CO2浓度倍增条件下泽兰实蝇寄生对紫茎泽兰生长和营养成分的影响

摘要

The growth and nutrition of Ageratina adenophora were measured under two CO 2concentrations (400 μL/L VS 800 μL/L)with presence and absence of its natural enemy, Procecidochares utilis.The results showed that the growth of A.adenophora was inhibited with P.utilis parasitism under both CO 2 concentrations,while there were differences with regard to the height, stem diameter, internodal distance and nutrient contents of A.adenophora between two CO2concentrations.With the same parasitic intensity, the height, internodal distance and stem diameter of A.adenophora under 800 μL/L CO2concentration increased 31.74%, 6.70% and 9.84%, respectively, comparing with those of A.adenophora planting under 400 μL/L CO2concentration.Parasitism of P.utilis under 800 μL/L CO2concentration might lead to significantly decrease of free amino acids and starch content of A.adenophora(P<0.01).The number of galls and F1emergence of P.utilis adults under 800 μL/L CO2concentration were significantly lower than those of P.utilis adults under 400 μL/L CO2concentration.The results indicated that the inhibitory effect of P.utilis on A.adenophora might be weakened under the doubled CO 2concentration, which would provide theoretical evidence for predicting the control capability of P.utilis parasitism on A.adenophora under the changing global climate.%利用人工气候箱设置两种CO2浓度(400 μL/L和800 μL/L),在释放和未释放天敌泽兰实蝇两种情况下测定了紫茎泽兰的生长状况和营养成分.结果表明,在两种CO2浓度下泽兰实蝇的寄生均可抑制紫茎泽兰的生长,但不同CO2浓度下生长的紫茎泽兰株高、茎直径、节间距和各营养成分含量存在差异.在相同的寄生强度下, 800 μL/L CO2浓度下生长的紫茎泽兰比400 μL/L CO2浓度下生长的紫茎泽兰的株高、节间距和茎直径分别增加了31.74%、6.70%和9.84%; CO2浓度倍增条件下泽兰实蝇的寄生导致紫茎泽兰的游离氨基酸和淀粉含量显著降低(P<0.01),分别较对照降低了25.81%和11.76%;在800 μL/L CO2浓度下紫茎泽兰形成的虫瘿和羽化出下一代泽兰实蝇的数量也显著低于400 μL/L CO2浓度下的处理植株,说明CO2浓度倍增条件下泽兰实蝇对紫茎泽兰的抑制效果减弱.研究结果可为预测全球气候变化下泽兰实蝇对紫茎泽兰的控制效应提供理论依据.