Meeting Abstract
73.7 Sunday, Jan. 6 Life-history and physiological strategies of the grain aphid and its invasion to Chile CASTA�EDA , Luis E.*; FILUN, Marcela; FUENTES-CONTRERAS, Eduardo; NIEMEYER, Hermann M.; FIGUEROA, Christian C.; NESPOLO, Roberto F.; Universidad Austral de Chile; Universidad Austral de Chile; Universidad de Talca; Universidad de Chile; Universidad Austral de Chile; Universidad Austral de Chile luiscastaneda@uach.cl
Plant allelochemicals, such as hydroxamic acids (Hx) from cereals, had been proposed as important selective agents to phytophagous insect populations, configuring a patchy chemically environment at local spatial scale. In cereal aphids, several enzymes have been associated to detoxification of Hx, showing differential activities depending on the host species and cultivar. Aphids from three highly ecologically successful genotypes of Sitobion avenae (Sa1, Sa2 and 46) were reared on low, medium and high-Hx wheat cultivars. To evaluate if S. avenae shows a genotype-environment interaction (GxE) related to host plant chemistry, the physiological capacities of each genotype reared on each cultivar was determined by measuring the metabolic rate and the activities of mixed-function oxidases (MFO), gluthation S-transferases (GST), and esterases (EST). Simultaneously, the fitness of each genotype on each cultivar was assessed through life-history traits (i.e. offspring size, developmental time and intrinsic growth rate). Our results suggest a significant genetic variability and a minor effect of host chemistry, which mostly affects MFO activity in Sa46 and an increment in intrinsic growth rate on medium-Hx cultivar. In general, we did not find that GxE was an important factor shaping the genetic architecture of S. avenae. Instead, our results suggest that those successful biotypes of S. avenae are multi-purpose genotypes able to use a broad host range, showing a low variance in their performances on hosts with different Hx levels. Funded by CONICYT AT-24060132 and PBCT-Anillos ACT38.
