Allelochemicals change macromolecular content of some selected weeds

Abstract

Allelochemicals are eco-friendly and play a significant part in weed control. In this regard, an in-vitro investigation was performed to evaluate the phytotoxic potential of Nicotiana. plumbaginifolia Viv. on Senna sophera (L.) Roxb., Chenopodium album L., Senna tora (L.) Roxb. and Setaria viridis L. The experiment is aimed to assess the impact of leaf leachate of the allelopathic plant on the biochemical parameters (chlorophyll, carbohydrate, protein and proline content) of recipient weeds. The treatments showed a retarding effect on the biochemical events. Carbohydrate and proline content were increased in test plants whereas protein and chlorophyll content declined in comparison to the control. Aqueous leachates proved to be more suppressive than organic fractions on weeds viz; S. sophera and C. album were suppressed more as compared to S. tora and S. viridis. The GC–MS (gas chromatography–mass spectrophotometry) analysis showed the incidence of different phytochemical entities in the leaf methanolic extract of leaf of N. plumbaginifolia. Forty three compounds were identified representing 98.98% of total methanolic extract composition. The main chemical components were Palmitic acid (17.50%), Palmitoleic acid (14.32%), Oleic acid (13.83), Phytol (8.46%), Neophytadiene (5.47%) and Solasodine (4.23%). The allelopathy of the volatile allelochemicals may perform a vital part in inhibiting the competitive ability of weed species and be one of the alternatives to control weed infestation.