Root-knot nematodes ( Meloidogyne spp.) are among the main pathogens of tomato ( Lycopersicon esculentum ) worldwide. Plant resistance is currently the method of choice for controlling these pests and all the commercially available resistant cultivars carry the dominant Mi gene, which confers resistance to the three main species Meloidogyne arenaria , M. incognita and M. javanica . However the ...

In order to expand our understanding of the genetics of root-knot nematodes, the variation in nuclear DNA and mitochondrial DNA in Meloidogyne incognita, M. arenaria and M. javanica was investigated. Despite the obligate mitotic parthenogenetic mode of reproduction, a large number of AFLP polymorphisms were observed among all 16 populations studied. Both UPGMA and principle coordinate analyses ...

Phylogenies were inferred from nearly complete small subunit (SSU) 18S rDNA sequences of 12 species of Meloidogyne and 4 outgroup taxa (Globodera pallida, Nacobbus abberans, Subanguina radicicola, and Zygotylenchus guevarai). Alignments were generated manually from a secondary structure model, and computationally using ClustalX and Treealign. Trees were constructed using distance, parsimony, an...

Even though oats (Avena spp.) have the capacity to produce numerous compounds with potential act antagonistically against plant pathogens, studies on genotypic effect of this crop focusing their nematicidal activity are limited. The objective study was verify aqueous extracts prepared biomass oat genotypes, hatching second-stage juveniles root-knot nematodes (Meloidogyne javanica and Meloidogyn...

Enzyme phenotypes were obtained for 291 populations from 16 species of Meloidogyne originating from 65 countries. Soluble proteins from macerates of individual egg-laying females were separated by electrophoresis in 0.7-mm-thick polyacrylamide gels. Enzymes investigated were nonspecific esterases, malate dehydrogenase, superoxide dismutase, and glutamate-oxaloacetate transaminase. Esterases wer...

Proteins and various isozymes were investigated by direct analysis of single specimens in order to check molecular genetic variability, which is not rare in Meloidogyne species in spite of parthenogenetic reproduction. Variability was found in esterases, ocglycerophosphate, malate dehydrogenases, and some other proteins. Other loci appear monomorphic in the genus (for example, catalase), Distin...

A total of 33 corn hybrids were evaluated in a series of greenhouse and field trials to determine if they differed in resistance to either Meloidogyne incognita race 3 or M. arenaria race 1. Reproduction of M. incognita race 3 and M. arenaria race 1 on the hybrids was also compared. Reproduction of M. arenaria differed among corn hybrids after 58 to 65 days in greenhouse experiments; however, r...