采用溶液培养的方法,研究了镉(Cd)和脱落酸(ABA)对不结球白菜幼苗生长以及Cd积累的影响。结果表明,10μmol·L-1Cd处理显著抑制不结球白菜幼苗的干物质积累,降低不结球白菜叶片的净光合速率、蒸腾速率、气孔导度、PSⅡ最大光化学效率、PSⅡ光合电子传递量子效率、电子传递速率和光化学猝灭系数,增加不结球白菜叶片的非光化学猝灭系数。5μmol·L-1ABA处理对不结球白菜地上部干物质的积累及净光合速率没有显著影响,但降低了不结球白菜的根系干重、叶片的蒸腾速率和气孔导度。而在100μmol·L-1Cd胁迫下,外源ABA处理明显增加不结球白菜根系Cd含量,降低Cd向地上部的转运能力,降低不结球白菜地上部Cd含量。试验结果还显示:不结球白菜地上部Cd含量占总Cd含量的百分比与叶片蒸腾速率呈显著正相关。
Hydroponic methods were used to study the effect of cadmium(Cd)and abscisic acid(ABA)on growth and Cd accumulation of Brassica campestris ssp.chinensis L.seedlings.Results indicated that 10 μmol·L-1 Cd significantly inhibited the dry weight accumulation of B.campestris ssp.chinensis,reduced net photosynthetic rate,transpiration rate,stomatal conductance,Fv/Fm,φPSⅡ,ETR and qP of leaf,and increased qN.Treatment with 5 μmol·L-1 ABA had no effect on shoot dry weight accumulation and net photosynthetic rate,but reduced root dry weight,leaf transpiration rate and stomatal conductance.In the presence of 100 μmol·L-1 Cd,exogenous ABA treatments increased the concentration of Cd in the roots,reduced the transport of Cd to the shoot from root and Cd concentration in shoot.The percentage of shoot/total Cd content showed a significant relationship with the transpiration rate.