Biopotentials of Marine Algae Extracts against Root-Knot Nematode, Meloidogyne incognita

Abstract

Nematicidal activity of four species of marine algae Ulva fasciata Delile (UF) (green algae), Corallina mediteranea, Corallina officinalis (red algae) and Spirulina platensis (blue-green algae) at concentrations of (125, 250, 500 and 1000 µg/ml) for aqueous and ethanolic extracts were investigated against the knot-root nematode, Meloidogyne incognita in laboratory and greenhouse on tomato plants. In laboratory experiments, all tested algae caused significant mortality of the second larval stage (J2). It was, also, noticed that the tested algae reduced egg hatching. Ethanol extract of all algae possesses highest nematicidal activity than water extract. U. fasciata, ethanolic extracts showed the highest nematicidal activity among the tested algae in vitro. The results of greenhouse experiment clarified that the tested ethanolic extracts of all algae, reduced numbers of root galls, egg masses and population of nematodes of tomato plants at concentration 1000 mg/kg soil compared to the inoculated control. U. fasciata was the most effective treatment in reducing root galls, egg masses and final population of the nematode except for oxamyl. Results revealed that all tested treatments increased various measures of plant growth characters; fresh shoot and root weights and lengths as well as reduced the root-knot infestation. Among all of the tested algae, U. fasciata followed by C. officinalis and C. mediteranea were the most effective treatments to increase both fresh shoot & root weights and lengths. None of the algae was phytotoxic at the tested treatments. A chemical constituent of U. fasciata was recognized by GC-MS. GC-MS analysis, exhibited the presence of organic component such as bis(2-ethylhexyl) phthalate which ranked the first with 63.75%, followed by diethyl phthalate (18.46%). Results stated that marine algae and especially, U. fasciata exhibited significant nematicidal activity in-vitro and in-vivo experiments and could be considered as useful natural namaticidal agents.

Nematicidal activity of seaweed-synthesized silver nanoparticles and extracts against Meloidogyne incognita on tomato plants

“…However, lipid-soluble extracts of marine macroalgae extensively researched as a potential source of novel pharmacological compounds. Several organic solvents were used to screen algal compounds for antibacterial and nematicidal activity 35 , 37 , 61 , 68 . Methylene chloride was used in this study to extract bioactive compounds from two tested macroalgal species, with C. sinuosa algal extract having higher anti-nematode activity against M. incognita than C. mediterranea .…”

“…El-Deen et al 35 used GC–MS to analyze the algal ethanolic extract of Ulva fasciata as a promising nematicide, which revealed the presence of organic component such as bis (2-ethylhexyl) phthalate at 63.75% and diethyl phthalate at 18.46%. Khan et al 37 investigated the biochemical potential of seaweed in two different solvents viz., water and methanol at ratios of 2.5, 5 and 10%. After 72 h, methanol extract (10%) of Colpomenia sinuosa recorded 82 ± 2.84% egg hatching and 91 ± 1.76% larval mortality.…”

“…It boosted the use of green silver nanoparticles as a novel method of controlling root knot nematodes 35 , 36 . According to Khan et al 37 various seaweeds have significant nematicidal activities such as inhibiting egg hatching, increasing larval mortality, and reducing root-knot disease. Furthermore, nanoparticles (NPs) have distinct physicochemical properties and the potential to improve plant metabolism 38 .…”

Marine Organisms for the Sustainable Management of Plant Parasitic Nematodes

“…Soil drench treatments (1 mg/mL) with ethanolic extracts of the green alga U. fasciata Delile and the red algae C. officinalis and C. mediterranea significantly reduced M. incognita infestation on tomato plants, though the extract of U. fasciata was much more effective (a 77.5% reduction in gall number/root) than the C. officinalis and C. mediterranea extracts, with a 50.3 and 34.7% reduction, respectively [ 38 , 51 ].…”