Calcium and magnesium biofortification of the edible cactus Nopalea cochenillifera grown under hydroponic conditions

In this study, we investigated the effect of calcium (Ca) and magnesium (Mg) supplementation on the growth of the edible cactus Nopalea cochenillifera (L.) Salm-Dyckand, by exposing hydroponically grown cladodes of N. cochenillifera to 0, 500, or 2000 mg L^‑1 of Ca or Mg for 14 weeks.
Daughter cladodes emerged from the mother cladodes and continued to grow at all three Ca and Mg concentrations tested.
However, growth of the daughter cladodes was inhibited and the fresh weights of both the daughter and mother cladodes were lower with the 2000 mg L^‑1 Ca treatment, 500 and 2000 mg L^‑1 Mg treatments.
High Ca and Mg concentrations in the nutrient solution greatly increased their concentrations in the plant parts.
For example, Ca and Mg concentration (μg g DW^‑1) in daughter cladodes (edible parts as fresh vegetables) treated with 2000 mg L^‑1 Ca and Mg increased around 32 and 23% compared with control, respectively.
Mg concentration (μg g DW^‑1) in mother cladodes treated with 2000 mg L^‑1 Mg increased around 40% compared with control, while there was no significant difference in Ca concentration in mother cladodes among different Ca treatment.
We also estimated that over 190 mg 100 g^‑1 fresh weight (FW) of Ca and over 100 mg 100 g^‑1 FW of Mg accumulated in daughter cladodes (edible parts). Thus, eating only 100 g of these cacti can satisfy about 20% of the daily Ca requirement, and about 40% of the daily Mg requirements.
These results suggest that Ca and Mg supplementation in the nutrient solution can cause mineral biofortification in edible cactus.

IV Asian Horticultural Congress – AHC2023

E. Nishimura, K. Hayashi, T. Horibe

Ca, Mg, cladodes, heavy metal, hydroponics, Opuntia, phytoremediation

https://doi.org/10.17660/ActaHortic.2024.1404.199