The Identification Of The Fusarium Spp. From Hainan Island

Fusaria or Fusarium fungi are the joint name of genus of Fusarium Link. which are very important to human being and have a very wide distribution in the nature. Fusarium fungi are able to play not only the rule of pathogens and cause serious plant diseases, but also the rule of agents for fermentation and biological control on plant diseases. Survey on the species of Fusarium fungi is absolutely significant for the quarantine, plant disease control and the use of Fusarium resources.In this study, a total of 76 samples were collected from 28 crops distributed at 65 locations, 14 counties in Hainan Island. After culture and single spore isolation, 50 Fusarium isolates were obtained. Based on the examination and comparison on the mycelium growth rate, colony form, morphology and character of sclerotia, conidia, sexual stage structures and sporulating cells, these 50 isolates were primarily identified as 9 Fusarium species, i.e. Fusarium bulbigenum var. niveum, F. solani, F. oxysporum, F. chlamydosporum, F. nivale, F. sporotrichioides, F. equiseti, F. moniliforme and F. javanicum. From these primarily identified species, 14 representative isolates were chosen for further confirmation with molecular techniques. The genome DNAs were isolated from these representative isolates and were used as templets in PCR using the primers specific to Fusarium Link. The expected DNA sequence was amplified from all the templets corresponding to the isolates tested, while no any DNA sequence was amplified from the templets corresponding to the controls (Colletotrichum gloeosporioide,Botryodiplodia theobromae and Nigrospora oryza). These results confirmed that the isolates used in morphological identification were really the Fusarium ones. ITS sequences of these 14 representative isolates were also amplified by PCR and used for compared and the establishment of the phylogenetic tree. By analysis on this tree, all the isolates fell into an identical species by morphological identification fell into an identical category in phylogenetic tree, and vice versa. These results confirmed the morphological identification, and also confirmed the reliability of the use of ITS sequences for Fusariium identification and classification.