土壤铅污染对糜子生长和光合生理特征的影响

Effects of Soil Pb Pollution on the Growth and Photosynthetic Characteristics of Proso Millet(Panicum miliaceum L.)

为探讨土壤铅污染对新疆糜子(Panicum miliaceum L.)生长和光合生理特征的影响,以塔城糜子(收藏号:XJAU-MZ-005)、木垒黄糜(收藏号:XJAU-MZ-076)和吉木萨尔黄糜(收藏号:XJAU-MZ-008)为材料,通过盆栽培养,研究不同浓度土壤铅(50、100、200 mg/kg)污染对糜子生长及光合生理特征的影响。结果表明,铅处理显著抑制塔城糜子的株高、生物量和SPAD值,但50 mg/kg Pb处理对木垒黄糜、吉木萨尔黄糜的株高和SPAD值无显著影响,并且50、100 mg/kg Pb处理显著促进了吉木萨尔黄糜的生物量。3种糜子的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、光能利用效率(Eu)和水分利用效率(WUE)均随着铅浓度的增大而降低,而胞间二氧化碳浓度(Ci)增大及净光合速率下降是由于非气孔因素造成。木垒黄糜和吉木萨尔黄糜在轻度铅污染土壤上的耐性较强,可考虑作为轻度铅污染土壤的绿化或修复植物。

In order to explore the effects of soil Pb pollution on growth and photosynthetic physiological characteristics of proso millet(Panicum miliaceum L.)in Xinjiang,the effects of different concentrations of soil Pb(50,100,200 mg/kg)pollution on growth and photosynthetic physiological characteristics of millet were studied by pot culture using Tacheng proso millet(Collection No.XJAU-MZ-005),Mori yellow proso millet(Collection No.XJAU-MZ-076)and Jimsar yellow proso millet(Collection No.XJAU-MZ-008)as materials.Pb significantly inhibited the Tacheng proso millet height,biomass and SPAD values,but the 50 mg/kg Pb treatment had no significant effect on the Mori and Jimsar yellow proso millet height and SPAD values,and 50,100 mg/kg Pb treatments significantly promoted the Jimsar yellow proso millet biomass.The net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),light utilization efficiency(Eu)and water use efficiency(WUE)of the three kinds of proso millet all decreased with the increase of Pb concentrations,while the intercellular carbon dioxide concentration(Ci)increased,and the decrease of net photosynthetic rate was caused by non-stomatal factors.In conclusion,Mori yellow proso millet and Jimsar yellow proso millet has strong tolerance on Pb polluted soil and can be considered as a remediation plant for soil with mild Pb contamination.