In order to investigate the effect of potassium on the growth ofKostelezkya virginica under salt stress and the optimal potassium level,K. virginica seedlings were supplied with 1, 3, 6, 9, 12 and 15 mmol·L-1 potas-sium fertilizers under 0, 100 and 200 mmol·L-1 NaCl conditions. Then the parameters of the seedlings including growth conditions, photosynthetic gas exchange, chlorophyll alfuorescence dynamics, ion accumulation and plant injury indices were determined. Results show that the growth of the seedlings was inhibited by 100 mmol·L-1NaCl and, even more seriously, by 200 mmol·L-1 NaCl. With the increase of NaCl stress, Na+ content increased and K+ content went down obviously. Furthermore, with the increase of potassium level, Na+/K+ ratio decreased, meanwhile the plant height, dry and wet weights, plant total leaf area, the net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), maximal photochemical efifciency (Fv/Fm) and actual photochemical efifciency (ΦPSII) all increased obviously. The study also found that the optimal potassium level forK. virginica was 6–9 mmol·L-1 under control, while 9–12 mmol·L-1 under NaCl stress, suggesting that the demand ofK. virginica for potassium increases under salt stress and appropriate increase of potassium concen-tration can alleviate salt injury.
NETL
NSTL
万方数据
维普
