Penetration and development of juveniles of tobacco cyst nematode (Globodera tabacum solanacearum) on a resistant (NC567) and a susceptible (K326) cultivar of flue-cured tobacco (Nicotiana tabacum L.) were determined in root zone chamber experiments. More vermiform juveniles developed into a swollen shape at 22, 27, and 31 degrees C than at 17 degrees C. Development of flask-shaped nematodes ap...

Southern analysis showed that Gr-EXPB1, a functional expansin from the potato cyst nematode Globodera rostochiensis, is member of a multigene family, and EST data suggest expansins to be present in other plant parasitic nematodes as well. Homology modeling predicted that Gr-EXPB1 domain 1 (D1) has a flat beta-barrel structure with surface-exposed aromatic rings, whereas the 3D structure of Gr-E...

Overman and Woltz (3) indicated that amino acid antimetabolites applied to tile soil suppressed reproduct ion of Paratrichodorus minor (Trichodorus christiei) and root galling caused by Meloidogyne incognita on tomatoes. Eight DL-amino acid antimetabolites similarly decreased the population of Aphelenchoides ritzemabosi on Lucerne, whereas DL-alanine suppressed the populat ion of Heterodera spp...

The greatest constraint to potato production in the United Kingdom (UK) is damage by the potato cyst nematodes (PCN) Globodera pallida and G. rostochiensis. Management of PCN depends heavily on nematicides, which are costly. Of all the inputs in UK agriculture, nematicides offer the largest potential cost savings from spatially variable application, and these savings would be accompanied by env...

The effective management of cyst nematodes requires accurate assessments of the species composition and size of field populations. Compared to traditional diagnostics the polymerase chain reaction offers high specificity, sensitivity and a more rapid means of identifying large numbers of cyst nematode samples. PCRRFLP of the ITS I ribosomal DNA region from Heterodera and Globodera species produ...

Punctodera chalcoensis Stone et al. is a cyst nematode parasitizing corn (Zea mays L.) and teosinte (Zea mexicana (Schrad.) Kuntz) in Mexico (7). This nematode damages corn severely in Tlaxcala and Puebla states of Mexico (7). Pathogenic studies of P. chalcoensis on corn have been conducted in the greenhouse (2). Mundo-Ocampo and Baldwin (6) reported that P. chalcoensis induces a syncytium in r...

Tobacco cyst nematode (Globodera tabacum solanacearum) isolates were collected from 11 locations in Virginia, 3 in North Carolina, and 1 in Maryland. Isolates from each location were maintained and increased on flue-cured tobacco, Nicotiana tabacum cv K326. Plants of flue-cured tobacco cultivars K326 (susceptible) and NC567 (resistant) were each inoculated with 6,000 G. t. solanacearum eggs/pla...

Plant parasitic nematodes (PPN) locate host plants by following concentration gradients of root exudate chemicals in the soil. We present a simple method for RNA interference (RNAi)-induced knockdown of genes in tomato seedling roots, facilitating the study of root exudate composition, and PPN responses. Knockdown of sugar transporter genes, STP1 and STP2, in tomato seedlings triggered correspo...

The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a 'top 10' list of these pathogens based on scientific and economic importance. Any such list will not be definitive as economic importance will vary depending on the region of the world in which a researcher is based. However, care was taken to include researchers from a...

Secondary metabolites from Bupleurum salicifolium were tested against viruses, Gram-positive and Gram-negative bacteria, the yeast Candida albicans, the nematodes Globodera pallida and G. rostochiensis, the insect Spodoptera littoralis and the crustacean Artemia salina. These compounds were also tested against tumoral and non-tumoral cell lines. The polyacetylene 8S-heptadeca-2(Z)-9(Z)-diene-4,...