Variation in resistance and virulence among demes of a plant host-pathogenmetapopulation

Thrall, PH Burdon, JJ Young, A

Ph. Thrall et al., Variation in resistance and virulence among demes of a plant host-pathogenmetapopulation, J ECOLOGY, 89(5), 2001, pp. 736-748

49

INGLESE

Article

Environment/Ecology

JOURNAL OF ECOLOGY

0022-0477 → ACNP

89

5

2001

736 - 748

ISI

0022-0477(200110)89:5<736:VIRAVA>2.0.ZU;2-F

1 Despite the recognition that spatial structure can have major consequence s for the ecological and evolutionary dynamics of host-pathogen interaction s, few empirical studies have examined how regional processes affect within -population co-evolutionary patterns. 2 Considerable variation was detected within and among denies of a metapopu lation in the resistance of Linum marginale to a range of local isolates of the rust Melampsora lini. Only four resistance phenotypes were common (occ urring at an overall frequency of > 5%) and pathogen populations were simil arly variable, with five out of 44 virulence phenotypes classified as commo n. 3 Resistance and virulence structure were related to the occurrence of two distinct ecotypes of the host. Hill populations were consistently more resi stant than those in bogs and their pathogen populations more virulent. Allo zyme analysis showed a high degree of genetic differentiation between host ecotypes, with fixed allelic differences. Host and pathogen phenotypes were non-randomly distributed between bog and hill sites. 4 When ecotypic differences were factored out, there was clear evidence of a nonrandom spatial distribution of resistance, with nearby populations bei ng more likely to share resistance phenotypes, suggesting at least weak iso lation by distance. While still apparent, this effect was much less noticea ble in the pathogen populations, indicating significant differences in the spatial scale of dispersal of host and pathogen.