Diversity and Toxigenicity of Fungi that Cause Pineapple Fruitlet Core Rot

Abstract

The identity of the fungi responsible for fruitlet core rot (FCR) disease in pineapple has been the subject of investigation for some time. This study describes the diversity and toxigenic potential of fungal species causing FCR in La Reunion, an island in the Indian Ocean. One-hundred-and-fifty fungal isolates were obtained from infected and healthy fruitlets on Reunion Island and exclusively correspond to two genera of fungi: Fusarium and Talaromyces. The genus Fusarium made up 79% of the isolates, including 108 F. ananatum, 10 F. oxysporum, and one F. proliferatum. The genus Talaromyces accounted for 21% of the isolated fungi, which were all Talaromyces stollii. As the isolated fungal strains are potentially mycotoxigenic, identification and quantification of mycotoxins were carried out on naturally or artificially infected diseased fruits and under in vitro cultures of potential toxigenic isolates. Fumonisins B1 and B2 (FB1-FB2) and beauvericin (BEA) were found in infected fruitlets of pineapple and in the culture media of Fusarium species. Regarding the induction of mycotoxin in vitro, F. proliferatum produced 182 mg kg⁻1 of FB1 and F. oxysporum produced 192 mg kg⁻1 of BEA. These results provide a better understanding of the causal agents of FCR and their potential risk to pineapple consumers.

Pineapple Mycobiome Related to Fruitlet Core Rot Occurrence and the Influence of Fungal Species Dispersion Patterns

“…Our results demonstrate that structuration of the fungal flora of fruitlets was mainly composed of two species complexes that were recently characterized as Fusarium fujikuroi and Talaromyces purpureogenus [49,50]. This type of association was previously described in FCR through the isolation of F. verticillioides and T. funiculosus recovered from FCR symptoms [8,51], even though T. funiculosus had never been defined as prevalent in Reunion Island before.…”

“…Particularly, only one Trichoderma species (T. paraviridescens) was isolated, showing a low relative abundance (0.6%) in HF, while this genus was supported by five species in IF (T. asperellum, T. erinaceum, T. harzianum, T. paraviridescens, and T. trixiae) contributing to 4.6% of the identified fungal flora. Although F. ananatum was the most frequently described FCR-associated pathogen [10,11,49], its occurrence and relative abundances were similar in HF and IF, with 11.2% and 10.3%, respectively. Interestingly, F. proliferatum, F. ananatum, F. fujikuroi, F. circinatum, F. oxysporum, F. sacchari, and F. verticillioides all belonged to the Fusarium fujikuroi species complex (FFSC) [49], which represented 43.5% and 37.9% of HF and IF mycobiomes, respectively.…”

“…Although F. ananatum was the most frequently described FCR-associated pathogen [10,11,49], its occurrence and relative abundances were similar in HF and IF, with 11.2% and 10.3%, respectively. Interestingly, F. proliferatum, F. ananatum, F. fujikuroi, F. circinatum, F. oxysporum, F. sacchari, and F. verticillioides all belonged to the Fusarium fujikuroi species complex (FFSC) [49], which represented 43.5% and 37.9% of HF and IF mycobiomes, respectively. Similarly, the Talaromyces purpureogenus species complex was also highly represented following the identification of T. stollii, T. amestolkiae, and T. purpureogenus, together gathering 15.3% of isolates in HF and 17.2% in IF.…”

Levels of filamentous fungi and selected mycotoxins in leafy and fruit vegetables and analysis of their potential health risk for consumers

“…mycotoxicoses [8,11,58,59,12], mycoses (keratitis, onychomycosis, opportunistic invasive fusariosis) [55,56] fusaproliferin, fumonisin B1, B2, B3, moniliformin, beauvericin, others Fusarium solani L(4) mycotoxicoses [60,61] numerous trichothecenes (T-2, DON, others)…”

Phytopathogenic Fungi and Toxicity

“…The diversity and toxigenic potential of fungal species causing fruitlet core rot (FCR) disease in pineapple were investigated by Barral et al [10]. In particular, Fusarium ananatum and Talaromyces stollii are the most spread fungi responsible of FCR and mycotoxins, such as fumonisin B1, fumonisin B2 and beauvericin, were found in infected pineapple fruitlets.…”