Title : Allelopathic and tissue anatomical effects of invasive Nigerian weeds on cultivated and weed species
Abstract:
Background: This study investigated the allelopathic and tissue anatomical effects of two invasive Nigerian weeds, C. odorata and T. diversifolia, on test plants, in order to identify the allelopathic principles, and search for new plant-based agrochemicals for sustainable ecosystem management and human health.
Method: The seed germination inhibitory effects of aqueous and organic extracts of different parts of C. odorata and T. diversifolia, on the seeds of three cultivated economic plants (Abelmoschus caillei, Trichosanthes cucumerina, and Corchorus olitorius) and two weed species (Megathyrsus maximus and Ageratum conyzoides) were investigated. The inhibitory effects on seedling growth was determined by a screen house assay. Effect of the extracts on the test plants was determined by tissue anatomic studies. Bioactivity-guided purification, isolation and characterisation of the active principles using NMR and GC-MS was also carried out.
Results and Conclusion: The result showed that T. diversifolia stem methanol extract and C. odorata leaf aqueous extract exhibited germination inhibitory effects on all test species. Additionally, T. diversifolia demonstrated seedling growth inhibitory activity, while C. odorata exhibited stimulatory effect on seedling growth. Microscopic analysis of the plant tissues treated with C. odorata extract revealed enhanced anatomical differences compared to untreated control samples, supporting its previously observed growth-stimulatory activity. The presence of cyclic terpenoid derivative and an acrylaldehyde moiety identified in the stem of T. diversifolia were responsible for the observed allelopathic activity. This research also reported the phytotoxicity of palmitic acid, a long chain fatty acid, in addition to the plant toxicity report of middle chain fatty acids in the literature.
Audience Take Away Notes:
- The findings from the study on the allelopathic effects of two successful exotic invaders on three economically important indigenous Nigerian crops and two weed species will be elaborated upon.
- Participants will gain knowledge on the preparation of extracts from the most potent plant component to be used as organic herbicides for weed control.
- Informative content will be presented concerning allelopathy and invasion, enhancing comprehension of the invasion's magnitude and enabling the effective management of its detrimental impacts on the ecosystem.
