Taxonomic Study Of Fusarium Species From Major Crops And Their Rhizospheric Soil In Heilongjiang Province

The genus Fusarium Link is one of the most important groups of fungi, which is widely distributed in soil and organisms of animals and plants. Many species of Fusarium are well-known pathogenic fungi in some crops, and they often cause serious diseases and significantly reduce crop production. Some plant pathologists have been encountering taxonomic problems of Fusarium in their work. Heilongjiang is one of major agricultural province in China. Correct identification of Fusarium species from majoy crops and their rhizospheric soil in Heilongjiang province must benefit a good understanding of Fusarium occurrence and distribution in nature. Confirm Fusarium species of Heilongjiang province could enrich Chinese Fusarium resources and provide a solid base for control of plant diseases caused by Fusarium species.From July 2007 to September 2008, one hundred seventy four samples of different plants and their rhizospheric soil were collected from the crop growing areas of tweenty two cities or counties in Heilongjiang province. Using tissue isolation and soil plate isolation method, a total of seven hundred and eight six Fusarium isolates were acquired. Based on the examination and comparison on the mycelium growth rate, colony form, morphology and character of conidia, conidiogenus cell and chlamydospore, sixteen Fusarium species were identified, including F. acuminatum, F. avenaceum, F. chlamydosporum, F. coeruleum, F. culmorum, F. equiseti, F. graminearum, F. lateritium, F. oxysporum, F. proliferum, F. redolens, F. semitactum, F. solani, F. subglutinans, F. udum and F. verticillioides. The morphological characteristics of each Fusarium species were described in the present research together with micrographs and discussion. Among the acquired Fusarium species the largest number of isolated species were F. oxysporum(31.17%), F. solani(28.12%) and F. equiseti(22.77%). The three species were the predominant Fusarium species of Heilongjiang province. F. oxysporum and F. solani were distributed in almost all cities or counties in Heilongjiang province. The percentage of F. chlamydosporum, F. lateritium, F. redolens, F. subglutinans and F. udum of the total Fusarium species were less than 1%. Among the eight species of Fusarium isolated from root-rot soybean plants in Heilongjiang province, F. oxysporum and F. solani were the predominant population. Two suspected Fusarium isolates were further analyzed by EF-1αgene sequencing and the results confirmed their Taxonomic status.They are F. oxysporum andF. redolens.