Incidence, Molecular Characteristics and Pathogenicity of Gibberella fujikuroi Species Complex Associated with Rice Seeds from Asian Countries.
Gibberella fujikuroi species complex (GFSC) was isolated from rice (Oryza sativa L.) seed samples from ten Asian countries and investigated for incidence of GFSC, molecular characteristics, and pathogenicity. Regardless of geographic origin, GFSC was detected with incidences ranging from 3% to 80%. Four species, Fusarium fujikuroi, F. concentricum, F. proliferatum, and F. verticillioides, were found to show an association with rice seeds, with F. fujikuroi being the predominant species. In phylogenetic analyses of DNA sequences, no relationship was found between species, isolates, and geographic sources of samples. Unidentified fragments of the β-tubulin gene were observed in ten isolates of F. fujikuroi and F. verticillioides. With the exception of three isolates of F. fujikuroi, F. fujikuroi, F. proliferatum, and F. verticillioides were found to have FUM1 (the fumonisin biosynthetic gene); however, FUM1 was not found in isolates of F. concentricum. Results of pathogenicity testing showed that all isolates caused reduced germination of rice seed. In addition, F. fujikuroi and F. concentricum caused typical symptoms of bakanae, leaf elongation and chlorosis, whereas F. proliferatum and F. verticillioides only caused stunting of seedlings. These findings provide insight into the characteristics of GFSC associated with rice seeds and might be helpful in development of strategies for management of bakanae.
National Agrobiodiversity Center, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-853, Korea.
Young-Ah
YA
Jeon
Department of Applied Biology, Chungnam National University, Daejeon 305-764, Korea.
Seung-Hun
SH
Yu
National Agrobiodiversity Center, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-853, Korea.
Young Yi
YY
Lee
National Agrobiodiversity Center, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-853, Korea.
Hong-Jae
HJ
Park
National Agrobiodiversity Center, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-853, Korea.
Sokyoung
S
Lee
National Agrobiodiversity Center, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-853, Korea.
Jung Sook
JS
Sung
National Agrobiodiversity Center, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-853, Korea.
Yeon-Gyu
YG
Kim
National Agrobiodiversity Center, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-853, Korea.
Ho-Sun
HS
Lee
Gibberella fujikuroi species complex; Incidence; Molecular characteristics; Pathogenicity; Rice seed