In vitro Antifungal Activity of Different Plant Extracts against Phytophthora infestans the Causal Agent of Potato Late Blight

• Main Authors: Saida Messgo-Moumene, Rym Boukhalfa, Djazia Belaïdi, Lyes Beninal, Siham Haddadj-Hamdi, Mohamed Bellatreche
• Format: Article
• Language: English
• Published: Institution of the Agricultural Research and Higher Education 2017-06-01
• Series: Tunisian Journal of Plant Protection
• Subjects: Biocide effect; Phytophthora infestans; plant aqueous extracts; polyphenols; Solanum tuberosum
• Online Access: http://www.tjpp.tn/SiteWeb/CurrentIssue/3Momen.pdf
• ISSN: 1737-5436; 2490-4368

Our study aimed to evaluate the in vitro antifungal activity of aqueous extracts prepared from seven medicinal plants (Carya illinoinensis, Equisetum arvense, Rosmarinus officinalis, Pistacia lentiscus, Mentha suaveolens, Punica granatum, and Posidonia oceanica) against A1 and A2 isolates of Phytophthora infestans the causal agent of potato late blight. The crude (100%) plant extracts were prepared by decoction and tested at various concentrations (70, 50, 30 and 10% v/v) for determining their relative effectiveness against target pathogen. Their antifungal potential was assessed based on their ability to inhibit pathogen mycelial growth, sporulation, germination and their capacity to affect pathogen in vitro and in vivo survival after treatment. Tested aqueous extracts showed a variable efficiency. For all noted parameters, the greatest inhibition rates were recorded using aqueous extracts from P. granatum bark and from P. lentiscus leaves and berries (88%) used at the concentration of 10% v/v. Their antifungal potential was expressed by lysis of mycelia and sporangia as well as inhibition of P. infestans mycelial growth. Chemical analysis of phenolic compounds of tested aqueous extracts revealed a close relationship between their contents in total polyphenols and the observed antifungal activity. This study clearly demonstrated that pomegranate bark and leaves or berries mastic can be explored as potential sources of bioactive molecules for potato late blight control.