Search

Copyright of Phytochemical Analysis is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Invasive alien species are major threats to biodiversity worldwide. Senna spectabilis is one such species that has been introduced to several countries, including India. This study aimed to investigate the allelopathic potential of aqueous extract of leaves of Senna spectabilis on native plants. For these five native plant seedlings (Ailanthus tryphysa (AT), Pongamia pinnata (PP), Tectona grandis, Hopea parviflora (HP), and Dendrocalamus strictus (DS)) of 6 months old were root fed with leaf extract of S. spectabilis for 3 years. Assays such as metabolic activity, L-proline estimation, lipid peroxidation and antioxidant enzymes (Superoxide dismutase, Catalase, Ascorbate peroxidase and Polyphenol oxidase) were used to assess the allelopathic potential of S. spectabilis, and finally, bioactive phytochemical compounds like Neophytadiene, Nerolidol, 2,4-Ditert-Butylphenol etc. were identified by gas chromatography coupled with mass spectrometry (GC–MS). The effects of S. spectabilis extracts highly varied depending on the native species and the variable measured. Regarding antioxidant enzyme activities of the native species, APX and CAT were generally higher in AT and HP, independently of the treatment with S. spectabilis extracts. However, SOD of AT and PP clearly increased as the concentration of the S. spectabilis extracts increased. In general, S. spectabilis extracts tend to increase formazan content of HP and DS and proline content of PP. GC‒MS analysis detected 28 phytoconstituents in the S. spectabilis leaf extracts and 7 plant allelochemicals were identified, including phenolic compounds, fatty acids, and terpenoids. These findings suggest that S. spectabilis has strong allelopathic potential, which could contribute to its invasive potential. The present study highlights the need for effective management strategies to control the spread of this invasive species and the importance of selecting specific native species for restoration programs. [ABSTRACT FROM AUTHOR]

The exotic ornamental tree Senna spectabilis (DC.) H. S. Irwin and Barneby has invaded various Protected Areas of the Nilgiri Biosphere Reserve including the Wayanad Wildlife Sanctuary in India creating a significant threat to biodiversity. This study examined the allelopathic potential and heterotoxicity of invasive S. spectabilis leaf extract by bioassay under laboratory conditions and identified its allelochemicals using HRLC-ESI–MS (QTOF) analysis. The bioassay experiment with test plant species including Vigna radiata (mung bean), Cicer arietinum (chickpea), and Amaranthus cruentus (red amaranth) was conducted in the laboratory and the methanolic leaf extract found to exhibit the greatest inhibitory activity. The percentage of inhibition of plumule growth by methanolic leaf extract on V. radiata, C. arietinum, and A. cruentus were 82%, 86%, and 99%, respectively. Phenol and proline content were significantly increased in germinated seedlings treated with even a quarter strength of leaf extract. Further by HR-LCMS analysis fifteen important allelochemicals were identified including phenolic compounds, flavonoids, anthraquinone, benzoic acid derivatives, and cinnamic acids. A soil sterilization experiment was used to examine the role of soil microbes in the phytotoxicity of leaf leachate. No significant variations exhibited in the phytotoxicity. The full strength of leaf leachate inhibited the shoot length of B. bambos by 52% in the sterile and 48% in the non-sterile soil, whereas it was 74 and 68%, respectively, in V. radiata. Further studies in the process of allelochemical release and their mode of action may confer a more lucid knowledge concerning the invasion mechanisms of S. spectabilis through allelopathy, guiding to practical management strategy. [ABSTRACT FROM AUTHOR]