Effects of genotype, nutrient availability, and defoliation on aspen phytochemistry and insect performance

Citation
Tl. Osier et Rl. Lindroth, Effects of genotype, nutrient availability, and defoliation on aspen phytochemistry and insect performance, J CHEM ECOL, 27(7), 2001, pp. 1289-1313
Citations number
76
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
JOURNAL OF CHEMICAL ECOLOGY
ISSN journal
0098-0331 → ACNP
Volume
27
Issue
7
Year of publication
2001
Pages
1289 - 1313
Database
ISI
SICI code
0098-0331(200107)27:7<1289:EOGNAA>2.0.ZU;2-2
Abstract
Genetic and environmental variability. and their interactions, influence ph ytochemical composition and, in turn, herbivore performance. We evaluated t he independent and interactive effects of plant genotype, nutrient availabi lity, and defoliation on the foliar chemistry of quaking aspen (Populus tre muloides) and consequences for performance of gypsy moths (Lymantria dispar ). Saplings of four genotypes were grown under two conditions of nutrient a vailability and subjected to three levels of artificial defoliation. Concen trations of all secondary and primary metabolites evaluated responded to at least one or more of the experimental treatments. Of the secondary metabol ites, phenolic glycosides were affected strongly by genotype, less so by nu trient availability, and not induced by defoliation. Condensed tannins were strongly dependent upon genotype, soil nutrient availability, and their in teraction, and, in contrast to phenolic glycosides, were induced by artific ial defoliation. Of the primary metabolites, foliar nitrogen was affected b y genotype and soil nutrient availability. Starch concentrations were affec ted by genotype, nutrient availability, defoliation and interactions among these factors. Foliar water content responded to genotype, nutrient availab ility, and defoliation, and the effect of nutrient availability depended on genotype. Herbivore performance on these plants was strongly influenced by plant genotype and soil nutrient availability, but much less so by defolia tion. Although several of the compound types (condensed tannins, starch, an d water) responded to defoliation, quantitative variation in these compound s did not contribute to substantive changes in herbivore performance. Rathe r, the primary source of variation in insect performance was due to plant g enotype (phenolic glycoside levels), while nutrient availability (foliar ni trogen levels) was of secondary importance, These results suggest that gene tic variation in aspen plays a major role in determining patterns of insect performance, whereas environmental variation, such as was tested, here is of negligible importance.