Mycosystema. 2013, 32(4): 617-632.
Fusarium species are important pathogens of banana, especially causing such serious diseases as Panama disease and crown rot disease. F. oxysporum f. sp. cubense race 1 (Foc 1) and race 4 (Foc 4) were reported as the pathogenic populations of Panama disease in China, but it has been confused with the Fusarium species of crown rot disease. In order to understand the Fusarium diversities associated with banana in both interspecific and intraspecific levels, 143 Fusarium isolates were cultured from 90 banana samples collected from fruit markets and banana orchards in South China in 2008–2011. Based on morphological observation and phylogenetic analyses with partial translation elongation factor-1 alpha (EF-1α) gene, ten Fusarium species were recognized, including F. oxysporum, F. solani, F. camptoceras, F. pallidoroseum, F. stiloides, F. chlamydosporum, F. verticillioides, F. proliferatum, F. concentricum, F. sacchari, and three undescribed taxa in Gibberella fujikuroi species complex (GFC). F. concentricum is newly recorded in China. F. sacchari is firstly reported from banana. F. concentricum and F. sacchari were the most common GFC species in banana fruits. Phylogenic analyses were conducted for GFC and the F. oxysporum species complex (FOSC). 27 partial EF-1α sequences of GFC strains were employed and seven clades were recognized, including F. verticillioides, F. proliferatum, F. concentricum, F. sacchari and three undescribed lineages recorded as Fusarium sp. 1, Fusarium sp. 2 and Fusarium sp. 3. 50 partial EF-1α sequences of FOSC were employed and their phylogenetic analysis generated two major clades and 12 monophyletic lineages, 21 South China isolates in seven lineages, and 13 pathogenic strains distributing in three of them. The phylogenetic studies showed that the pathogens of Panama disease in China Mainland were closely related to those from Southeast Asia and Taiwan, China and wider genetic differentiation were found among the race 1 strains than the race 4 strains. Race 1 was genetically closer to the isolates obtained from fruits as compared with race 4. It is concluded that more Fusarium species and genetic groups are associated with banana and show plentiful intraspecific diversity.
