title: Intraspecific variation in Radopholus similis isolates assessed with restriction fragment length polymorphism and DNA sequencing of the internal transcribed spacer region of the ribosomal RNA cistron.
abstract: Restriction fragment length polymorphism and direct sequencing of the internal transcribed spacer rDNA region of 19 isolates of Radopholus similis yielded significant diversity, both among isolates and within some individuals. Restriction fragment length polymorphism with HaeIII, AluI and Tru9I yielded two sets of patterns. Digestion with RsaI revealed one or two supernumerary bands in single nematodes from five isolates, and sequencing confirmed microheterogeneity in four of these. Phylogenetic analysis grouped most isolates closely together, except for the five isolates with additional bands for RsaI. Our data reveal more population structure than previously found and lend further support to the synonymy of R. similis and 'Radopholus citrophilus'.
authors.affiliation: Department of Crop Protection, Agricultural Research Corporation, P.O. Box 126, Wad Medani, Sudan.
authors.forename: Gamal A A
authors.initials: GA
authors.lastname: Elbadri
authors.forename: Paul
authors.initials: P
authors.lastname: De Ley
authors.forename: Lieven
authors.initials: L
authors.lastname: Waeyenberge
authors.forename: Andy
authors.initials: A
authors.lastname: Vierstraete
authors.forename: Maurice
authors.initials: M
authors.lastname: Moens
authors.forename: Jacques
authors.initials: J
authors.lastname: Vanfleteren
mesh_terms: D000818:Animals; D001483:Base Sequence; D016000:Cluster Analysis; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D014644:Genetic Variation; D008969:Molecular Sequence Data; D028521:Musa; D009348:Nematoda / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D009349:Nematode Infections / Q000469:parasitology*; D010802:Phylogeny; D010935:Plant Diseases / Q000469:parasitology*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011897:Random Allocation; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
chemical_list: D021903:DNA, Ribosomal Spacer