Intraspecific variation in Capsella bursa-pastoris in plant quality traits for insect herbivores

• Published in: Weed research Vol. 48; no. 2; pp. 147 - 156
• Main Authors: KARLEY, A J, HAWES, C, IANNETTA, P P M, SQUIRE, G R
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.04.2008; Blackwell Science
• Subjects: aphid; Aphididae; Aphis fabae; arable; Biological and medical sciences; Capsella; Capsella bursa-pastoris; carbon nitrogen ratio; flowering; functional diversity; functional trait; Fundamental and applied biological sciences. Psychology; germination; herbivore; intraspecific variation; leaves; life history; Myzus persicae; nitrogen; nitrogen content; nutrient content; nymphs; Parasitic plants. Weeds; phloem; Phytopathology. Animal pests. Plant and forest protection; phytophagous insects; vegetative growth; water content; weed; Weeds; Aphis fabae; functional trait; Weed; herbivore; Myzus persicae; arable; Phytophagous; Capsella bursa-pastoris; Cruciferae; Dicotyledones; Weed science; Quality; Angiospermae; Spermatophyta; Intraspecific comparison; aphid
• ISSN: 0043-1737; 1365-3180
• DOI: 10.1111/j.1365-3180.2007.00617.x

Summary The arable plant Capsella bursa‐pastoris is phenotypically variable in many life history traits, particularly time from germination to flowering. The hypothesis was investigated that, associated with this variation, there are differences in traits that influence plant quality for insect herbivores. Significant within‐species variation was found in plant growth, leaf surface characteristics and tissue nutrient composition among 21 accessions of Capsella. Short flowering time plants exhibited slow vegetative growth, relatively large shoot nitrogen content, high leaf hair densities and differences in phloem composition, compared with long flowering time plants. Insect herbivore response to distinctive trait combinations was assessed on a subset of seven accessions using the phloem‐feeding aphids Aphis fabae and Myzus persicae. Variation in aphid performance was small but significant, with 15–25% fewer nymphs produced on plant variants that exhibited greater tissue water content and low tissue C:N ratio (A. fabae) or on variants with less phloem nitrogen (M. persicae). The differential responses exhibited by the two aphid species to the test accessions confirmed that quantifying intraspecific plant variation is a necessary first step in understanding plant functional diversity and its impact on consumers in arable systems.