扶桑绵粉蚧与长角立毛蚁的互惠关系及其对寄主棉花叶片叶绿素荧光特性的影响

Mutualistic interaction between Phenacoccus solenopsis and tending ant Paratrechina longcornis and their effects on chlorophyll fluorescence in cotton leaves

【背景】草食动物对寄主植物的取食或损伤会诱导改变植物的光合作用,从而直接影响植株的健康生长。产蜜昆虫与蚂蚁的互惠关系是物种相互促进的一种重要的生态学现象,能够促进产蜜昆虫的种群数量,然而这种互惠关系及其对寄主植物光合生理的影响还知之甚少。【方法】在室内条件下,运用叶绿素荧光动力学技术研究了外来入侵害虫扶桑绵粉蚧与长角立毛蚁的互惠对寄主棉花叶片叶绿素荧光特性的影响。【结果】随着扶桑绵粉蚧危害时间的延续,寄主植物上蚂蚁和扶桑绵粉蚧的数量均呈现显著上升的趋势,而在危害后期,蚂蚁存在情况下扶桑绵粉蚧的数量要明显低于无蚂蚁处理;在扶桑绵粉蚧取食寄主棉花20 d后,有、无蚂蚁存在的棉花叶片的光合利用率α值较无虫处理分别下降了53.5%和37.0%;存在蚂蚁或扶桑绵粉蚧危害后期对棉花叶片最大相对电子传递效率r ETRmax有显著影响,然而扶桑绵粉蚧单独取食或与蚂蚁互作的情况下未显著影响棉花叶片对强光的耐受能力(Ek)。【结论与意义】研究明确了扶桑绵粉蚧与长角立毛蚁的互惠关系对寄主棉花叶片的光合生理产生了一定的负面效应,为进一步解释扶桑绵粉蚧入侵、扩散及暴发的生态学过程提供了科学依据。

[Background] Herbivore injury has a direct effect on the growth and performance of host plants through photosynthetic suppression.However, changes in the photosynthetic activity of host plants affected by mutualism between honeydew-producing he-mipterans and tending ants remain poorly understood.[Method] The effects of interaction between an invasive mealybug Phenacoccus solen opsis and its tending ant Paratrechina longicornis on chlorophyll characteristics of infested cotton Gossypui m hirsutum leaves were observed through a chlorophyll fluorescence measurement system under greenhouse conditions.[Result]P .logn icornis numbers in-creased with P.solenopsis numbers.However, over time, plants infested with had a lower number of mealybugs than uninfested plants.Changes in light utilization efficiency were induced by P.solenopsis feeding of infested cotton leaves.After P.solenpo sis feeding injury for 20 d, the light utilization efficiency compared with the control was reduced by 37.0%and 53.5%for without-and with-ant treatments, respectively.Changes in maximum relative electron transport rate were also induced by P.solenopsis feeding injury, and the influence was more obvious after 20 d or with tending ant infestation.However, the light saturation coefficient describing the re-sistant capacity of a sample to glare was not influenced by P.solenopsis with or without ants.[Conclusion and significance] The inter-actions between P.solenopsis and P.longicornis and their negative effects on the photosynthetic activity of cotton leaves could have been caused by P.solenopsis feeding rate by P.longicornis.