Crude extracts of Drimys winteri bark to inhibit growth of Gaeumannomyces graminis var. tritici

Nelson Zapata1*, Marisol Vargas1, Manuel Monsálvez1, and Ricardo Ceballos2

The aim of this study was to assess the effect of Drimys winteri J.R. Forst. & G. Forst. bark and its extracts, obtained sequentially with n-hexane, acetone, and methanol, against Gaeumannomyces graminis var . tritici (Ggt). Ground bark of D. winteri was mixed with potato dextrose agar growth media at concentrations of 250, 500, 1000, 2000, and 4000 mg L-1 in Petri plates. Each extract was mixed at concentrations of 100, 200, 400, and 800 mg L-1. Petri plates were inoculated in the center with a 5-mm mycelium disk and were incubated at 24 ± 1 ºC. Daily measurements of mycelium radial growth were taken to determine growth rate and growth inhibition (%). A ground bark concentration of 978 mg L-1 was needed to inhibit Ggt growth by 50%, while extracts obtained with n-hexane and acetone only required 198 and 234 mg L-1, respectively. The methanol extract only inhibited Ggt growth by 33% when tested at the highest concentration. In conclusion, ground bark and crude extracts, obtained sequentially with n-hexane, acetone, and methanol, from D. winteri bark inhibit Ggt growth when applied in vitro. The n-hexane extract showed the highest inhibitory growth activity.

Keywords: Wheat take-all, soil borne, plant extracts, Ggt.
1Universidad de Concepción, Facultad de Agronomía, Av. Vicente Méndez 595, Casilla 537, Chillán, Chile. *Corresponding author (nzapata@udec.cl).
2Instituto de Investigaciones Agropecuarias INIA, Casilla 426, Chillán, Chile.