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Host-parasite Relationships (host-parasite + relationships)
Selected AbstractsBook review: Primate Parasite Ecology: The Dynamics and Study of Host-Parasite RelationshipsAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2010David N. M. Mbora No abstract is available for this article. [source] A new root-knot nematode, Meloidogyne silvestris n. sp. (Nematoda: Meloidogynidae), parasitizing European holly in northern SpainPLANT PATHOLOGY, Issue 3 2009P. Castillo High infection rates of European holly (Ilex aquifolium) feeder roots by an unknown root-knot nematode were found in a holly forest at Arévalo de la Sierra (Soria province) in northern Spain. Holly trees infected by the root-knot nematode showed some decline and low growth. Infected feeder roots were distorted and showed numerous root galls of large (8,10 mm) to moderate (2,3 mm) size. Morphometry, esterase and malate dehydrogenase electrophoretic phenotypes and phylogenetic trees of sequences within the ribosomal DNA (rDNA) demonstrated that this nematode species differs clearly from other previously described root-knot nematodes. Studies of host-parasite relationships showed a typical susceptible reaction in naturally infected European holly plants, but did not reproduce on a number of cultivated plants, including tomato, grapevine, princess-tree and olive. The species is described here, illustrated and named as Meloidogyne silvestris n. sp. The new root-knot nematode can be morphologically distinguished from other Meloidogyne spp. by: (i) roundish perineal pattern, dorsal arch low, with fine, sinuous cuticle striae, lateral fields faintly visible; (ii) female excretory pore level with stylet knobs, or just anterior to them, EP/ST ratio about 0ˇ8; (iii) second-stage juveniles with hemizonid located 1 to 2 annuli anterior to excretory pore and short, sub-digitate tail; and (iv) males with lateral fields composed of four incisures, with areolated outer bands. Phylogenetic trees derived from maximum parsimony analysis based on 18S, ITS1-5ˇ8S-ITS2 and D2,D3 of 28S rDNA showed that M. silvestris n. sp. can be differentiated from all described root-knot nematode species, and it is clearly separated from other species with resemblance in morphology, such as M. ardenensis, M. dunensis and M. lusitanica. [source] Pathogenicity and host-parasite relationships of the root-knot nematode Meloidogyne incognita on celeryPLANT PATHOLOGY, Issue 5 2008N. Vovlas Pathogenicity and host-parasite relationships in root-knot disease of celery (Apium graveolens ) caused by Meloidogyne incognita race 1 were studied under glasshouse conditions. Naturally and artificially infected celery cv. D'elne plants showed severe yellowing and stunting, with heavily deformed and damaged root systems. Nematode-induced mature galls were spherical and/or ellipsoidal and commonly contained more than one female, males and egg masses with eggs. Feeding sites were characterized by the development of giant cells that contained granular cytoplasm and many hypertrophied nuclei. The cytoplasm of giant cells was aggregated along their thickened cell walls and consequently the vascular tissues within galls appeared disrupted and disorganized. The relationship between initial nematode population density (Pi) and growth of celery plants was tested in glasshouse experiments with inoculum levels that varied from 0 to 512 eggs and second-stage juveniles (J2) mL,1 soil. Seinhorst's model y = m + (1 , m)zP,T was fitted to height and top fresh weight data of the inoculated and control plants. The tolerance limit with respect to plant height and fresh top weight of celery to M. incognita race 1 was estimated as 0ˇ15 eggs and J2 mL,1 soil. The minimum relative values (m) for plant height and top fresh weight were 0ˇ37 and 0ˇ35, respectively, at Pi , 16 eggs and J2 mL,1 soil. The maximum nematode reproduction rate (Pf/Pi) was 407ˇ6 at an initial population density (Pi) of 4 eggs and J2 mL,1 soil. [source] | ||||||||||