棉花对大气CO_2浓度升高的响应及其对棉蚜种群发生的作用

Responses of cotton to elevated CO_2 and the effects on cotton aphid occurrences

通过模拟试验研究了棉花对大气 CO2 浓度升高 (70 5 .0 μl/ L 和 10 32 .3μl/ L vs.387.4 μl/ L)的响应及其对棉蚜 (Aphisgossypii Glover)种群发生的作用机制。结果表明 :(1) CO2 浓度升高可以促进棉花的生长 ,显著提高棉花的株高和生物产量 ;(2 )CO2 浓度增加对棉花的光合作用十分有利 ,单株叶面积显著增加 ,同时 ,叶绿素含量也显著增加 ;(3)高的 CO2 浓度可明显影响棉花组织的营养成分和次生代谢物质的含量 ,游离脂肪酸和游离氨基酸显著增加 ,可溶性蛋白含量显著降低 ,此外 ,大气 CO2增加下棉花组织内棉酚和单宁含量也显著增加了 ;(4 )棉蚜的发育历期与棉花组织的游离脂肪酸、游离氨基酸、可溶性蛋白、和棉酚的含量呈显著负相关 ;而棉蚜的繁殖力与组织含水量呈显著负相关 ,与游离脂肪酸、游离氨基酸和棉酚的含量呈显著正相关。大气 CO2 浓度升高主要是通过影响棉花的营养组成和次生代谢物质含量 ,而间接作用于棉蚜 ;未来 ,随着大气 CO2 浓度增加 。

Responses of cotton to elevated CO_2 (705.0 μl/L and 1032.3 μl/L vs. 387.4 μl/L.) and the effects on the occurrence of Aphis gossypii Glover were researched during cotton-seedling stage by simulated experiments in climate chambers. Our results indicated that: (1) Elevated CO_2 concentrations at 705.0 μl/L and 1032.3 μl/L promoted plant growth with significant increases in plant height and biomass. (2) It was very advantageous for the photosynthesis of cotton plant in elevated CO_2, and significant increases were observed in leaf area, leaf area ratio and chlorophyll content. (3) Elevated CO_2 significantly enhanced the contents of free fatty acids, free amino acids, tannins and gossypol of cotton plants, but significantly reduced soluble protein contents. (4) Significantly negative correlation was observed between life-span of aphid and some chemical components of host cotton plant, i.e. free fatty acids, free amino acids, soluble protein and gossypol of cotton plants grown in climate chambers at different levels of CO_2 concentrations. Moreover, free fatty acids, free amino acids and gossypol (%) all had significantly positive correlation with fecundity of aphid, and the correlation between fecundity and water (%) was significantly negative. So, elevated CO_2 indirectly impacted aphid populations by changing the chemical component contents of host cotton seedlings. Furthermore, it is beneficial for cotton growth that the atmospheric CO_2 concentration increases in the future, but, simultaneously, the occurrence of aphid A. gossypii will become severer.