Symptomatological aspects associated with fungal incidence and fumonisin levels in corn kernels

Abstract

Toxigenic fungi that infect corn grains are among the major problems in Brazil as they are associated with toxicological implications for both humans and animals. Mechanical-physical methods have been used to separate contaminated grains in lots of corn kernels based on the symptoms caused by fungi. The objective of this study was to assess whether the presence or the type of symptoms were associated with fungal incidence and total fumonisin levels in corn kernel samples from the field. Kernels of two hybrids were separated visually into three groups: 1) asymptomatic or symptomatic exhibiting 2) kernel rot or 3) kernel streak symptoms. A high frequency of Fusarium spp. was observed in asymptomatic (69.5%) and kernel rot (69.9%). Stenocarpella sp. and Penicillium sp. were found in kernel rot (16.0%) and kernel streak (44.1%), respectively. High fumonisin levels (7.24 μg.g-1), above the maximum tolerated limit, were detected only in kernel rot. No association between fumonisin levels and the frequency of Fusarium spp. in kernels was found.

Fungal diversity and metabolomic profiles in GM and isogenic non-GM maize cultivars from Brazil

“…A high frequency of Fusarium spp. (70%) was previously observed in maize hybrids in both asymptomatic and maize with visible kernel rot, resulting in total fumonisins being above the legislation limits (7240 μg.kg −1 ; Lanza et al 2017). In recent years, there has been a focus on other emerging potentially toxigenic compounds produced by Fusarium species such as fusaproliferin, beauvericin, enniatins and moniliformin.…”

Delaying harvest for naturally drying maize grain increases the risk of kernel rot and fumonisin contamination

“…F. verticillioides is considered one of the main species of fumonisin-producing fungi in maize grains (Nelson et al 1991;Guo et al 2016). According to Lanza et al (2017), both F. verticillioides and fumonisins occur frequently in asymptomatic maize grains. On the other hand, the incidence of S. maydis in this hybrid was high and, although this fungus is not related to the occurrence of fumonisins, it is one of the main fungi causing ear rot and kernel rot.…”

“…Inverse results were observed for the hybrid Attack, which presented low incidence of kernel rot and higher levels of fumonisin in the grains. Although F. verticillioides and fumonisins may be found in asymptomatic corn grains (Lanza et al 2017), high levels of fumonisins are commonly associated with ear rot incidence (Bowers et al 2013). According to Parsons and Munkvold (2010), grains showing physical injuries have a higher incidence of ear rot and contamination with fumonisins than undamaged grains.…”

“…Maize crops are susceptible to a range of mycotoxigenic fungi that infect and colonize ears, thus causing yield losses, and lowering grain quality and safety during post-harvest (Hermanns et al 2006;Yılmaz and Tuncel 2010;Kamala et al 2016). Among the mycotoxins produced by these fungi, fumonisins, produced primarily by two maize pathogens, Fusarium verticillioides and Fusarium proliferatum, are the most important worldwide given the frequency and levels of contamination (Blandino et al 2009;Folcher et al 2010;Yılmaz and Tuncel 2010;Ferreira et al 2016;Lanza et al 2016Lanza et al , 2017.…”

“…The fumonisin B1 (FB1) is the most frequent and highly toxic, but FB2 and FB3 are also found eventually (Marasas 2001;Samapundo et al 2006;Yılmaz and Tuncel 2010;Bowers et al 2013;Guo et al 2016). FB1 is classified as a human carcinogen (Group 2B) by the International Agency for Research on Cancer (IARC) and is associated with several animal diseases (Jackson and Jablonski 2004;Lanza et al 2017;Lerda 2017).…”