Response of Photosynthetic and Physiological Characteristics of Rubus idaeus L. Variety ‘Qiuping’ to NaCl and NaHCO₃ Single Salt Stress

PurposesTo study the adaptability of Rubus idaeus L. ‘Qiuping’ to stress conditions in saline-alkaline soil cultivation, so as to provide theoretical reference for orchard site selection and production.

MethodsThe tissue culture seedlings of Qiuping were used as materials, and after pot culture for a period of time, the single salt stress test was carried out with neutral salt (NaCl) and alkaline salt (NaHCO₃). Photosynthetic characteristics and physiological indexes were determined.

ResultsLow concentration (30-60 mmol/L) stress could promote the growth of Qiuping, mainly including the increase of net photosynthetic rate and stomatal conductance, the increase of pigment content, the decrease of leaf litter, and the decrease of SOD and POD activities. Under the medium concentration (90-120 mmol/L) stress, Qiuping could grow, but the photosynthesis was inhibited, showing physiological drought, stomatal conductance was decreased, CAT activity was increased, proline content was increased. Under the high concentration (150-180 mmol/L) stress, photosynthesis was strongly inhibited, leaf pigment was decreased, protective enzyme activity was decreased, osmotic regulatory substances were also decreased, and Qiuping died at 180 mmol/L NaCl.

ConclusionThe NaHCO₃ tolerance of Qiuping is stronger than that of NaCl, and it can adapt to saline-alkali environment with a large concentration range. Mild saline-alkali stress can promote the growth of Qiuping.