In vitro evaluation of Colombian plant extracts against Black Sigatoka (Mycosphaerella fijiensis Morelet)

Abstract

In this work, 90 dichloromethane and methanol extracts obtained from 45 plants collected at the Natural Reserve Bremen – La Popa (Colombia) and at the Natural Regional Park Ucumarí (NRPU, Colombia) belonging to five botanical families were evaluated at 1000 mg/l, for their in vitro fungicide activity through the ascospore germ tube elongation and the measurement of the mycelial radial growth of Mycosphaerella fijiensis assays. The methanol extracts from the species Lycianthes acutifolia (Solanaceae) and Piper pesaresanum (Piperaceae); as well as, the dichloromethane extracts from P. pesaresanum and those from the Lauraceae family named Nectandra acutifolia and Ocoteca paulii, all inhibited M. fijiensis ascospore germination in 100% in the germinative tube elongation assay. With regards to the effects of the plant extracts on mycelial radial growth, the methanol extracts from P. pesaresanum and the dichloromethane one from N. acutifolia both showed 100% inhibition in this bioassay. Additionally, from the phytochemical screening on the dichloromethane and methanol extracts it was found that compounds such as alkaloids, phenols and terpenes were present in most of the extracts evaluated and they might be the cause of the antifungal activities reported.

Keywords:

• Antifungal
• bioprospection
• black leaf streak
• crop protection
• phytofungicides
• plant pathogens

Acknowledgements

The authors are very grateful to the Centro de Investigación y Estudios en Biodiversidad y Recursos Genéticos (CIEBREG), The Universidad Tecnológica de Pereira and COLCIENCIAS for the financial support to this project. In addition, the authors are also in debt with the CARDER and CRQ corporations by for granting permission to plant collection.