Abstract
We aimed to investigate growth-promoting effect of Dermatocarpon miniatum and Parmelia saxatilis lichens on Ceratophyllum demersum propagated in vitro. Furthermore, we revealed antioxidant capacity variation in lichen-treated plant (allelopathic plant). C. demersum was subjected to methanol and water extracts from lichens, specifically D. miniatum and P. saxatilis. The most positive growth outcomes were witnessed when C. demersum was subjected to a methanol extract derived from P. saxatilis. We further examined DPPH scavenging and metal chelating activities, as well as total phenol and flavonoid contents, of the most robust allelopathic plants compared to control plants. Based on IC50 values, allelopathic plants exhibited greater efficacy in terms of DPPH scavenging and metal chelation activities in comparison with control. When we analyzed total phenols and flavonoids, both allelopathic plant samples, treated with both extracts, exhibited significantly higher levels (p < 0.05) compared to control. Methanol extract from allelopathic sample had maximum total phenol content (73.93 µg gallic acid equivalent/mg extract) and flavonoid content (66.26 µg quercetin equivalent/mg extract). In conclusion, this study will provide valuable input for future investigation in domain of plant development control and augmentation of biologically active substance propagation in plants, with a particular focus on utilizing P. saxatilis lichen.