Altitudinal variability in chemical profile and pesticidal properties of Zingiber roseum (Roxb.) Roscoe extracts

Abstract

Plant extracts are considered as a promising alternative to chemical pest control agents. The chemistry of plant extracts varies with several environmental as well as geographical factors. Zingiber roseum (Roxb.) Roscoe also known as “Rosy Ginger” and “Jangli Adrak” is one of the most important aromatic and medicinal plant of family Zingiberaceae. The present study aimed to investigate the impact of altitude on the chemical composition, nematicidal and herbicidal activity of Z. roseum rhizome and seed extracts. The plants were collected from three different altitudes of Kumaun, Uttarakhand representing different environmental conditions. The extracts were prepared in acetone using cold percolation method. The compositional variation in chemical constituents of the extracts was determined by gas chromatography-mass spectrometry (GC–MS) analysis. The yield and chemical composition of extracts showed a significant altitudinal impact. Nematicidal activity of extracts was performed against Meloidogyneincognita. Results showed that the extracts exhibited significant nematode mortality irrespective of the altitudinal gradients. A significant correlation of altitudinal gradient was observed for the nematode egg hatchability reduction for the rhizome extracts. It was observed that plants growing at higher altitudes had better egg hatchability reduction (86.42 ± 2.30% at 1000 μg/mL after 96 h), compared with those growing at lower elevations. The herbicidal activity of rhizome and seed extracts was performed against radish and chicory seeds and the extracts showed different level of intensity of germination percentage, root and shoot length inhibition. In silico molecular docking was conducted to screen the nematicidal activity of major and potent compounds with the crystalline structure of Glutathione S-transferases (GSTs) of Caenorhabditis elegans and Wuchereria bancrofti, and Glutathione S-transferase-1 (GST-1) of M. incognita. Based on the current study, extract of Z. roseum may be regarded as potential nematicidal and herbicidal agents and may have potential application as botanicals.