Mycobiota of maize seeds revealed by rDNA‐ITS sequence analysis of samples with varying storage times

Abstract

Fungi are an integral component of the plant microbiome. However, the composition and variation in the fungal communities (mycobiota) associated with seeds are poorly understood. In this study, we investigated the mycobiota of 11 maize seed samples with storage times ranging from 6 months to 12 years. Mycobiota were characterized by a culture-based approach, and fungal species were identified through rDNA-ITS sequence analyses. From a total of 169 pure fungal isolates obtained from both the seed surface and internal tissues, we identified 16 distinct species (belonging to 10 genera) associated with maize seeds, all but one of which were ascomycetes. Among these species, seven were exclusively isolated from internal tissues, two species were isolated only from the seed surface, and another six species were isolated from both the surface and internal tissues. Aspergillus niger was consistently found under all storage conditions and dominated fungal communities with a relative abundance of 36%-100%. Species of Fusarium (9%-40%) and Penicillium (9%-20%) were also frequently isolated, but other species appeared sporadically and were isolated from fewer than three seed stocks. According to our results, while the overall incidence of fungal infection generally declined with storage time, there was no consistent association between seed storage time and fungal species richness or relative abundance; furthermore, the composition of the mycobiota associated with maize seeds was highly variable among the samples. The detection of the four major mycotoxigenic fungal genera, specifically Aspergillus, Fusarium, Penicillium, and Alternaria, was alarming, and the isolation of a potential controlling agent as well as information about their temporal occurrence will contribute to the management of mycotoxins in the future.

Fungal biodiversity on maize kernels in an insecticide evaluation trial

“…with incidences of up to 7.33%, 2.45%, 16.09%, 21.33%, 12.50% and 6.54%, respectively (Figure 1). These accompanying species are common mycobiota on maize kernels in Serbia and worldwide and already confirmed in some previous studies (Krnjaja et al, 2004;Tančić, 2009;Mendoza et al, 2017;Xing et al, 2018;Tóth et al, 2012). The lower incidence of Aspergillus and Penicillium species in the present study is consistent with the findings of Rodríguez Páez et al 2011, who also detected Penicilium spp.…”

Combined Metabarcoding and Co-occurrence Network Analysis to Profile the Bacterial, Fungal and Fusarium Communities and Their Interactions in Maize Stalks

“…Some of the most abundant fungal genera found in the present study, including Fusarium , Epicoccum , Acremonium , Sarocladium , and Phoma had been reported as endophytes isolated from maize (Pan and May, 2009; Amin, 2013; Xing et al, 2018). In particular, Fusarium , Epicoccum , and Phoma were reported as the most abundant endophytes isolated from maize leaves, using two different lineages (Szilagyi-Zecchin et al, 2016), while Acremonium was detected exclusively in Fusarium wilt suppressive soils, but not in conducive soils (Siegel-Hertz et al, 2018).…”

Changes in the Fungal Microbiome of Maize During Hermetic Storage in the United States and Kenya

“…A study by Hill and Lacey (1983) demonstrated the prevalence of yeast-like fungi on the surface of ripening barley as well as the leaf pathogen Alternaria alternata . A study by Xing et al (2018) analyzed the mycobiota of maize kernels stored at room temperature between 6 months and 12 years. Fungi were isolated from both the seed surface and within the kernel using similar methodology to our study.…”