Grain colonization by fumonisin-producing Fusarium spp. and fumonisin synthesis in South African commercial maize in relation to prevailing weather conditions

摘要: Abstract Fumonisins are mycotoxins produced primarily by Fusarium verticillioides and F. proliferatum on maize. These secondary, carcinogenic metabolites with a worldwide distribution. This study was performed to evaluate the relationship between weather variables, colonization of grain F. verticillioides resultant fumonisin contamination. Grain spp. determined using quantitative real-time PCR (qPCR) contamination fumonisins HPLC analysis. Results indicated high natural infection fumonisin-producing concentrations in warmer production areas such as Northern Cape, North West Free State Provinces. Site-specific data, including temperature, radiation, humidity, rainfall evapo-transpiration were provided ARC-Institute for Soil Water Climate's meteorology office. Stepwise multiple regression analysis selected variables mean maximum temperature minimum humidity (days 1–14 post-silking) having significant relationships maize kernels spp.. Further calculated non-linear, 3-dimensional Lorentzian equation (Sigmaplot 10.0). The optimum 28.97, 32.14 30.40 °C humidities at 27.29, 31.86 29.74% respectively over three recorded seasons. application correlation stepdown sequential means data inclusion observed fungal biomass variable, suggested two phases development i.e. tissues during early post-silking stage, followed dough stage fill. Based this statistical model it would appear that specific producing influenced largely less so rainfall. Optimum obtained biomasses 39.94 pg 2007, 47.65 pg 2008 90.69 pg 2009. temperatures 30.33, 31.12 29.80 °C 2007–2009, respectively. Although these models not consistent seasons regard actual prediction values, they regarding time production. It is evident additional driving need be identified.