不同磷水平下外接AMF对三叶鬼针草和金盏银盘形态指标及光合生理的影响

Effects of AMF on Morphological Index and Photosynthetic Physiology of Bidens pilosa and B.biternata under Different Phosphorus Levels

为探究不同磷水平下丛枝菌根真菌(Arbuscular mycorrhiza fungi,AMF)对入侵植物三叶鬼针草(Bidens pilosa)和四川本地近缘植物金盏银盘(B. biternata)生长状况、营养吸收、光合作用以及抗氧化酶活性的影响,设0、50、200 mg/kg磷水平下对2种植物接种AMF摩西斗管囊霉(Funneliformis mosseae)以及不接种对照(CK)盆栽试验。结果表明,AMF均能侵染上述2种植物,且AMF对三叶鬼针草的侵染率和孢子密度均显著高于金盏银盘,在50 mg/kg磷水平下三叶鬼针草的侵染率和孢子密度最高。0、50mg/kg磷水平下接种AMF处理均可以显著促进2种植物对磷的吸收,对氮的吸收下降;对2种植物的株高、叶面积、总生物量、分枝数和根冠比也有一定的促进作用。50 mg/kg磷水平下,与CK相比,接种AMF的三叶鬼针草和金盏银盘总叶绿素含量、叶绿素a/b、最大荧光、PSⅡ最大光化学量子产量以及光合性能指数分别增加22.1%~22.9%、8.4%~11.5%、15.5%~23.8%、11.4%~14.4%、17.9%~25.9%;净光合速率、气孔导度和蒸腾速率分别增加8.1%~17.7%、18.4%~18.7%、12.6%~14.9%,胞间CO_(2)浓度下降9.4%~14.7%;超氧化物歧化酶、过氧化氢酶、过氧化物酶活性显著高于CK,分别提高了17.2%~19.3%、37.4%~46.4%、24.1%~32.1%;渗透调节物质可溶性糖、可溶性蛋白含量分别提高了45.6%~59.8%、33.3%~45.1%。综上,低磷水平(0、50 mg/kg)下AMF能够促进三叶鬼针草和金盏银盘的生长,且三叶鬼针草的菌根效应高于金盏银盘,高磷(200 mg/kg)水平整体上对2种植物生长产生一定抑制,菌根效应很可能对低磷环境下三叶鬼针草的成功入侵产生一定的作用。

A pot experiment was conducted to investigate the effects of arbuscular mycorrhizal fungi(AMF)on the growth status,nutrient absorption,photosynthesis,and antioxidant enzyme activity of invasive plant Bidens pilosa and local closely related plant B.biternata under different phosphorus levels of 0,50,and 200 mg/kg,inoculated with Funneliformis mosseae on two plants and with no inoculation as control(CK).The results showed that AMF could infect both plants mentioned above,and the infection rate and spore density of AMF on B.pilosa were significantly higher than those on B.biternata.At a phosphorus level of 50 mg/kg,B.pilosa had the highest infection rate and spore density.Inoculation of AMF at 0 and 50 mg/kg phosphorus concentration could significantly promote the absorption of phosphorus by both plants,while the absorption of nitrogen decreased.It also had a certain promoting effect on the plant height,leaf area,total biomass,number of branches,and root crown ratio of both plants.At a phosphorus level of 50 mg/kg,compared with CK,the total chlorophyll content,chlorophyll a/b,maximum fluorescence,maximum photochemical quantum yield of PSⅡ,and photosynthetic performance index of B.pilosa and B.biternata inoculated with AMF increased by 22.1%—22.9%,8.4%—11.5%,15.5%—23.8%,11.4%—14.4%,and 17.9%—25.9%,respectively.The net photosynthetic rate,stomatal conductance,and transpiration rate increased by 8.1%—17.7%,18.4%—18.7%,and 12.6%—14.9%,respectively,while the intercellular CO2 concentration decreased by 9.4%—14.7%.The activities of superoxide dismutase,catalase,and peroxidase treated with AMF were significantly higher than those of CK,with increases of 17.2%—19.3%,37.4%—46.4%,and 24.1%—32.1%,respectively.The contents of soluble sugar and soluble protein in osmotic regulators were increased by 45.6%—59.8%and 33.3%—45.1%,respectively.In summary,AMF can promote the growth of B.pilosa and B.biternata under low phosphorus levels(0,50 mg/kg),and the mycorrhizal effect of B.pilosa is higher than that of B.biternata,while the high phosphorus level(200 mg/kg)has a certain inhibitory effect on the growth of the two plants,which is likely to have a certain effect on the successful invasion of B.pilosa in a low phosphorus environment.