An explicit AFLP-based marker for monitoring Fusarium oxysporum f.sp. strigae in tropical soils

Publication date: October 2015 Source:Biological Control, Volume 89 Author(s): Judith Zimmermann , Madelein de Klerk , Mary K. Musyoki , Altus Viljoen , Alan K. Watson , Fen Beed , Markus Gorfer , Georg Cadisch , Frank Rasche Our objective was to develop an explicit AFLP-marker to quantify the abundance of Fusarium oxysporum f.sp. strigae (Fos), an effective soil-borne biocontrol agent (BCA) against the parasitic weed Striga hermonthica, in tropical soils. The specificity of the AFLP-marker to Fos was confirmed on basis of comparison of Fusarium isolates of differing relatedness to Fos. These consisted of 40 Fos, 17 Fusarium spp. and 68 F. oxysporum isolates retrieved from tropical and temperate ecosystems. The robustness of the AFLP-marker for monitoring Fos was validated in a controlled incubation experiment. In this experiment, we inoculated the known Fos-BCA “Foxy-2” as model organism via seed coating (1.15*105 colony forming units per seed) of a tropical maize (Zea mays L.) variety to a tropical clayey (Humic Nitisol) and a sandy (Ferric Alisol) soil, both with no indigenous Fos infestation. The proliferation of “Foxy-2” was followed at 14, 28 and 42days after start of experiment by Fos-specific quantitative PCR using the AFLP-marker. Moreover, the experimental set-up considered two additional factors: (1) presence of S. hermonthica, and (2) application of Tithonia diversifolia residues as nitrogen-rich resource for supporting “Foxy-2” proliferat...
Source: Biological Control - Category: Biology Source Type: research