EFFICIENCY OF OVIDIA ANDINA EXTRACTS IN THE CONTROL OF THE PLANT PATHOGEN RHIZOCTONIA SOLANI
The evaluation of plant extracts as disease suppressive is an option to look for alternative crop health management options. Pillo-pillo (Ovidia andina, Thymelae-aceae) is native to southern Argentina and Chile. O. andina extracts control plant damaging arthropods. Our objective was to evaluate O. andina extracts for the control of the plant pathogen Rhizoctonia solani. Powdered and dried aerial parts were successively extracted by maceration with dichloromethane (CH2Cl2) and methanol. Aqueous extract was obtained by decoction of aerial plant parts. The fungus was cultivated on PDA added with CH2Cl2 extract (diluted in CH2Cl2), methanolic, ethanolic and aqueous extract (diluted in ethanol), and hydrodistillation remaining water (diluted in H2O), all at 1:10 and 1:100 v/v (controls: CH2Cl2, ethanol, water). Pathogen growth was significantly reduced by 1:10 CH2Cl2 extract, showing hyphal alterations. When five CH2Cl2 extract fractions diluted in CH2Cl2 were tested, fraction 5 showed equal efficiency as the whole extract. To evaluate extract effect on fungal colonization of plant organs, beetroot glomerules incubated in R. solani colonized soil were recovered, blotted dry and submerged in 1:10 CH2Cl2 extract for 30, 60, 90, 120, or 150 s (controls: water, CH2Cl2). Glomerules were again recovered, blotted dry, and incubated on PDA for pathogen emergence. Infection was significantly reduced by extract treatments for 120 s. These results are the basis of future greenhouse experiments and led us to continue with further phytochemical investigation of O. andina. Bioguided fractionation of the extracts will enable us to search for new antifungal compounds.
Tito Mansilla, J., Broussalis, A.M., Tarcaya , V.P., Cufre, I.M., Rivera, M.C., Fabrizio , M.C. and Wright, E.R. (2012). EFFICIENCY OF OVIDIA ANDINA EXTRACTS IN THE CONTROL OF THE PLANT PATHOGEN RHIZOCTONIA SOLANI. Acta Hortic. 933, 547-552
CH2Cl2 extract, fractions, fungal growth, cumarines, flavonoids