Screening of Allelochemicals in Miscanthus sacchariflorus Extracts and Assessment of Their Effects on Germination and Seedling Growth of Common Weeds

Abstract

There is increasing interest in the application of bioherbicides because they are less destructive to the global ecosystem than synthetic herbicides. Research has focused on reducing the dependence upon synthetic herbicides by substituting them with environmentally and economically sustainable bioproducts. Allelopathic phytochemicals may be an efficient method for controlling weeds, benefitting both the environment and human health. This study addressed the allelopathic potential of Miscanthus sacchariflorus (MS) extracts on the germination, plant growth, biomass, and biochemical parameters (electrolyte leakage, photosynthetic pigments, and antioxidant enzyme activities) of weeds using laboratory and field experiments. Liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) showed the presence of 22 phenolic compounds, including Orientin, Luteolin, Veratric acid, Chlorogenic acid, Protocatechuic acid, p-Coumaric acid, and Ferulic acid. Leaf extracts of M. sacchariflorus either completely suppressed or partially reduced seed germination and affected the development of weed seedlings (root and shoot length), in a dose-dependent manner. Aqueous extracts of M. sacchariflorus reduced the fresh weight and dry weight, affected the photosynthetic pigment content (chlorophylls, carotenoids), influenced the electrolyte ion leakage, and stimulated the activity of antioxidant enzymes in a species-specific manner. Pearson’s correlation analysis showed that the phenolic compound composition of M. sacchariflorus correlated with the variables tested, indicating that the phytochemicals present in the plant extracts of M. sacchariflorus are a potential source of bio-herbicides.

Weed pressure determines the chemical profile of wheat (Triticum aestivum L.) and its allelochemicals potential

“…Studies on different weed species have shown that allelochemicals toxicity leads to degradation of chlorophyll, decrease in starch accumulation, and interference in the size and number of chloroplasts. 42 A study conducted on broad leaf weed (Rumex acetosa) showed that at higher ferulic and p-hydroxybenzoic acids levels, photosynthetic machinery and photosystem II photochemistry were significantly decreased, compared to control. 43 Reduction in photosynthetic pigments and functions were also highly decreased in maize seedlings after treatment with Nicotiana plumbaginifolia Viv., as demonstrated by Singh et al 44 By targeting photosynthetic pigments and carotenoids (chlorophyll a, chlorophyll b, ⊎-carotene, lutein, neoxanthin, and violaxanthin) to identify allelochemicals stress responses in monocot and dicot weeds, we focused on different germination and seedling growth traits under the various planting densities.…”

Three Active Phytotoxic Compounds from the Leaves of Albizia richardiana (Voigt.) King and Prain for the Development of Bioherbicides to Control Weeds

“…Allelopathy reduces and disrupts the germination of crop seeds and restricts the growth of shoots and roots [ 21 ]. Most of the plant physiological mechanisms such as photosynthesis, functions of membranes and enzymes, water and nutrient uptake and germination of seedlings are influenced by allelochemicals [ 22 , 23 ]. Moreover, phytochemicals may be applied as bioherbicides to increase crop production by means of biological weed management through allelopathy.…”

Caffeic Acid, an Allelochemical in Artemisia argyi, Inhibits Weed Growth via Suppression of Mitogen-Activated Protein Kinase Signaling Pathway and the Biosynthesis of Gibberellin and Phytoalexin

“…In recent years, with the proliferation of weeds and the abuse of chemical herbicides, an increasing number of allelopathic plants have been found to inhibit the growth of harmful weeds. For instance, Ficus carica suppresses Peganum harmala and Silybum marianum ( Ladhari et al, 2020 ), allelopathic rice significantly inhibits E. crusgalli ( Li et al, 2020 ), and Miscanthus sacchariflorus can also suppress weed growth ( Ghimire et al, 2020 ). In our previous study, field observation and laboratory experiments have confirmed that A. argyi is an ecologically dominant population and can also be used for weed control.…”

“…Additionally, an increasing number of studies have examined the application of allelochemicals in plants to effectively control weed growth in recent years ( Iqbal et al, 2016 ; Ladhari et al, 2018 ). These plant-derived allelochemicals have been widely studied because of their advantages of environmental friendliness, low toxicity, easy degradation and lack of residue ( Ghimire et al, 2020 ). Thus, it is of great significance to clarify the allelochemicals secreted by A. argyi and their molecular mechanism for elucidating its ecological advantages and regulating the ecological balance.…”