title: Host-pathogen diversity in a wild system: Chondrilla juncea-Puccinia chondrillina.
abstract: The resistance structure of a Turkish population of the clonal, apomictic composite Chondrilla juncea and the pathotypic structure of a co-occurring population of its obligate rust pathogen, Puccinia chondrillina, was determined by sequential inoculation of 19 host lines with 15 pathogen isolates each derived from single pustules collected from separate plants among the host population. The resultant matrix of resistant and susceptible reactions provides strong circumstantial evidence for a gene-for-gene interaction. Seven distinct pathotypes were detected in the pathogen population. One of these comprised 53% of the population, a second comprised 13%, while the remaining five pathotypes were each detected only once. The host population was similarly diverse, being composed of eight resistance phenotypes, only two of which were represented by more than one host line. Although C. juncea is apomictic, there was only 58% congruence between host resistance and multi-locus isozyme phenotype categories within this population. Pathotypic phenotypes of 13 other isolates of P. chondrillina collected from ten other Turkish and three more distant populations of C. juncea were markedly different from those found in the population studied in detail. There was no obvious relationship between the degree of geographic separation of pathotypes and their ability to attack particular C. juncea lines in this or three other populations represented by single host lines.
authors.affiliation: CSIRO Biological Control Unit, Campus International de Baillarguet, F-34982 Montferrier sur Lez, France, , , , , , FR.
authors.forename: C
authors.initials: C
authors.lastname: Espiau
authors.affiliation: CSIRO Biological Control Unit, Campus International de Baillarguet, F-34982 Montferrier sur Lez, France, , , , , , FR.
authors.forename: D
authors.initials: D
authors.lastname: Riviere
authors.affiliation: Centre for Plant Biodiversity Research, CSIRO Division of Plant Industry, G.P.O. Box 1600, Canberra, A.C.T. 2601, Australia, , , , , , AU.
authors.forename: J J
authors.initials: JJ
authors.lastname: Burdon
authors.affiliation: CSIRO Biological Control Unit, Campus International de Baillarguet, F-34982 Montferrier sur Lez, France, , , , , , FR.
authors.forename: S
authors.initials: S
authors.lastname: Gartner
authors.affiliation: CSIRO Biological Control Unit, Campus International de Baillarguet, F-34982 Montferrier sur Lez, France, , , , , , FR.
authors.forename: B
authors.initials: B
authors.lastname: Daclinat
authors.affiliation: CSIRO Biological Control Unit, Campus International de Baillarguet, F-34982 Montferrier sur Lez, France, , , , , , FR.
authors.forename: S
authors.initials: S
authors.lastname: Hasan
authors.affiliation: CSIRO Biological Control Unit, Campus International de Baillarguet, F-34982 Montferrier sur Lez, France, , , , , , FR.
authors.forename: P
authors.initials: P
authors.lastname: Chaboudez
keywords: Gene-for-gene interactions; Key words Clonality; Pathogenicity; Resistance; Susceptibility