烟草在PVY~N病毒与烟蚜作用下对高CO_2浓度的响应

以CO2浓度为主处理因子,研究了加倍CO2浓度和对照大气CO2浓度条件下,烟蚜、马铃薯Y病毒N株(PVYN)以及二者共同作用下烟草各指标的响应。结果表明,在当前CO2浓度条件下,PVYN、烟蚜及两者联合作用对烟草生物量影响不显著;而在未来高CO2浓度条件下,PVYN、烟蚜及两者联合作用对烟草生物量影响很大。CO2浓度升高后,PVYN和蚜虫二者联合作用显著降低烟草产量,危害加重,高CO2的"肥料"作用被极大地削弱。在有烟蚜、PVYN以及两者共同作用时烟草的化学物质及主要的次生代谢物烟碱的含量对CO2浓度升高的响应也发生一定的变化,表现在:高CO2浓度条件下,蚜虫、蚜虫与PVYN共同作用显著增加了烟草的含氮量;显著减少了烟叶含糖量;PVYN及其与蚜虫共同作用显著升高叶片可溶性蛋白含量;当高CO2浓度下,各处理的烟草烟碱含量均显著下降,而且PVYN感染的烟叶烟碱含量无论在哪一种CO2浓度条件下,都比无毒无虫的对照烟叶烟碱含量升高。结果显示,烟蚜和马铃薯Y病毒N株(PVYN)对烟草的产量、营养物质及防御物质都有影响;CO2浓度升高对烟草的生长有促进作用,增加了烟草的产量,但蚜虫的危害和PVYN感染使烟草产量下降,在高CO2浓度条件下,烟蚜和PVYN共同作用相对于目前CO2浓度对烟草产量的危害加重。

Responses of tobacco associated with PVYN and tobacco aphid to elevated CO2 concentration

Atmospheric CO2 concentration has been proved to be increased in the future. In this study, responses of tobacco plants to stress from the tobacco aphid, Myzus persicae (Sulzer) or PVYN (potato virus Y), or stresses from both aphid and PVYN combined were investigated in OTC (open-top chambers) under ambient and elevated CO2 concentrations. We experimentally examined aboveground biomass and foliar chlorophyll, nitrogen, non-structural carbohydrates, soluble protein, total amino acid and nicotine content in tobacco plants under elevated CO2. The increase of tobacco biomass was alleviated after infected by PVYN and aphid under elevated CO2, while no significant difference of tobacco biomass was found under ambient CO2. Significant higher nitrogen content after infected with virus or by aphid + virus and soluble protein content of tobacco after infested by aphid or by aphid+virus occurred in elevated CO2. Moreover, significant higher nicotine content was observed in the tobacco with PVYN-infection in comparison with tobacco with aphids under two CO2 treatments. Our results indicated that both PVYN and tobacco aphid are major factors influencing tobacco yield and constitution significantly. The significant lower biomass of tobacco after infested by PVYN + aphid under elevated CO2 suggested that inhibition of PVYN and aphid together on tobacco growth would be stronger in future elevated CO2.Under elevated CO2 condition, both PVYN and tobacco aphid would continue to play adverse role in tobacco production. Moreover, higher CO2 concentration would strengthen the negative effects of the two integral agricultural factors.