Isolation and characterization of Fusarium verticillioides from maize in eastern China

Abstract

In 2012, we isolated mycotoxigenic fungi from maize kernels sourced in Jiangsu and Anhui provinces, China. Fusarium spp. accounted for most isolates detected, followed by Aspergillus and Penicillium spp. Of the Fusarium species, Fusarium verticillioides was the most prevalent, as revealed by direct PCR of DNA from kernel samples, followed by F. proliferatum and F. graminearum. Most F. verticillioides strains contained the FUM1 gene, the product of which plays a key role in fumonisin biosynthesis. In terms of mating type idiomorphs, about 80 % of all strains carried the MAT-1 allele, and 20 % carried MAT-2. The genetic structures of 192 representative F. verticillioides isolates were determined via an analysis of eight simple sequence repeat markers. This analysis revealed highlevel gene diversity but low linkage disequilibrium in three populations grouped by the geographical areas in which they were collected. The three populations exhibited low-level genetic differentiation and high gene flow, indicating that geographical differences minimally influenced population differentiation; all three populations were potentially components of a larger, randomly mating population.

Crops are a main driver for species diversity and the toxigenic potential ofFusarium isolates in maize ears in China

“…F. verticillioides is the dominant species that occurred in all provinces. This is in agreement with previous studies in eastern China (Qiu et al, 2015;Zhang et al, 2013b). F. verticillioides is also the most commonly isolated fungus from maize across the world (Aguin et al, 2014;Madania et al, 2013;Torres et al, 2001), while also F. proliferatum and F. subglutinans are commonly associated with FER.…”

“…boothii was identified in both northwest and northeast of China. This species has not been found on maize in China in previous reports maybe due to the detection methods (Ndoye et al, 2012;Qiu and Shi, 2014;Qiu et al, 2015). F. boothii has been identified in many countries including Ethiopia , Argentina (Sampietro et al, 2010), Kenya (Wagacha et al, 2010), South Africa (Boutigny et al, 2011), Nepal (Desjardins and Proctor, 2011), Mexico (Malihipour et al, 2012), and Korea .…”

“…Therefore, investigating the Fusarium species and their mycotoxins associated with FER in maize is indispensable for sustainable agriculture in China. There have been a few reports focusing on particular regions in China (Ndoye et al, 2012;Qiu et al, 2015;Zhang et al, 2013b). Recently, Fu et al (2015) investigated the Fusarium species associated with maize kernels from nine provinces in China based on a large collection (n=2,321).…”

“…However, the methodology applied by these researchers does not allow sufficient species discriminatio. Qiu et al (2015) found fumonisin producing F. verticillioides to be the most prevalent on maize in southern provinces Jiangsu and Zhejiang, but these are no main maize producing areas. So a detailed description of all Fusarium species causing FER in the main maize producing areas in China is still unknown.…”

“…Many FFSC species can produce fumonisins, a family of mycotoxins, causing various diseases in animals, and it has been associated epidemiologically with oesophageal cancer as well as neural tube defects in some human populations (Gelderblom et al, 1988;Marasas et al, 2004). In maize, Fusarium verticillioides, Fusarium proliferatum and Fusarium subglutinans are the most prevalent species worldwide (Adejumo et al, 2007;Aguin et al, 2014;Madania et al, 2013;Qiu et al, 2015;Torres et al, 2001). The first two species are potential fumonisin producers (Logrieco et al, 2002), while F. subglutinans is generally believed to be a fumonisin non-producer as the fumonisin biosynthetic genes are absent (Proctor et al, 2004).…”