Toxigenic profiles and trinucleotide repeat diversity of species isolated from banana fruits.

Infesting species isolated from banana fruit samples were identified and quantified by morphological, mycotoxicological and molecular tools. A total of 19 isolates were obtained: was most predominant (26%), followed by (16%), (16%), (10.5%), (10.5%), (10.5%) and (5%). Fumonisin B1, deoxynivalenol and zearalenone contents were assayed by high-performance liquid chromatography (HPLC). Seventeen isolates, belonging to , , , , , and spp., produced mycotoxins when cultured on rice medium. Fumonisin was produced by all of the studied isolates, except , at a concentration of over 1 μgmL. isolates 4 and 5 and isolate 3 were the most potent producers of deoxynivalenol. We compared the 19 isolates based on the bands amplified by 10 microsatellite primers. Of these, seven primers, (TCC)5, (TGG)5, (GTA)5, (ATG)5, (TAC)5, (TGC)5 and (TGT)5, yielded a high number of bands and different mean number of alleles. The similarity level between isolates was calculated using a simple matching coefficient. Dendrograms were constructed by the unweighted pair-group method with arithmetical averages (UPGMA). Two main clusters were observed. The interspecific genetic similarity between spp. isolates was between 40% and 58% and the intraspecific similarity from 58% to 100%, indicating a high degree of genetic diversity in the tested isolates. Some unexpected genetic similarities were observed among the isolates, indicating non-agreement between morphological and molecular identification of the isolates.