Allelopathic activity of leaves, stalks and roots of Cymbopogon nardus

Abstract

In this study, leaves, stalks and roots of Cymbopogon nardus were separately evaluated to determine the most active parts that contained the strong growth inhibitory activity. Each aqueous methanol extracts of Cymbopogon nardus were determined their allelopathic activity by using six test plant species; alfalfa (Medicago sativa L.), cress (Lepidum sativum L.), lettuce (Lactuca sativa L.), barnyard grass (Echinochloa crus-galli L.), Italian ryegrass (Lolium moltiflorum Lam.) and jungle rice (Echinochloa colonum (L.) P. Beauv.). Four extract concentrations (0.01, 0.03, 0.1 and 0.3 g dry weight equivalent extract/mL) were used for the bioassay. The results showed that these three extracts have inhibitory activity and the percent inhibition increased concentration dependently. However, the inhibitory activity of leaf and root extracts was more effective than stalk extract at 95% level of significance. Barnyard grass, Italian ryegrass and jungle rice were the most sensitive to the leaf, stalk and root extracts, respectively. The concentrations required for 50% growth inhibition of C. nardus leaf, stalk and root extracts on all test plants were 0.000-0.025, 0.009-0.077 and 0.003-0.023 g dry weight equivalent extract/mL, respectively. In addition, separation of these extracts through silica gel column indicated that root extract contained the most active fractions with strong growth inhibition. The present results suggest that C. nardus may have allelopathic compounds and the root extracts have the greatest inhibitory activity. Studies are in progress for the isolation and identification of allelopathic compounds in aqueous methanol extracts of C. nardus roots for the development of natural herbicides.

Phytotoxic effects of Cerbera manghas L. leaf extracts on seedling elongation of four monocot and four dicot test species

“…Several studies by other researchers have also found that seedling elongation can be stimulated by allelochemicals at low concentrations and, conversely, that seedling elongation can be inhibited at high concentrations. A similar phenomenon was reported in case of extracts of Cymbopogon nardus [20], Leucas aspera [21], and Aglaia odorata [22]. Dose-response phenomenon characterized by a low dose stimulation and a high dose inhibition are known as hormetic responses.…”

“…The IC 50 (50% inhibitory concentration) value for each test species was obtained from logistic regression analysis. IC 50 values were calculated to determine the concentration required for 50% inhibition of seedling elongation [20].…”

Efficient Adventitious Morphogenesis from In vitro Cultures of the Medicinal Plant Cymbopogon schoenanthus

“…Roots extract from Cymbopogon citratus contained 10 sesquiterpenoid that differed in their chemical composition than those present in shoots (Li et al 2005). Cymbopogon nardus root extract contained the greatest inhibitory activity in comparing with leaf and stalk (Suwitchayanon et al 2014). The effect of vitamins in organ induction and developments were widely described in previous studies.…”

Profiles of Compounds in Stover of Rice, Cymbopogon, Desmodium, Mucuna and Maize

“…Poonpaiboonpipat et al (2013) reported that C. citratus essential oil damages the membrane system of barnyard grass (Echinochloa crus-galli L.), causing lipid peroxidation and electrolyte leakage. Barnyard grass, Italian ryegrass and jungle rice were reported as the most sensitive to the leaf, stalk and root extracts of C. nardus, respectively, by Suwitchayanon and Kato-Noguchi (2014). Krenchinsk et al (2017) reported that the aqueous extract from C. citratus by maceration decreased germination and germination rates of Bidens pilosa and Bidens subalternans more than the aqueous extract by infusion for both species.…”