, central Italy, to study the effect of nutrient solution concentration (4, 20, 36, 52, or 68 mequiv·L<jats:sup>−1</jats:sup>) on biomass production, mineral composition, and concentrations of the major polyphenols in ‘Romolo’ artichoke and ‘Bianco Avorio’ cardoon grown in a floating system. Leaf dry biomass, leaf number, and macroelement concentrations (nitrogen, potassium, calcium, and magnesium) of artichoke and cardoon increased in response to an increase in the nutrient solution concentration, whereas an opposite trend was observed for the total polyphenols, phenolic acids (chlorogenic acid, cynarin, and caffeic acid), and the flavonoid luteolin. Artichoke and cardoon gave maximum biomass production and leaf number at 45 and 54 mequiv·L<jats:sup>−1</jats:sup>, respectively. Cardoon showed higher biomass and leaf number (average 1.13 kg·m<jats:sup>−2</jats:sup> and 14.0 n./plant, respectively) than those observed in artichoke (average 1.07 kg·m<jats:sup>−2</jats:sup> and 12.7 n./plant, respectively). The chlorogenic acid, cynarin, caffeic acid, and luteolin concentrations were higher by 204%, 462%, 580%, and 445% in cardoon leaf tissue than in that of artichoke. An improvement of leaf quality (total polyphenols, phenolic acids, and flavonoids) was obtained at the expense of leaf yield through the use of lower fertilizer concentrations in the nutrient solution.</jats:p>

Macronutrient deprivation eustress elicits differential secondary metabolites in red and green‐pigmented butterhead lettuce grown in a closed soilless system

“…scolymus (L.) Hegi) leaves, where K concentration decreased at the lowest two NS concentrations (2 and 20 mequiv L −1 ). However, trends that were not consistent with ours, with respect to Ca and Mg, were recorded in the works of both Rouphael et al . and Fallovo et al .…”

“…As expected, anthocyanins were detected only in red Salanova, where their concentration increased by 380.7% and 336.5% under moderate and severe nutrient stress conditions, respectively (Table ). These findings are in agreement with Rouphael et al ., who established that phenolic acids and flavonoids concentration varies as a function of nutrient stress and genotype. Gershenzon also reported that anthocyanins in Lactuca sativa L. were positively influenced by N deficiency, and Akula and Ravishanka attributed anthocyanin accumulation to nutrient deficiency in general.…”

“…The current results on phenolics corroborate those of Rouphael et al ., who found that a marked increase in phenolic compounds (specifically chlorogenic acid) and flavonoids was elicited by low‐concentration solutions (4 and 20 mequiv. L −1 ).…”

“…at EC = 0.3 dS m −1 (i.e., 2 meq L −1 ) were compatible with our results, which showed that P and K concentration decreased significantly at quarter‐strength NS (EC = 0.5 dS m −1 ). Similar results were obtained by Rouphael et al . on cardoon ( Cynara cardunculus L. var.…”

Effects of alternative cropping systems on globe artichoke qualitative traits

“…Furthermore, Orsini et al . reviewed that an inverse relationships exists between the nitrogen availability and phenolic accumulations in different vegetables and Rouphael et al . found that leaf total polyphenols, phenolic acids (chlorogenic acid, cynarin, and caffeic acid), and the flavonoid luteolin concentrations of artichoke decreased in response to an increase in the nutrient solution concentration.…”