A procedure for extracting eggs of Meloidogyne spp. from soil was developed by modifying and combining certain existing techniques. Egg masses were elutriated from the soft, gelatinous matrices of the egg masses were dissolved, and the dispersed eggs were stained to facilitate counting. Data on egg population densities thus obtained facilitate the study of population dynamics of Meloidogyne spp...

A survey was conducted to determine the frequency and abundance of Meloidogyne spp. in tomato production sites located in Baix Llobregat County, Barcelona, Spain. Forty-five sites were sampled before planting and at harvest from February to October, 1991. Meloidogyne spp. occurred in 49% of the sites sampled. Preplant population densities ranged from 10 to 220 (x = 110)juveniles/ 250 cm(3) soil...

Root-knot nematodes (Meloidogyne spp.) represent one of the most polyphagous genera of plant-parasitic nematodes. To date, close to 100 valid species are recognized. In contrast to the size of the genus, the majority of past research focused on a small number of species, i.e., the so-called 'major' species M. arenaria, M. hapla, M. incognita, and M. javanica. This review highlights recent work ...

linked and/or gene-based molecular markers have been used widely in marker-assisted selection (mas) to differentiate resistant and susceptible genotypes. resistance to meloidogyne spp. in beta vulgaris l. is mediated by a single dominant gene (r6m-1). using allele-specific primers (asps), an snp marker harboring a single nucleotide polymorphism (a/g), linked to the resistance gene was developed...

Root-knot nematodes are widely distributed throughout the world. Their distribution and economic importance are purported to be related to biological and environmental factors favorable to Meloidogyne spp. A scheme for comparing Meloidogyne spp. with two other genera of diverse biological characteristics is presented to support this hypothesis. It is further suggested that a probability index c...

Research was initiated to physically characterize the mitochondrial genomes of several Meloidogyne spp. and host-races, to address questions regarding their systematics and dispersal, and to assess the possibility of developing molecular diagnostics for these nematodes. Techniques were developed for purification and rapid detection of mitochondrial DNA from root-knot nematodes. Mitochondrial DN...

One hundred thirty-nine cultivars of soybean (Glycine max) in Maturity Groups V, VI, VII, and VIII were evaluated in a greenhouse for resistance to Heterodera glycines races 3 and 14 and Meloidogyne incognita, M. arenaria, and M. javanica. Of the cultivars tested, 37% had resistance to H. glycines race 3 alone, 12% had resistance to both races 3 and 14, and 69% exhibited a moderate or high leve...

The effects of cropping systems (fallow, rotation with sorghum-sudangrass hybrid [Sorghum bicolor x S. sudanense], and continuous soybean [Glycine max]), nematicide (aldicarb) treatment, and soybean cultivar on yield and nematode population densities were studied in a field infested with a mixture of Meloidogyne spp. and Heterodera glycines. Soybean following sorghum-sudangrass yielded 111 kg/h...

Pasteuria penetrans is an obligate, mycelial, and endospore-forming bacterial parasite of Meloidogyne spp. with promise for the management of root-knot nematodes. Our objective was to use regression analysis of developmental time (days) to various temperatures to determine the minimal temperature for growth and development of P. penetrans in Meloidogyne spp. The data set for regression originat...

Several species of plant parasitic nematodes have been encountered in tea soils in different tea-growing areas of the world. Roots and soil were sampled for the presence of plant-parasitic nematodes from tea plantations in Kusuku, the only major tea growing location in Nigeria. Six genera and species of plant-parasitic nematodes were recovered from the rhizosphere soil. Meloidogyne spp., Pratyl...