Document Type : Research Paper
Authors
1 PhD student, Department of Horticultural Science and Engineering, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz
2 Associate Professor, Department of Horticultural Science and Engineering, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz
3 PhD, Department of Horticultural Science and Engineering, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz
Abstract
Introduction
Basil microgreen (Ocimum basilicum L.) is a valuable plant belonging to the Lamiaceae family, which is known as a superfood in the 21st century due to its high antioxidant index, including phenolic compounds, flavonoids, and carotenoids. In addition to their antioxidant and nutritional properties, microgreens are introduced as one of the strategic products that can be produced in vegetable production factories due to their short growth period, compatibility with soilless cultivation systems, ability to be cultivated in layered cultivation systems and high profitability. However, there are several challenges facing vegetable producers that hinder the development of microgreen cultivation. One of the most important production parameters is light intensity, the results of which are limited on the performance and synthesis of basil microgreen secondary metabolites in past research.
Materials and Methods
This research was conducted in the Department of Horticultural Science, Faculty of Agriculture, Shahid Chamran University of Ahvaz, in February 2024. This experiment aims to investigate the effect of different intensities of red+blue continuous LED light with a ratio (1:1) including 18 (82.8 µmol m-2 s-1), 36 (165.6 µmol m-2 s-1), 54 (248.4 µmol m-2 s-1) and 72 (331.2 µmol m-2 s-1) Wm-2s-1 on the yield and synthesis of secondary metabolites of three cultivars (Kapoor, Red Rubin, Violetta) and one genotype (Abloq) of basil microgreen were investigated using a split-plot approach based on a randomized complete block design in a floating system with four replications.
Results and Discussion
The results showed that the simple effect of light intensity on all studied traits had a significant difference at the 1% level. Also, the simple effect of cultivar and the interaction between light intensity and cultivar on all studied traits created a significant difference. The highest and lowest yield were obtained in Red Rubin cultivar (4.1 kg m-2) with light intensity of 331.2 µmol m-2 s-1 and in Violetta cultivar (0.5 kg m-2) with light intensity of 82.8 µmol m-2 s-1, respectively. The highest antioxidant capacity (78.31%), anthocyanin (31.0 mg 100 g-1 of fresh weight), vitamin C (306.1 mg 100 g-1 of fresh weight) and phenolic compounds (2039.6 mg 100 g-1 of fresh weight) were measured in Ablaq genotype under light intensity of 331.2 µmol m-2 s-1. The highest amount of proline was measured in Red Rubin cultivar (3.61 mg g-1 fresh weight) grown under a light intensity of 331.2 µmol m-2 s-1 and the lowest amount of proline was measured in Ablaq genotype (1.55 mg g-1 fresh weight) under light intensity of 82.8 µmol m-2 s-1. The highest amount of flavonoids was measured in Violetta cultivar (8.42 mg g-1 fresh weight) under light intensity of 331.2 µmol m-2 s-1 and the lowest amount of flavonoids was measured in Red Rubin cultivar (3.45 mg g-1 fresh weight) under light intensity of 82.8 µmol m-2 s-1. Basil microgreen performance with antioxidant capacity, anthocyanin, carbohydrate, proline, vitamin C, total phenolic compounds, and flavonoids had a positive and significant correlation at the 1% level.
Conclusion
The light intensity of red+blue LED lamps affected the synthesis of secondary metabolites and the yield of basil microgreens. Based on the results of the Ablaq genotype under the light intensity of 331.2 µmol m-2 s-1, it can be used as a suitable method for growing basil microgreens in the floating system.
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