title: Morphological and karyotypic differences within and among populations of Radopholussimilis.
abstract: Twenty populations of Radopholussimilis from three countries and different hosts (19 populations from ornamental plants and one population from ginger) were compared using morphological characters, morphometrics and karyotype between progeny from both single females and 30 females of each population. Morphological diversity existed in and among the populations, even within the progeny nematodes from single nematodes compared to that of 30 females. The labial disc shape, the number of head annuli, the terminated position of lateral lips, the number of genital papillae before cloacal apertures and female and male tail terminal shape showed variation. In addition, genital papillae arranged in a double row before cloacal apertures was first found in two ornamental populations. The karyotype of all the 20 populations was n = 5. Combining our results and previous studies, we support that Radopholuscitrophilus is a synonym of Radopholussimilis, and that it is not possible to distinguish physiological races or pathotypes of Radopholussimilis according to morphological characters or karyotype.
authors.affiliation: Laboratory of Plant Nematology /Research Center of Nematodes of Plant Quarantine/Province Key Laboratory of Microbial Signals and Disease Control, College of Natural Resources and Environment, South China Agricultural University, Wushan Street, Guangzhou, Guangdong Province, China.
authors.forename: Chun-Ling
authors.initials: CL
authors.lastname: Xu
authors.affiliation: Laboratory of Plant Nematology /Research Center of Nematodes of Plant Quarantine/Province Key Laboratory of Microbial Signals and Disease Control, College of Natural Resources and Environment, South China Agricultural University, Wushan Street, Guangzhou, Guangdong Province, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.affiliation: Laboratory of Plant Nematology /Research Center of Nematodes of Plant Quarantine/Province Key Laboratory of Microbial Signals and Disease Control, College of Natural Resources and Environment, South China Agricultural University, Wushan Street, Guangzhou, Guangdong Province, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xie
authors.affiliation: Laboratory of Plant Nematology /Research Center of Nematodes of Plant Quarantine/Province Key Laboratory of Microbial Signals and Disease Control, College of Natural Resources and Environment, South China Agricultural University, Wushan Street, Guangzhou, Guangdong Province, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Huang
authors.affiliation: Laboratory of Plant Nematology /Research Center of Nematodes of Plant Quarantine/Province Key Laboratory of Microbial Signals and Disease Control, College of Natural Resources and Environment, South China Agricultural University, Wushan Street, Guangzhou, Guangdong Province, China.
authors.forename: Wen-Jia
authors.initials: WJ
authors.lastname: Wu
authors.affiliation: Laboratory of Plant Nematology /Research Center of Nematodes of Plant Quarantine/Province Key Laboratory of Microbial Signals and Disease Control, College of Natural Resources and Environment, South China Agricultural University, Wushan Street, Guangzhou, Guangdong Province, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Yu
authors.affiliation: Laboratory of Plant Nematology /Research Center of Nematodes of Plant Quarantine/Province Key Laboratory of Microbial Signals and Disease Control, College of Natural Resources and Environment, South China Agricultural University, Wushan Street, Guangzhou, Guangdong Province, China.
authors.forename: Dong-Wei
authors.initials: DW
authors.lastname: Wang
keywords: Burrowing nematode; karyotype; morphological comparison; optical and SEM microscopy