The susceptibility of parental and hybrid willows to plant enemies under contrasting soil nutrient conditions |
| |
Authors: | C M Orians T Floyd |
| |
Institution: | (1) Department of Biology, Williams College, Williamstown, MA 01267, USA, US |
| |
Abstract: | We conducted an experimental study of the effects of nutrient addition on the susceptibility of two species of willows (Salix
eriocephala and S. sericea) and their hybrid to a pathogen and several herbivores. We hypothesized that the relative susceptibility of parental and
hybrid willows would depend upon soil nutrient availability and vary among plant enemies. Using potted plants in a common
garden, we found that S. eriocephala was significantly more susceptible to attack by a fungal rust (Melampsora sp.), a leaf-chewing beetle (Popillia
japonica), and a leaf-folding sawfly (Phyllocolpa
nigrita) than was S. sericea. Conversely, S. sericea was significantly more susceptible to attack by a spider mite (Tetranychus sp.) and a leaf-mining caterpillar (Phyllocnistis sp.) than was S. eriocephala. Hybrid susceptibility to Melampsora sp. and to Phyllocnistis sp. resembled S. eriocephala’s, while hybrid susceptibility to Phyllocolpa
nigrita, Tetranychus sp., and Popillia
japonica resembled S. sericea’s. Susceptibility to a sixth enemy, another leaf-mining caterpillar, Phyllonorycter
salicifoliella, did not differ among the parents and hybrid. Susceptibility to herbivores and pathogens increased along a gradient of increasing
fertilizer application, and this effect was independent of plant taxon or enemy. The results of our study point to the contrasting
influences of a taxonomically and functionally diverse enemy community, reinforce the hybrid dominance model of enemy susceptibility,
and demonstrate that physiological stress and enemy susceptibility can be inversely related.
Received: 25 March 1996 / Accepted: 6 August 1996 |
| |
Keywords: | Host plant susceptibility Hybrid performance Logit modeling Salix spp Soil nutrient heterogeneity |
本文献已被 SpringerLink 等数据库收录! |
|