关键词: 豌豆蚜, CO2浓度升高, 蚕豆, 营养物质, 消化酶

Abstract: 【Aim】 To clarify the physiological mechanisms of the red and green color morphs of the pea aphid, Acyrthosiphon pisum (Harris), in response to elevated CO₂ concentration. 【Methods】 Two elevated levels of CO₂ concentration (moderate: 550±27 μL/L; doubling: 750±37 μL/L) were manipulated in incubators with ambient CO₂ (375±18 μL/L) as the control. Vicia faba seedlings were planted in the above incubators, nymphs of the pea aphid within 6 h were introduced later, and molting and the survival in various developmental stages were recorded until the adult. Nutrient contents and digestive enzyme activities of two color (red and green) morphs of the pea aphid in three successive generations and nutrient contents in V. faba leaves were assayed. 【Results】 Elevated CO₂ concentration significantly enhanced the contents of soluble protein, soluble carbohydrates, free amino acids and starch in V. faba leaves. Under the moderate CO₂ concentration (550±27 μL/L) condition, the nutrient contents in F₀ generation of the two color morphs of the pea aphid had no significant difference as compared with the control, while the contents of protein, total amino acids, soluble carbohydrates and glycogen in F₂ generation all increased and the contents of total lipid and free fatty acids decreased significantly, and moreover the content of soluble carbohydrates in F₂ generation of green pea aphid was significantly higher than that in red pea aphid. Under the doubling CO₂ concentration (750±37 μL/L) condition, the contents of protein, total amino acids, soluble carbohydrates and glycogen in three successive generations of the two color morphs all increased significantly and the contents of total lipid and free fatty acids decreased significantly as compared with the control, and moreover the contents of protein, total amino acids, and glycogen in the F₁ and F₂ generations of green pea aphid were significantly higher than those in red pea aphid. Under the elevated CO₂ concentration (550±27 and 750±37 μL/L) conditions, the digestive enzyme activities in F₀ generation of two color morphs of the pea aphid had no significant difference as compared with the control, while the pepsin and trypsin activities in F₂ generation decreased significantly and those of lipase and amylase increased significantly, and moreover the digestive enzyme activities had no significant difference between the two color morphs.【Conclusion】 Under the elevated CO₂ concentration, the change in nutrient composition in broad bean leaf causes the change in nutrient composition and digestive enzyme activities in pea aphids feeding the disposed V. faba leaves. Additionally, the changes in contents of protein, total amino acids, soluble carbohydrates and glycogen in the green morph of the pea aphid are more significant than those in the red morph. These results provide some references for controlling the pea aphid, the main pest in leguminous plants, under the elevated atmospheric CO₂ concentration condition in the future.

Key words: Acyrthosiphon pisum, elevated CO₂ concentration, Vicia faba, nutrient, digestive enzyme