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Poster Session: Biology and Disease Management - Nematology


The profile of GHF5 and GHF45 cellulases in 14 Aphelenchoides besseyi isolates orginated from different hosts.
G. WU (1), P. J. Chen (1)
(1) Natl Chung Hsing Univ, Taichung, Taiwan

Cellulase (β-1,4-endoglucanase) and pectate lyase of plant parasitic nematodes are important effectors for disease development. Nematode β-1, 4-endoglucanases have two different topological structures, glycosyl hydrolase family 5 and 45 (GHF5 and GHF45) whose coding genes have been speculated to be originated from bacteria and fungi, respectively by horizontal gene transfer. GHF5 and GHF45 have not been reported to co-exist in a single nematode species. The presence of GHF5 or GHF45 were evaluated in fourteen Aphelenchoides besseyi isolates, of which 6 were collected from bird’s nest fern, 7 from rice and 1 from strawberry. The isolates collected from rice and strawberry did not cause disease symptoms when infiltrated into the leaves of bird’s nest fern. PCR amplification with the GHF5 degenerate primer set produced a single 491 bp band from the bird’s nest fern isolates, whereas no products were detected from the rice or strawberry isolates. GHF45 degenerate primer set amplified two bands of 548 and 439 bp in sizes from the bird’s nest fern isolates and a single smaller band (387 bp) from the rice and strawberry isolates. The results suggested that the A. besseyi isolates collected from bird’s nest fern are unique in which they likely have two different cellulases.