Biocontrol methods alternative to synthetic pesticides are a priority for both organic and conventional farming systems. Different classes of plant-specialized metabolites, including saponins, polyphenols and tannins, have been shown to possess potential as biocontrol agents. Recently, our group investigated the antifungal and nematocidal activity of specialized metabolites extracted from Medicago spp., oat (Avena sativa), and sulla (Hedysarum coronarium). Saponins, consisting of a triterpene or steroid aglycone with one or more sugar chains, were assayed against Verticillium dahliae Kleb., a widely distributed fungal phytopathogen that causes vascular wilt disease. The triterpene saponins extracted from M. sativa (mainly containing medicagenic acid glycosides) reduced fungal growth by up to 59% (1% concentration, 12 days), while, oat seed saponins, a mixture of triterpenoid and steroidal type, showed an inhibition of fungal growth of 66% (4% concentration, 12 days). In addition, these specialized phytochemicals were not phytotoxic at the antifungal concentrations confirming their potential suitability for horticultural crop protection. Saponins obtained from different Medicago species proved to be strongly active on the phytoparasitic nematodes Xiphinema index, Meloidogyne incognita, and Globodera rostochiensis and generally resulted in mortality rates not significantly different from those of the synthetic nematicide oxamyl. Flavonoids (mainly represented by kaempferol and quercetin rutinosides) and tannins (predominantly of the prodelphinidin type) extracted from sulla proved to be toxic towards the infective juveniles of the root-knot nematode M. incognita, causing a mortality greater than 89% (250 mg mL-1 concentration, 96 hours), similar to that obtained with the chemical treatment with fluopyram [2]. The in vitro nematotoxic activity was also confirmed by using Medicago or sulla biomasses, as soil organic amendments. Both biomasses significantly suppressed M. incognita multiplication and gall formation on tomato roots, as well as nematode infestation in the soil.
Potential of Plant Specialized Metabolites for Crop Protection
D'Addabbo T;
2023
Abstract
Biocontrol methods alternative to synthetic pesticides are a priority for both organic and conventional farming systems. Different classes of plant-specialized metabolites, including saponins, polyphenols and tannins, have been shown to possess potential as biocontrol agents. Recently, our group investigated the antifungal and nematocidal activity of specialized metabolites extracted from Medicago spp., oat (Avena sativa), and sulla (Hedysarum coronarium). Saponins, consisting of a triterpene or steroid aglycone with one or more sugar chains, were assayed against Verticillium dahliae Kleb., a widely distributed fungal phytopathogen that causes vascular wilt disease. The triterpene saponins extracted from M. sativa (mainly containing medicagenic acid glycosides) reduced fungal growth by up to 59% (1% concentration, 12 days), while, oat seed saponins, a mixture of triterpenoid and steroidal type, showed an inhibition of fungal growth of 66% (4% concentration, 12 days). In addition, these specialized phytochemicals were not phytotoxic at the antifungal concentrations confirming their potential suitability for horticultural crop protection. Saponins obtained from different Medicago species proved to be strongly active on the phytoparasitic nematodes Xiphinema index, Meloidogyne incognita, and Globodera rostochiensis and generally resulted in mortality rates not significantly different from those of the synthetic nematicide oxamyl. Flavonoids (mainly represented by kaempferol and quercetin rutinosides) and tannins (predominantly of the prodelphinidin type) extracted from sulla proved to be toxic towards the infective juveniles of the root-knot nematode M. incognita, causing a mortality greater than 89% (250 mg mL-1 concentration, 96 hours), similar to that obtained with the chemical treatment with fluopyram [2]. The in vitro nematotoxic activity was also confirmed by using Medicago or sulla biomasses, as soil organic amendments. Both biomasses significantly suppressed M. incognita multiplication and gall formation on tomato roots, as well as nematode infestation in the soil.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
