Kentucky bluegrass ( Poa pratensis L.) silicon-treated turfgrass tolerance to short- and long-term salinity condition

Abstract

The effects of short- and long-term salinity condition were investigated on silicon-treated and control plants of Kentucky bluegrass (KBG) (Poa pratensis L.) in a greenhouse study. Salt stress solely affected visual quality at ≥15 dS m-1 concentrations while Si application increased salt tolerance of KBG after 45 days. In long-term salinity stress, Si had no effect on salt tolerance of KBG at ≥15 dS m-1 concentration. Si increased morphological parameters including height and number of shoots, and physiological parameters including relative water content (RWC) and chlorophyll content of leaves. In addition, fresh and dry weights of roots and shoots in response to high salt concentrations declined, but showed an increase with Si treatment. Proline content and electrolyte leakage (EL) increased under high salinity levels. In response to the Si treatment, Na concentration in the shoots significantly decreased at the 5 dS m-1 salinity level. With increasing salinity levels, the concentration of K in roots and shoots decreased while the amount of K in both Si-treated roots and shoots reduced. Overall, Si alleviative effects were more pronounced in 45 days after turfgrasses being salinity treated.