Detection and Quantification of Fusarium spp. (F. oxysporum, F. verticillioides, F. graminearum) and Magnaporthiopsis maydis in Maize Using Real-Time PCR Targeting the ITS Region

Fusarium spp. and Magnaporthiopsis maydis are soil-inhabiting fungi and respectively the causal agents of fusarium ear rot and late wilt, two important diseases that can affect maize, one of the most important cereal crops worldwide. Here, we present two sensitive real-time PCR TaqMan MGB (Minor Groove Binder) assays that detect and discriminate several Fusarium spp. (F. oxysporum, F. verticillioides, and F. graminearum) from M. maydis. The method is based on selective real-time qPCR amplification of the internal transcribed spacer (ITS) region and allows the quantification of the fungi. The applicability of this newly developed TaqMan methodology was demonstrated in a field experiment through the screening of potentially infected maize roots, revealing a high specificity and proving to be a suitable tool to ascertain Fusarium spp. and M. maydis infection in maize. Its high sensitivity makes it very efficient for the early diagnosis of the diseases and also for certification purposes. Thus, qPCR through the use of TaqMan probes is here proposed as a promising tool for specific identification and quantification of these soil-borne fungal pathogens known to cause disease on a large number of crops.