Effects of elevated CO2 and plant genotype on interactions among cotton, aphids and parasitoids

• Published in: Insect science 2011-08, Vol.18 (4), p.451-461
• Main Authors: Sun, Yu-Cheng, Feng, Li, Gao, Feng, Ge, Feng
• Format: Article
• Language: English
• Subjects: Abundance; Aphididae; Aphis gossypii; Carbohydrates; Carbon dioxide; cotton; cotton genotype; Crops; elevated CO2; Fitness; genotype; genotype-environment interaction; Genotypes; Gossypium hirsutum; Gossypol; Hymenoptera; Lysiphlebia; Lysiphlebia japonica; Nitrogen; Parasitism; Parasitoids; Pest status; proanthocyanidins; Tannic acid; tritrophic interaction; 二氧化碳浓度升高; 基因型; 大气; 寄生蜂; 棉花; 棉蚜虫; 植物; 相互作用
• ISSN: 1672-9609; 1744-7917
• DOI: 10.1111/j.1744-7917.2010.01328.x

Abstract Effects of CO₂ level (ambient vs. elevated) on the interactions among three cotton (Gossypium hirsutum) genotypes, the cotton aphid (Aphis gossypii Glover), and its hymenoptera parasitoid (Lysiphlebia japonica Ashrnead) were quantified. It was hypothesized that aphid-parasitoid interactions in crop systems may be altered by elevated CO₂, and that the degree of change is influenced by plant genotype. The cotton genotypes had high (M9101), medium (HZ401) and low (ZMS13) gossypol contents, and the response to elevated CO₂ was genotype-specific. Elevated CO₂ increased the ratio of total non-structural carbohydrates to nitrogen (TNC: N) in the high-gossypol genotype and the medium-gossypol genotype. For all three genotypes, elevated CO₂ had no effect on concentrations of gossypol and condensed tannins. A. gossypii fitness declined when aphids were reared on the high-gossypol genotype versus the low-gossypol genotype under elevated CO₂. Furthermore, elevated CO₂ decreased the developmental time of L. japonica associated with the high-gossypol genotype and the low-gossypol genotype, but did not affect parasitism or emergence rates. Our study suggests that the abundance of A. gossypii on cotton will not be directly affected by increases in atmospheric CO₂. We speculate that A. gossypii may diminish in pest status in elevated CO₂ and high-gossypol genotype environments because of reduced fitness to the high-gossypol genotype and shorter developmental time of L. japonica.