Species Composition and Toxigenic Potential of Fusarium Isolates Causing Fruit Rot of Sweet Pepper in China

Jianhua Wang,Zhiyong Zhao,Shanhai Lin,Aibo Wu,Shuangxia Wang,François Van Hove

doi:10.3390/toxins11120690

Abstract

Apart from causing serious yield losses, various kinds of mycotoxins may be accumulated in plant tissues infected by Fusarium strains. Fusarium mycotoxin contamination is one of the most important concerns in the food safety field nowadays. However, limited information on the causal agents, etiology, and mycotoxin production of this disease is available on pepper in China. This research was conducted to identify the Fusarium species causing pepper fruit rot and analyze their toxigenic potential in China. Forty-two Fusarium strains obtained from diseased pepper from six provinces were identified as F. equiseti (27 strains), F. solani (10 strains), F. fujikuroi (five strains). This is the first report of F. equiseti, F. solani and F. fujikuroi associated with pepper fruit rot in China, which revealed that the population structure of Fusarium species in this study was quite different from those surveyed in other countries, such as Canada and Belgium. The mycotoxin production capabilities were assessed using a well-established liquid chromatography mass spectrometry method. Out of the thirty-six target mycotoxins, fumonisins B1 and B2, fusaric acid, beauvericin, moniliformin, and nivalenol were detected in pepper tissues. Furthermore, some mycotoxins were found in non-colonized parts of sweet pepper fruit, implying migration from colonized to non-colonized parts of pepper tissues, which implied the risk of mycotoxin contamination in non-infected parts of food products.

Highlights

Sweet pepper or bell pepper (Capsicum annuum L.) is highly appreciated in the fresh vegetable markets worldwide due to its unique taste, aromas, and the multiple culinary uses
The purified isolates were first identified to species with morphological characteristics [21], and this was subsequently confirmed by nucleotide sequences analysis of the translation elongation factor 1-α (TEF-1α) genes with partial of representative strains
F. equiseti, F. solani, and F. fujikuroi were the causal agents of external fruit rot of pepper in China, with F. equiseti being the predominant, while F. equiseti, F. solani, and F. fujikuroi were associated with internal fruit rot of pepper, with F. equiseti being the predominant. This is the first report of F. fujikuroi, F. equiseti, and F. solani associated with external and internal pepper fruit rot in China

Summary

Introduction

Sweet pepper or bell pepper (Capsicum annuum L.) is highly appreciated in the fresh vegetable markets worldwide due to its unique taste, aromas, and the multiple culinary uses. It represents one of the most important vegetables for the high content of phytochemicals, such as ascorbic acid and soluble phenols [1,2], having potential positive effects on human health. Sweet pepper is an economically important vegetable crop and widely used for direct consumption and manufacturing of sauce worldwide, where the global production reached 34.6 million tons of fresh fruit and 3.5 million tons of dried pods [3]. The disease poses a serious limitation to pepper cultivation, resulting in yield reduction or complete crop loss, as reported previously in the literature [4,5,6]

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