An Insight into Ampelocissus latifolia as a Green Alternative to Chemical Herbicides with its Allelopathic and Cell Cycle Modulatory Activities

Abstract

Herbicides, used to kill unwanted plants in agricultural fields, usually function as branched chain amino acid inhibitors, growth regulators, root growth inhibitors, cell membrane disruptors, pigment synthesis inhibitors etc. Rampant use of chemical herbicides imposes serious environmental impact like biomagnification, having profound effect on human and animal health, causing side effects ranging from mild to deadly. Recently, the search for biological herbicides of plant origin is gaining renewed interest. The present study investigated the allelopathic and cell cycle modulatory effects of aerial parts' aqueous extract of Ampelocissus latifolia (AAEAL) on radicle growth inhibition and cyto-genotoxicity induction in some plants like wheat, onion, moong beans and also on the inhibition of budding and proliferation of the aquatic plant lesser duckweed fronds. Wheat seeds, onions, moong beans and lesser duckweeds were exposed to a wide range of concentrations (0.5-6 mg/mL) of AAEAL for different time periods (15 days for lesser duckweed bioassay and 2-96 h for other plants) for morphometric bioassays, study of morphological and cytological alterations, genotoxic stress induction and lesser duckweed frond budding bio-assays. After 24-96 h seedling lengths were measured. Cyto-genotoxic effect was analyzed on onion root apical meristem cells by scoring mitotic index and percentages of cellular and chromosomal aberration using light microscope. Ethidium bromide and acridine orange staining was done for fluorescence microscopic analysis of phytotoxicity. Results indicated that AAEAL inhibited (p<0.001) the growth of the seedlings in a concentration dependent manner, with concomitant decrease in mitotic index (p<0.001) and increased cyto-genotoxicity (p<0.001) in treated root tip cells. Interphase nuclear condensation, c-metaphase, vagrant chromosome, chromosomal bridge, sticky chromosome were the commonest types of aberrations found. Decrease in frond number and the increased number of dead fronds of AAEAL treated lesser duckweeds also suggested allelopathic potential of the extract. Thus allelochemicals from A. latifolia possess a strong inhibitory activity against other plant species (both terrestrial and aquatic), directing its good future prospect for the formulation of cost effective and ecofriendly herbicidal agents.