入侵种加拿大蓬对玉米的化感潜力及机制研究

Allelopathic Potential and Mechanism of Erigeron canadensis on Maize

采用盆栽法研究了入侵杂草加拿大蓬Erigeron canadensis L.对玉米Zea mays L.成熟植株的化感作用,并对其作用机制进行了探讨.结果发现,经加拿大蓬水提液处理后,玉米植株有矮化、弱化的趋势,生物量积累受阻,单株减产可达27.46%.分析玉米叶片的结构参数和气体交换参数发现,受试玉米叶面积减小12.58%以上,叶绿素a含量显著降低且与对照差异达显著水平;吐丝期、灌浆期净光合速率明显下降,其变化趋势与蒸腾速率、气孔导度一致,说明水汽、CO2进出气孔受阻是导致净光合速率降低的主要原因.而影响受体的光合作用是加拿大蓬水提液对玉米产生化感作用的一种重要途径.

The pot experiments were conducted to study the effect of exotic invasive plant Erigeron canadensis L. on mature plants of maize, Zea mays L. The result showed that the plant height, stem diameterand the dry matter accumulation in-roots, stems, leaves and corncob were reduced in the plants treated with aqueous leachates of E. canadensis, and the decrease in grain mass per plant was down to 27.46%.Leaf area of maize decreased by 12. 58%. The content of chlorophyll had a significant difference compared with the control. At silking and filling stages of corn, the net photosynthetic rate declined signifiantly, which was consistent with the change of transpiration rate and stomatal conductance, which suggested that the diffusion obstruction of CO2 or vapor in plant stomata was the main reason for decrease innet photosynthetic rate, and affecting photosythetic capacity of maize was an important mechanism of the aqueous leachates of E. canadensis.