Phytotoxic Activity and Identification of Phytotoxic Substances from Schumannianthus dichotomus

Abstract

The phytotoxic potential of plants and their constituents against other plants is being increasingly investigated as a possible alternative to synthetic herbicides to control weeds in crop fields. In this study, we explored the phytotoxicity and phytotoxic substances of Schumannianthus dichotomus, a perennial wetland shrub native to Bangladesh, India, and Myanmar. Leaf extracts of S. dichotomus exerted strong phytotoxicity against two dicot species, alfalfa and cress, and two monocot species, barnyard grass and Italian ryegrass. A bioassay-driven purification process yielded two phenolic derivatives, syringic acid and methyl syringate. Both constituents significantly inhibited the growth of cress and Italian ryegrass in a concentration-dependent manner. The concentrations required for 50% growth inhibition (I50 value) of the shoot and root growth of cress were 75.8 and 61.3 μM, respectively, for syringic acid, compared with 43.2 and 31.5 μM, respectively, for methyl syringate. Similarly, to suppress the shoot and root growth of Italian rye grass, a greater amount of syringic acid (I50 = 213.7 and 175.9 μM) was needed than methyl syringate (I50 = 140.4 to 130.8 μM). Methyl syringate showed higher phytotoxic potential than syringic acid, and cress showed higher sensitivity to both substances. This study is the first to report on the phytotoxic potential of S. dichotomus and to identify phytotoxic substances from this plant material.

Phytotoxic Activity and Growth Inhibitory Substances from Albizia richardiana (Voigt.) King & Prain

“…The I 50 values of the tested species were different, indicating that the inhibitory effects were test-plant specific ( Table 1). The concentration-dependent and test-species-dependent inhibitory effects of the leaf extract of Albizia richardiana indicate that this leaf extract might possess phytotoxic compounds, and this inhibitory activity has been reported in various studies [40][41][42][43].…”

Allelopathic Potential of Aqueous Extract from Acacia melanoxylon R. Br. on Lactuca sativa

“…Most of the polyphenols, identified in the present study ( Table 5 ) are assumed to be water soluble and, mostly, phenolics have good potential as templates for new herbicide classes [ 36 , 37 ]. Different polyphenols (phenolic compounds, flavonoids, derivatives of hydoxybenzoic acids, derivatives of cinnamic acids) were identified and seem to be water soluble; previously, it was elaborated that most of the allelochemicals, when in contact with plant cell walls, caused phytotoxicity and interfered in the ecophysiological parameters of the target plants [ 36 , 38 , 39 ]. These phytochemicals possess certain properties and can be used them as lead compounds for new herbicide discovery program [ 3 , 19 , 23 , 40 , 41 ].…”

Monoterpenes and Sesquiterpenes of Essential Oils from Psidium Species and Their Biological Properties

“…The phytotoxic potential of plants and their chemical constituents against invasive plants is increasingly investigated as a possible alternative to synthetic herbicides in crops weed control [ 114 ]. Some Psidium essential oils inhibited parasitic herbs’ growth, showing the potential to be used against the crops’ invasive plants [ 22 ].…”