Many trophically transmitted parasites manipulate their intermediate host phenotype, resulting in higher transmission to the final host. However, it is not known if manipulation is a fixed adaptation of the parasite or a dynamic process upon which selection still acts. In particular, local adaptation has never been tested in manipulating parasites. In this study, using experimental infections b...

Gene-for-gene (GFG) and matching-allele (MA) models are qualitatively different paradigms for describing the outcome of genetic interactions between hosts and pathogens. The GFG paradigm was largely built on the foundations of Flor's early work on the flax-flax rust interaction and is based on the concept of genetic recognition leading to incompatible disease outcomes, typical of host immune re...

Pseudomonas tabaci (Wolf and Foster) Stevens, produces an exotoxin, detectable as a bacteriumfree, chlorotic halo, surrounding the necrotic focus of infection in the leaf of a susceptible host at the site of inoculation (Braun, 1955). Garber and Heggestad (1958) reported that species of Nicotiana and varieties of Nicotiana tabacum differed in their susceptibility, ranging from highly susceptibl...

we investigated the relations among infection intensity of european mistletoe (viscum album l.) with host tree features in nour forest park, located in caspian forests in north of iran. the number of 30 circular plots with an area of 0.1 ha were sampled in all places have an aggregation of infested trees. parameters including dbh, height, distance to stand edge, distance to conspecific tree, ba...

Pathogen infection is typically costly to hosts, resulting in reduced fitness. However, pathogen exposure may also come at a cost even if the host does not become infected. These fitness reductions, referred to as "resistance costs", are inducible physiological costs expressed as a result of a trade-off between resistance to a pathogen and aspects of host fitness (e.g., reproduction). Here, we ...

Interactions with parasites may promote the evolution of disassortative mating in host populations as a mechanism through which genetically diverse offspring can be produced. This possibility has been confirmed through simulation studies and suggested for some empirical systems in which disassortative mating by disease resistance genotype has been documented. The generality of this phenomenon i...

Sustainably managing plant resistance to epidemic pathogens implies controlling the genetic and demographic changes in pathogen populations faced with resistant hosts. Resistance management thus depends upon the dynamics of local adaptation, mainly driven by the balance between selection and gene flow. This dynamics is best investigated with populations from locally dominant hosts in islands wi...