Tropentag, September 16 - 18, 2015 in Berlin, Germany "Management of land use systems for enhanced food security – conflicts, controversies and resolutions"

Assesing Vascular Wilt Disease Progression and Severity in Babaco (Vasconcellea heilbornii var. Pentagona Badillo) by Artificial Inoculation under Greenhouse Conditions

¹National University of Loja, Centre of Biotechnology, Ecuador
²Universidad Central Marta Abreu de Las Villas, Faculty of Agricultural Sciences, Cuba
³University of Rostock, Fac. of Agricultural and Environmental Sciences, Germany
⁴Universidad Técnica Particular de Loja, Ecuador

Abstract

Ecuador is a country known for its biological richness, due to a wide variability of climate from polar to tropical, also it has different ecological zones ranging from desert to tropical rainforest. Thus we have, the vast biodiversity in agricultural crops including his ancestors, makes our country unique offering for growing non-traditional species such as Babaco (Vasconcellea heilbornii var. Pentagona Badillo). However, in recent years, our country has suffered a considerable decline in production volumes of Babaco as a result of the disease known as Vascular Wilt Babaco. In our study we assessed the pathogenicity of twelve Fusarium spp. isolates from Babaco plants under greenhouse conditions. To this end, an artificial inoculation procedure was devised and applied to 65 Babaco seedlings in a completely randomised experimental design with five replicates. The substrate used for the experiment consisted of soil-sand-peat mixture (2-1-1) and sterilised at 121°C for two hours. Each Fusarium spp. culture was inoculated to plants roots by the immersion method. To monitor the progression of the disease, the scale proposed by Veintemilla (2000) was used. Fungus re-isolation in the laboratory was performed to re-confirm that the tissue was in fact colonized by the original strain used in each treatment. All data were statistically analysed by SPSS v.22 IBM, using ANOVA and Tukey tests (P<0.05). Our results revealed that four of the twelve isolates showed a high degree of disease severity (CHA 1 F. oxysporum, F. oxysporum COC1, REY1 F. oxysporum and TUN1 F. temperatum) while the rest of clustered on two groups of medium (6 isolates) and low severity (2 isolates). The four highly severe strains are instrumental for molecular studies e.g. mutant generation, fluorescent microscopy of the Fusarium-Babaco pathosystem.

Keywords: Babaco, Fusarium oxysporum, isolation, pathogenisity test, roots immersion

Contact Address: Aminael Sánchez Rodriguez, Universidad Técnica Particular de Loja, San Cayetano Alto Calle París, Loja, Ecuador, e-mail: asanchez2utpl.edu.ec