Abstract

Potato late blight, caused by Phytophthora infestans, is a major disease in potato production throughout the world. In southern Sweden, hairy nightshade (Solanum physalifolium), an alternative non-crop host to the pathogen, is an increasing weed problem. Single-lesion leaves infected by P. infestans were collected from potato and hairy nightshade to determine phenotypic and genotypic population differentiation of P. infestans between the two hosts. Genotypic variation was estimated using microsatellites as markers. The results showed no genotypic differentiation in the samples between the two hosts. Aggressiveness tests were performed using the sampled isolates to cross-inoculate potato and hairy nightshade. The proportion of infected leaves, latency period, lesion growth rate, and sporulation capacity were measured. For isolates from hairy nightshade, the odds of infection were higher on both hosts combined. When tested on potato leaves, isolates from hairy nightshade showed a significantly shorter latency period and higher sporulation capacity compared with isolates from potato. This indicates that an alternative host can filter populations of P. infestans toward a higher aggressiveness, which could lead to increasing problems in controlling potato late blight.

Published in

Phytopathology
2012, Volume: 102, number: 4, pages: 429-433
Publisher: AMER PHYTOPATHOLOGICAL SOC

SLU Authors

• Sjöholm, Lina

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Andersson, Björn

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Yuen, Jonathan

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Agricultural Science


Publication identifier

DOI: https://doi.org/10.1094/PHYTO-07-11-0192

Permanent link to this page (URI)

https://res.slu.se/id/publ/41783