Sample volume affects the number of Phytophthora and Phytopythium species detected by soil baiting

Abstract More Phytophthora species are detected from environmental samples through DNA metabarcoding than isolated by baiting. We investigated whether bulking soil and baiting ~ 300 g in standard 1 L tubs resulted the isolation of fewer Phytophythium compared with using 15 – 20 non-bulked individual 200 ml tubs. At each four sites dying vegetation, 50 were collected baited separately small tubs, followed plating lesioned baits over 7 days. The number obtained was those subsamples large Half asymptomatic plated on day remaining assessed for presence metabarcoding. Root rhizosphere bulked site also A higher recovered volumes soils. Metabarcoding revealed not baits. roots did reveal any that and/or plating. numbers Phytopythium different methods same trend as . It concluded across a separate results technique soils, this, together baits, detects highest total species.