1. Results Thirty-one Fusarium strains belong to 11 known species (Table 1). Interestingly, the taxonomic status of 36 isolates remains uncertain, within the Fusarium incarnatum-equiseti species complex investigated recently by O’Donnell et al. (2009). This important Fusarium species diversity emphasizes a potential related mycotoxin risk. For example, three species (F. fujikuroi, F. proliferatum, F. verticillioides) are known as fumonisin producers. Sequence analysis of one of the fumonisin biosynthetic genes (FUM21), revealed variations between the sequences from these banana-isolated Chinese strains and sequences from strains of same species having different host and geographical origins (data not shown). The banana fruits hosted also a wide range of other fungal species, from which pathogenic ones such as Colletotrichum musae, Cladosporium cladosporioides, Phaeoseptoria oryzae, Phomopsis sp. (Table 2) Biodiversity of Fusarium on banana fruits in the Chinese province of Hainan Françoise Munaut 1, Aibo Wu 2, Dabing Zhang 2, Carlos Van Peteghem 3, Sarah De Saeger 3, François Van Hove 1 1 Mycothèque de l'Université catholique de Louvain*, Laboratory of Mycology, Earth and Life Institute, Université catholique de Louvain, Croix du Sud 3 box 6, 1348 Louvain-la-Neuve, Belgium 2 Department of Bioscience and Technology, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Dongchuan road, 800, Shanghai 200240, China Dongchuan road, 800, Shanghai 200240, China 3 Laboratory of Food Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, 9000 Gent, Belgium Introduction In the frame of a research project aiming at detection and control of Fusarium and related mycotoxins in various Chinese foodstuffs, the occurrence of Fusarium species on banana fruits was investigated in a geographical area where cultivated and wild banana plants coexist, the southern provinces of Hainan and Yunnan. During a first collect in Hainan in 2009, 111 fungal isolates were obtained from fruits, from which 67 were identified as Fusarium species. A second collect was achieved in September 2010 in the Yunnan province. Mat & Meth 81 samples were obtained from fruits and flowers of living cultivated or wild banana plants (Fig. 1), as well as from fruits bought on local markets. Collect was performed along the roads of the center of Hainan province, near the cities or counties of Chengmai, Nada, Qiongzhong, Baoting, Baisha and Ledong (Fig. 2) The 111 monoconidial strains obtained were transferred on PDA and SNA for morphological observations that allowed the spotting of Fusarium and Fusarium-like strains among the whole set of strains. For those strains, the Elongation factor-1 (EF-1) gene was partially sequenced as it represents one of the most discriminative molecular tools for species distinction within the genus Fusarium. For the ‘non-Fusarium’ strains, one strain representative of each morphotype was selected for DNA extraction and further molecular identification using the most adequate gene (ITS, -tubulin, …) PCR detection of the FUM21 gene was performed using two home- made primer pairs targetting the FUM21 gene of the fumonisin gene cluster: -fvh87, 5' ‑ GTAATGGCWCAAACCCTTGCAATCA ‑ 3‘/ fvh88, 5' ‑ GTCTGGRCGCAAAMGGCKGCATC ‑ 3' -fvh110, 5' ‑ TTGATGGCTCGGATSCACACAG ‑ 3‘/ fvh111, 5' ‑ GAAWGGTCTCTGRGAGCGAAGCTT ‑ 3' Discussion Besides numerous Fusarium strains (67) and Fusarium species (12) (some of them potentially involved in the mycotoxin problematics), numerous other fungal species were isolated what demonstrated that banana plants host an important fungal diversity. The occurrence of Fusarium on wild banana, in an area of origin of the host, questions the occurrence of a possible coevolution phenomenon between both organisms. Perspectives The banana isolates obtained in 2010 will be identified for further biodiversity evaluation and for genetic diversity studies within Fusarium (using AFLP). Correlation between the fungal species diversity and the plant origin will be investigated. Furthermore, the FUM21 gene sequence analyses will be achieved and compared with strains from different hosts and origins. Fig. 1 Wild banana fruits Fig. 2 Collect mission locations 2009 2010 Acknowledgments For the banana collect in the Hainan province, the authors thank Prof. Yixian Xie’s group, Institute of Environment and Plant Protection, Chinese Academy of Tropical Agricultural Sciences *BCCMTM/MUCL is part of the Belgian Co-ordinated Collections of Micro-organisms consortium financed by the Belgian Federal Science Policy Office. Table 1 Number of strains for the 12 Fusarium species detected and amplification of the FUM21 gene Fusarium sp.FUM21 PCR 36 F. incarnatum-equiseti- 7F. solani- 5F. proliferatum+ 3F. incarnatum- 3F. concentricum- 3F. mangiferae- 3F. sacchari- 2F. fujikuroi+ 2F. fractiflexum- 1F. lateritium- 1F. oxysporum- 1F. verticillioides+ +, presence of the expected 1331 bp PCR band; -, absence of the expected PCR band; Fungal species detected Acremonium strictum Arthrobotrys sp. Aurobasidium pullulans Beauveria sp. Botryosphaeria dothidae Cladosporium cladosporioides Colletotrichum acutatum Colletotrichum gloeosporioides Colletotrichum musae Gliocladium roseum Leptosphaerulina sp. (nov?) Letendrae helminthicola Microdochium sp. Penicillium meleagrinum var. viridiflavum Phaeoseptoria oryzae Phoma sp. Phomopsis sp. Plectosphaerella cucumerina Trichoderma atroviride Trichoderma harzianum Undescribed species in Microbotryomycetidae <Heterogastridiales < Heterogastridiaceae Table 2 Fungal species isolated from banana fruits Literature cited O'Donnell K., Sutton D.A., Rinaldi M.G., Gueidan C., Crous P.W., Geiser D.M. 2009 Novel multilocus sequence typing scheme reveals high genetic diversity of human pathogenic members of the Fusarium incarnatum-F. equiseti and F. chlamydosporum species complexes within the United States. J. Clin. Microbiol. 47, 3851-3861.