Characterisation of Meloidogyne species from China using isozyme phenotypes and amplified mitochondrial DNA restriction fragment length polymorphism

Forty-six Meloidogyne populations from 14 provinces of China were characterised in terms of malate dehydrogenase, esterase phenotypes and HinfI restriction profiles of amplification products from the mitochondrial DNA ( mtDNA) region between the COII and lrRNA genes. Isozyme phenotyping revealed that 29 of the populations were M. incognita, six were M. javanica, six were M. arenaria, three were M. hapla and two were M. enterolobii. HinfI restriction patterns of the COII-lrRNA region correlated with nematode isozyme phenotypes and enabled reliable differentiation and identification of the five root-knot nematodes occurring in China. The size and sequence of the mtDNA amplification product were determined for the first time for M. enteroloii, a potentially economically important crop pathogen. Sequence comparison showed that the sequence of the intergenic region between the COII and lrRNA genes for M. enterolobii was identical to that reported for M. mayaguensis. Together with published observations on morphology, host range and esterase phenotype of the two nominal species, the mtDNA sequence evidence suggests that M. mayaguensis could be conspecific with M. enterolobii.