Abstract

Many Salix species (Salicaceae) have a high energy quotum and efficient nitrogen use, resulting in a high and stable biomass production, making these plants suitable as bioenergy crops. However, Salix coppices are sensitive to herbivory by chrysomelid beetles, such as Phratora vulgatissima L. (Coleoptera: Chrysomelidae), and to maintain high biomass yields over several years, durable plant resistance is necessary. We have developed a reliable and efficient bioassay that can be used as a tool for detection of resistance against P. vulgatissima in Salix. Screening of six clones of one susceptible (Salix viminalis L.) and one resistant (Salix dasyclados Wimm.) willow species, by the response of several life history traits of larval and adult P. vulgatissima, identified egg production as the most reliable trait for resistance. We show that a 2-week bioassay of oviposition rate is sufficient for a trustworthy estimation of both total egg production and survival of adult leaf beetles. In addition, to elucidate the variation in resistance among the studied clones, leaf concentrations of various phenolic compounds were compared with the key life history traits of the beetles. Phenolic compounds, especially salicylates, have previously been reported as the main factor controlling Salix resistance against P. vulgatissima. Indeed we found higher levels of salicylates in the resistant clones and larval performance was negatively correlated to the concentration of salicylates in the leaves. In addition, we found indications of negative effects of a luteolin derivative and quercetin-3-glucoside on leaf beetle performance, but further studies are needed to elucidate the specific roles that the different phenolic compounds play in plant resistance.

Keywords

Salix; Chrysomelidae; salicylate; bioassay; leaf chemistry; phenolic compound; performance; Coleoptera; Salicaceae

Published in

Entomologia Experimentalis et Applicata
2012, Volume: 144, number: 1, pages: 93-100
Publisher: WILEY-BLACKWELL

SLU Authors

• Lehrman, Anna

  • Department of Crop Production Ecology, Swedish University of Agricultural Sciences
    

• Torp, Mikaela

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Stenberg, Johan A.

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Björkman, Christer

  • Department of Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1111/j.1570-7458.2012.01244.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/39926