Allelopathic Effect of the Invasive Ludwigia hexapetala on Growth of Three Macrophyte Species

Abstract

The release of allelochemicals by plants can affect the performance of other organisms positively or negatively. We tested the effects of aqueous extracts and leachates derived from the leaves and roots of the invasive water primrose (Ludwigia hexapetala) on one submerged native species – Ceratophyllum demersum, and two exotic species – the submerged Egeria densa and the emergent growth form of Myriophyllum aquaticum. The effect of the aqueous extracts and leachates of L. hexapetala on photosynthetic yield, growth (i.e., relative growth rate, leaf area), root length, and length of the lateral shoots of each species were analyzed in spring and in autumn. In autumn, an allelopathic effect was established on the traits of the three macrophytes species. The root extracts stimulated leaf area and the photosynthetic yield of C. demersum and of E. densa, whereas leaf treatments (leachates and extracts) and root leachate reduced the leaf area of M. aquaticum. The autumnal root leachate of L. hexapetala decreased the relative growth rate of C. demersum, whereas it had no effect on the two others plants. The root extract increased the length of lateral branches of M. aquaticum in autumn, suggesting a positive effect of L. hexapetala on the lateral growth of M. aquaticum. Three main allelochemicals were identified in leaves: quercitrin, prunin, myricitrin. The concentrations of these allelochemicals were greater in the leaf extract taken from L. hexapetala in autumn than in spring, and those found in the leaf leachates for both seasons. This assessment of autumnal allelopathy could help to explain the patterns of plant community succession in invaded areas.

Phytochemical profile, cytotoxic, antioxidant, and allelopathic potentials of aqueous leaf extracts of Olea europaea

“…The impact of allelopathy on composition and the structure of biological communities is relatively uninvestigated in olive extracts (Thiébaut, Thouvenot, & Rodríguez‐Pérez, 2018). Thus, the aim of this study is to assess whether the aqueous leaf extracts (infusion) of the O. europaea had an allelopathic effect on seed germination of T aestivum and Linum usitatissimum .…”

“…The inhibitory potential of allelopathy is complex, and different groups of chemicals can be involved such as phenolic compounds, terpenoids, flavonoids, alkaloids, amino acids, steroids, and carbohydrates (Al‐Samarai et al., 2018). It can be due to the congenital effects of plant containment in soluble substances in water and to biotic and the fluctuations of abiotic parameters, such as climatic conditions (Petrussa et al., 2013), the presence of herbivores and/or pathogens (Gatti et al., 2014; Silva, Overbeck, & Soares, 2014) and stage in the life history of the plant (Lombardo, Mjelde, Källqvist, & Brettum, 2013; Santonja, Le Rouzic, & Thiébaut, 2018; Thiébaut et al., 2018). In recent data, it was reported that the inhibitory activity may be attributed to the accumulation of glucosinolate in the plant parts, especially the leaves (Al‐Samarai et al., 2018).…”

Aqueous extract from leaves of Ludwigia hyssopifolia (G. Don) Exell as potential bioherbicide

“…Leaf extracts of other members of Ludwigia genus such as L. decurrens and L. adscendens are known to contain tannins, triterpenes, flavonoids, polyphenols, fatty acids, alkaloids and saponins, but not alkaloids . Since phenolics are the compounds more frequently involved in freshwater systems where L. hyssopifolia is commonly found, the study focused more on its phenolics . Phenolics are often encountered in freshwater systems due to their inherent higher water solubility compared to other phytochemical groups .…”

Allelopathic Effects of Native Versus Invasive Plants on One Major Invader

“…The ability of both Ludwigia spp. to release allelochemicals by roots into the soil may increase nutrient availability (Bardon et al, 2017; Thiébaut et al, 2018) and consequently stimulate the branching of L. hexapetala . More specifically, the lateral growth (number and length of lateral branches) and the total biomass of L. hexapetala were enhanced in the presence of the root leachate of L. peploides .…”

“…In a previous study, we established that L. hexapatala stimulated its own germination and could promote its own population persistence (Santonja et al, 2018). L. hexapetala produces allelochemicals (Dandelot et al, 2008; Santonja et al, 2018; Thiébaut et al, 2018) and these substances could be implicated in the outcome of the interactions between the water primrose and the surrounding species, be they native or exotic.…”