The tomato Mi-1.2 gene confers resistance against both root-knot nematodes and the potato aphid. Plants are resistant to nematodes early in root development. However, plants as old as 4 weeks are susceptible to aphid infestation. We monitored Mi-1.2 expression at the transcriptional level in resistant (Mi/Mi) and susceptible (mi/mi) tomato cultivars by means of RT-PCR. Mi-1.2 transcripts accumu...

The effects of Meloidogyne incognita or M. javanica at five initial inoculum levels of 20, 100, 200, 1,000, and 2,000 eggs and infective juveniles per seedling on 'Floradade,' 'Nemarex,' 'Patriot,' and 'PI 129149-2(sib)-5' tomatoes maintained at 25 or 32.5 C were studied. The number of egg masses on roots of the susceptible cultivar Floradade was similar for both species of root-knot nematodes ...

the influence of different initial inoculum densities of the root-knot nematode meloidogyne javanica on the growth of sage (salvia officinalis), root-knot development and nematode multiplication was investigated 90 days after inoculation under greenhouse conditions. with the increase in the nematode initial inoculum densities, shoot fresh/dry weight, shoot/root length and root fresh/dry weight ...

Root-knot nematodes (Meloidogyne spp.) are the most common and destructive plant-parasitic nematode group worldwide and adversely influence both crop quality and yield. In this study, a total of 51 root-knot nematode populations from turfgrasses were tested, of which 44 were from North Carolina, 6 from South Carolina and 1 from Virginia. Molecular characterisation was performed on these samples...

A sampling of 15% of the cotton hectarage in each Florida county was assayed for nematodes and soil particle components following the 1990 harvest. The distribution of juveniles of Meloidogyne spp., which were found in 61% of the 178 fields sampled statewide, was not influenced by soil type. Rotylenchulus reniformis was more prevalent in the heavier soils and occurred in 15% of the sampled fiel...

Root-knot nematodes secrete effectors that manipulate their host plant cells so that the nematode can successfully establish feeding sites and complete its lifecycle. The root-knot nematode feeding structures, their "giant cells," undergo extensive cytoskeletal remodeling. Previous cytological studies have shown the cytoplasmic actin within the feeding sites looks diffuse. In an effort to study...

Root-knot nematodes belonging to the genus Meloidogyne are the most economically important group of plant-parasitic nematodes. Thei r worldwide distribution, extensive host ranges, and interaction with other plant pathogens in diseas e complexes rank them among the top plant pathogens affecting the world's food supply (5). Even though only four Meloidogyne species M. incognita, M. javanica, M. ...

Three closely related parthenogenetic species of root-knot nematodes, collectively termed the Meloidogyne incognita-group, are economically significant pathogens of diverse crop species. Remarkably, these asexual root-knot nematodes are capable of acquiring heritable changes in virulence even though they lack sexual reproduction and meiotic recombination. Characterization of a near isogenic pai...

Root-knot nematodes (RKNs, genus Meloidogyne) are a class of plant parasites that seek out and infect the roots many species. The identification RKN attractants can be used in agriculture conjunction with nematode-trapping technology to redirect movements eventually reduce their prevalence field. Here, we discovered some commercial silica gels attract nematodes. Silica contain calcium sulfate. ...

Surveys were conducted in Alexandria, El-Behera, and Matrouh Governorates in northwestern Egypt during the 1994-1998 cropping seasons to study the occurrence, population density, host associations, and distribution of phytoparasitic nematodes associated with 35 major crops, grasses, and weeds. A total of 220 soil and root samples containing mixed populations of 26 genera and 38 species of phyto...