EXTRACTS OF Cucurbita foetidissima (Kunth) FRUITS INHIBIT THE GROWTH OF PHYTOPATHOGENS OF AGRICULTURAL INTEREST

Abstract

Objective: To evaluate the in vitro effect of Cucurbita foetidissima fruits extracts on the five-day inhibition of mycelial growth of Rhizoctonia, Phytophthora, Fusarium and Botrytis.
Design/methodology/approximation: We carried out a cladistic analysis using non-parametric statistics with WinClada program (ver. 1.00.08) to identify evolutive characters of Cucurbita foetidissima. A discontinuous extraction of Cucurbita foetidissima fruits was realized using methanol during 48 hours at room temperature. Solvent was changed to concentrate and recover extracts. The in vitro evaluation of antifungal activity was measured by phytopathogenic fungi growth in a potato-dextrose-agar medium (pH 5.7). We conclude the usefulness of the extracts when statistical differences were shown at 120 hours of incubation.
Results: All the Cucurbita extracts inhibited the growth of the fungi colonies (p<0.0001), with differential effect depending on the origin of the fruit. Rincón de Romos, Aguascalientes and Villa de Ramos, SLP inhibited 100% of Rhizoctonia growth. Site Salinas, SLP allowed 13.6% growth of Botrytis, and inhibited the total growth of Rhyzoctonia. Extract from site Loreto, Zacatecas inhibited Botrytis, and Rhyzoctonia (100 %). Fusarium spp and Phytophtora spp. recorded an average growth of 46.7% and 42.4%, respectively, with all extracts. We attributed the fungi-inhibition effect due to tetracyclic triterpenes on the fruits.
Limitations of the study/implications: It is necessary to obtain a phytochemical profile of Cucurbita compounds to identify specific effects according to the phytopathogens.
Findings/conclusions: Formulating a fungicide using plant-extracts of local genetic resources can alleviate the dependence from chemicals in order to control fungi diseases on crops.