Life SciencesEvolutionary BiologyGeneticsMolecular EvolutionPhylogeneticsPlant Genetics16S Ribosomal Ribonucleic Acid Analysis16S Ribosomal Ribonucleic Acid PhylogenyMicrobial PhylogenyMolecular PhylogenyPhylogenetic Sequence AnalysisPhylogenetic Tree Reconstruction16S Ribosomal Ribonucleic Acid Phylogenetics16S Ribosomal Ribonucleic Acid Sequence AnalysisGenomic Dna AnalysisMeloidogyne TaxonomyNucleotide Substitution ModelsRestriction Site PolymorphismRibosomal Rna Phylogeny
Evolutionary relationships based on nucleotide variation within the D3 26S rDNA region were examined among acollection of seven Meloidogyne hapla isolates and seven isolates of M. arenaria, M. incognita, and M. javanica. Using D3A and D3B primers, a 350-bp region was PCR amplified from genomic DNA and double-stranded nucleotide sequence obtained. Phylogenetic analyses using three independent clustering methods all provided support for a division between the automictic M. hapla and the apomictic M. arenaria, M. incognita, and M. javanica. A nucleotide sequence character distinguishing M. hapla from the three apomictic species was a 3-bp insertion within the interior of the D3 region. The three apomictic species shared a common D3 haplotype, suggesting a recent branching. Single M. hapla individuals contained two different haplotypes, differentiated by a Sau3AI restriction site polymorphism. Isolates of M. javanica appeared to have only one haplotype, while M. incognita and M. arenaria maintained more than one haplotype in an isolate.
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