Effect of salt stress on the growth and photosystem II photochemical characteristics of Lycium ruthenicum Murr. seedlings

Abstract

The present study aimed to determine effects of salt stress on Lycium ruthenicum Murr. seedlings. Our results showed that mild and moderate salt stress were beneficial to L. ruthenicum seedling growth. Minimal fluorescence increased and maximum fluorescence decreased gradually with the increasing levels of salt stress. Absorption flux per reaction center (RC), trapped energy flux per RC, and trapped energy flux per optical cross section (CS) increased significantly, while electron transport flux per CS decreased with salt stress duration and rising salt concentration. During salt stress, there was a gradual decline in probability that a trapped exciton moves an electron into the trapped electron transport chain beyond QA, quantum yield for electron transport, and performance index on absorption basis. However, gradual increases in relative variable fluorescence, dissipated energy flux per RC, and dissipated energy flux per CS were found in response to salt stress.

Keywords

• chlorophyll fluorescence kinetics; ojip transient; photosynthesis; salt tolerance.