Please use this identifier to cite or link to this item:
標題: Differentiation of the Xiphinema americanum-group nematodes X-brevicollum, X-incognitum, X-diffasum and X-oxycaudatum in Taiwan by morphometrics and nuclear ribosomal DNA sequences
作者: Chen, D.Y.
Ni, H.F.
Yen, J.H.
Cheng, Y.H.
Tsay, T.T.
關鍵字: identification
internal transcribed spacer
interspecific variation
intraspecific variation
juvenile stage
internal transcribed spacer
trichostrongylus nematoda
期刊/報告no:: Nematology, Volume 7, Page(s) 713-725.
摘要: Morphometrics and molecular variability of the X. americamun-group collected in Taiwan were studied. Morphometric data, derived from the females and their developing juveniles, revealed that the 27 populations comprised four taxa: X. brevicollum, X. incognitum, X. diffusum and X. oxycaudatum, the last species being found to have only three juvenile stages. Further identifications were conducted by analysing the nucleotide sequences of the first internal transcribed spacer (ITS-1), 5.8S gene and second internal transcribed spacer (ITS-2) of ribosomal DNA (rDNA). Pairwise comparisons revealed the sequence differences among these taxa ranging from 3.5 to 21.8% for the ITS-1, 2.9 to 28.6% for the ITS-2 and 0 to 3.1% for the 5.8S. Little or no intraspecific variation was detected in the four species for which multiple populations from different geographical regions or hosts were sequenced. Although X. incognitum is morphometrically closer to X. diffusum than it is to X. brevicollum in mean body length, total stylet length, and percentage position of vulva, there is a higher degree of genetic similarity between X. incognitum and X. brevicollum.
ISSN: 1388-5545
Appears in Collections:期刊論文



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.