Hwangbo Jun-Kwon, Seel Wendy E, Woodin Sarah J
School of Biological Sciences, Department of Plant and Soil Science, University of Aberdeen, Aberdeen AB24 3UU, UK.
J Exp Bot. 2003 Aug;54(389):1951-5. doi: 10.1093/jxb/erg194. Epub 2003 Jul 1.
The effects of elevated CO2 (650 ppm) on interactions between a chlorophyllous parasitic angiosperm, Rhinanthus minor (L.) and a host, Poa pratensis (L.) were investigated. R. minor benefited from elevated CO2, with both photosynthesis and biomass increasing, and transpiration and tissue N concentration remaining unaffected. However, this did not alleviate the negative effect of the parasite on the host; R. minor reduced host photosynthesis, transpiration, leaf area and biomass, irrespective of CO2 concentration. Elevated CO2 resulted in increased host photosynthesis, but there was no concomitant increase in biomass and foliar N decreased. It appears that the parasite may reduce host growth more by competition for nitrogen than for carbon. Contrary to expectation, R. minor did not reduce the productivity of the host-parasite association, and it actually contributed to the stimulation of productivity of the association by elevated CO2.
研究了高浓度二氧化碳（650 ppm）对一种含叶绿素的寄生被子植物小鼻花（Rhinanthus minor (L.)）与寄主草地早熟禾（Poa pratensis (L.)）之间相互作用的影响。小鼻花受益于高浓度二氧化碳，光合作用和生物量均增加，而蒸腾作用和组织氮浓度未受影响。然而，这并未减轻寄生植物对寄主的负面影响；无论二氧化碳浓度如何，小鼻花都降低了寄主的光合作用、蒸腾作用、叶面积和生物量。高浓度二氧化碳导致寄主光合作用增强，但生物量并未随之增加，且叶片氮含量降低。看来，寄生植物对寄主生长的抑制作用，氮竞争比碳竞争更为显著。与预期相反，小鼻花并未降低寄主 - 寄生植物组合的生产力，实际上它通过高浓度二氧化碳促进了该组合的生产力。
