Plant growth regulator-mediated vitamin biofortification of indigenous leafy vegetable microgreens: A sustainable strategy for nutritional security

The lack of micronutrients, also known as hidden hunger, remains a major challenge to nutrition security globally and microgreens are fast-growing and nutrient-rich, thus providing a viable pathway for biofortification. The effect of gibberellic acid (GA3) and naphthalene acetic acid (NAA) on the vitamin enrichment of five indigenous leafy vegetable microgreens of Chhattisgarh grown under protected cultivation over two years was studied. The data collected from the 4 treatments and 4 replications for each crop were analysed using a completely randomised design (CRD) and based on the results of the 2 years of data, the application of plant growth regulators generally increased the levels of vitamins A, C, E and K compared with the water spray/control treatment, with GA3 + NAA recording numerically higher values for several crops-vitamin combinations, although it was statistically at par with NAA alone in some cases. Red amaranth stood out as the best performer, reaching the highest vitamin A (8027.62 µg 100 g-1), vitamin C (52.23 mg 100 g-1), vitamin E (3.33 mg 100 g-1) and vitamin K (535.41 µg 100 g-1) under the combined GA3 + NAA treatment, increases of 4.14, 12.76, 8.12 and 3.01 % over the control respectively. The results suggest biofortification of indigenous microgreens using agronomic methods based on GA3 and NAA is possible and inexpensive and that red amaranth is one of the crops that could contribute to nutritional security through vitamin fortification. These results support agronomic biofortification of indigenous microgreens as a low-cost, scalable strategy to increase dietary vitamin intake in resource-limited settings, while highlighting the need for further research on nutrient bioavailability and realistic consumption levels before firm dietary recommendations can be made.