Real-Time PCR and Agar Plating Method to Predict Fusarium Verticillioides and Fumonisin B1 Content in Nigerian Maize

Abstract

Eighty maize grain samples collected in Nigeria were investigated for fumonisin B 1 (FB 1 ) content and Fusarium verticillioides colonization. F. verticillioides DNA was quantified by species-specific real-time PCR and living propagules of the fungus were counted by agar-plating method. FB 1 was detected in 55 (68.7%) of the total samples (mean: 98.5 µg/kg, range: 10 to 714 µg/kg) at 10 µg/kg detection limit. The mean amount of F. verticillioides DNA determined by real-time PCR was 49.7 µg/kg (range: 10-126.7 µg/kg), while agar plate method showed the presence of F. verticillioides in 45 samples (mean incidence: 21.0%, range: 6.7-60.0%). There was correlation ties between F. verticillioides DNA by real time PCR and fungal colonization by agar plate method (R = 0.71, p = 00001 at 95% confidence level), and means of FB 1 and F. verticillioides DNA in the yellow and white maize were significantly different. Despite the high consumption of maize in Nigeria, the amount of FB 1 ingested by consumers appears to be low. The estimated daily intake of fumonisins was 0.21 µg/kg body weight per day.

Aflatoxin and fumonisin contamination of yam flour from markets in Nigeria

“…This is the first report on the occurrence of FBs in yam flour in Nigeria. When compared to maize in Nigeria, the levels of FB 1 obtained in this work were lower than that reported by Adejumo, Hettwer, Nutz, and Karlovsky (2009) …”

Determination of the LOQ in real-time PCR by receiver operating characteristic curve analysis: application to qPCR assays for Fusarium verticillioides and F. proliferatum

“…Adejumo et al [ 31 ] compared PCR analysis with an agar plating method for detection of F. verticillioides in maize samples from a Nigerian market. They found that only 71% of the maize samples that were positive for F. verticillioides by agar plating were confirmed positive by species-specific PCR.…”

Tolerance to Fusarium verticillioides infection and fumonisin accumulation in maize F1 hybrids and subsequent F2 populations

“…The amount of F . verticillioides target DNA in a sample represented fungal colonization (Adejumo, Hettwer, Nutz, & Karlovsky, 2009; Janse van Rensburg, Mclaren, Flett, & Schoeman, 2015; Ncube, Flett, Waalwijk, & Viljoen, 2011; Rose et al., 2016).…”

“…The reproducibility (inter-run variance) and repeatability (intra-run variance) of the qPCR was not investigated, as this was previously performed by Boutigny et al (2012) under the same laboratory conditions using the same analytical equipment. The amount of F. verticillioides target DNA in a sample represented fungal colonization (Adejumo, Hettwer, Nutz, & Karlovsky, 2009; Janse van Rensburg, Mclaren, Flett, & Schoeman, 2015;Ncube, Flett, Waalwijk, & Viljoen, 2011;Rose et al, 2016).…”