• Animal Systematics, Evolution and Diversity
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• v.34 no.2
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• pp.110-113
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• 2018

Aphelenchoides nonveilleri $Andr{\acute{a}}ssy$, 1959, belonging to the family Aphelenchoididae Skarbilovich, 1947, is first reported from South Korea. The genus Aphelenchoides Fischer, 1894 includes about 200 species worldwide, but to date only nine Aphelnechoides species have been reported from South Korea. Specimens of A. nonveilleri were collected from the roots and shoot tips of chrysanthemum (Chrysanthemum morifolium Ramat, 1792) from a greenhouse. This species is distinguished from other Aphelenchoides species by its star-shaped mucro on the female tail tip, three lateral incisures, and the length of the post-vulvar uterine sac. Here we provide details of the morphological characters and morpometrics of A. nonveilleri based on optical microscopy.

• Animal Systematics, Evolution and Diversity
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• v.32 no.4
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• pp.253-257
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• 2016

The genus Aphelenchoides (Fischer, 1894) includes a diverse group of species, some of which are of economic importance. A. bicaudatus (Imamura, 1931) Filipjev and Schuurmans Stekhoven, 1941 is reported for the first time from South Korea, with a detailed redescription of the species. Specimens were collected from chrysanthemum (Chrysanthemum morifolium) leaves and shoot tips in South Korea. The species was identified by morphological traits and molecular sequencing. A bifurcated tail distinguishes A. bicaudatus from its congeneric species. To confirm species identification, we determined the partial 18S ribosomal DNA sequence of the specimens and compared with those obtained from other Aphelenchoides species available on GenBank.

• The Plant Pathology Journal
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• v.28 no.4
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• pp.409-417
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• 2012

We identified two novel expansin (EXP) genes in the expressed sequence tag database of Bursaphelenchus xylophilus, designated as Bx-EXPB2 and -EXPB3. Novel Bx-EXPBs encoded 150 amino acids and their similarities in coding sequence were 70.7-84.0% to the previously reported EXPB1 of B. xylophilus. Bx-EXPB2 and Bx-EXPB3 were clustered with Bx-EXPB1 and Bm-EXPB1, respectively, forming the independent phylogeny with other nematode EXPs. All identified Bx-EXPBs contained the signal peptide and were only expressed during the propagative stage, suggesting that they are secreted to facilitate nematode migration through hosts by loosening cell walls during infection. Quantitative real-time PCR analysis showed that the relative accumulation of Bx-EXPB3 mRNAs was the highest among the three Bx-EXPs examined and the order of mRNA accumulation was as follows: Bx-EXPB3 > Bx-EXPB2 >> Bx-EXPB1. Homology modeling of Bx-EXPBs showed that the structurally optimum template was EXLX1 protein of Bacillus subtilis, whichshared residues essential for catalytic activity with Bx-EXPB1 and Bx-EXPB2 except for Bx-EXPB3. Taken together, Bx-EXPB1 and Bx-EXPB2 may be involved migration through plant tissues and play a role in pathogenesis.