Nitrogen Concentration Affects Nutrient and Carotenoid Accumulation in Parsley

ABSTRACT

Previous research has suggested that the herbal crop parsley (Petroselinum crispum Nym.) has a relatively high concentration of nutritionally important carotenoid phytonutrients, such as lutein-zeaxanthin and β -carotene. Nitrogen (N) has the most direct impact on plant growth, but influence of N on phytonutritional quality is contradictory. Therefore, the objectives of this study were to measure the effects of different concentrations of N on growth, elemental accumulation, and carotenoid production in parsley. ‘Dark Green Italian’ parsley was greenhouse-grown in a nutrient solution with 6.0, 13.1, 26.3, 52.5, or 105.0 mg N L⁻¹. After 8 weeks, plants were harvested and analyzed for biomass production, micro- and macronutrient concentrations, and lutein-zeaxanthin and β -carotene levels. Increasing N in the nutrient solution increased plant biomass, leaf tissue N, phosphorus (P), potassium (K), lutein-zeaxanthin, β -carotene, and chlorophyll. Leaf iron (Fe), manganese (Mn), and molybdenum (Mo) decreased with increases in N in nutrient solutions. Quadratic increases in response to increasing solution N occurred for leaf calcium (Ca), magnesium (Mg), sulfur (S), boron (B), copper (Cu), and zinc (Zn). Increasing the elemental and carotenoid concentrations in parsley through N fertility modification would be expected to increase the nutritional value of this culinary herbal crop.

Keywords:

• β -carotene
• chlorophyll
• human health
• lutein
• zeaxanthin
• macronutrient
• micronutrient

ACKNOWLEDGMENTS

This project was funded in part by an undergraduate student research award received by the Undergraduate Research Opportunities Program (UROP) at The University of New Hampshire. The manuscript partially fulfills the requirement for an honors senior thesis. This is Scientific Contribution Number 2206 from the New Hampshire Agricultural Experiment Station.

Notes

^a Mean composition of sampled leaf tissue of 4 replications, 10 plants each, ± standard error.

^b NS, ^*, ^**, ^*** not significant or significant at P ≤ 0.05, 0.01, or 0.001 level, respectively.

^a Mean composition of sampled leaf tissue of 4 replications, 10 plants each, ± standard error.

^b NS, ^*, ^**, ^*** not significant or significant at P ≤ 0.05, 0.01, or 0.001 level, respectively.

^a Mean composition of sampled leaf tissue of 4 replications, 10 plants each, ± standard error.

^b *** significant at P ≤ 0.001.