Effect of saline-alkali stress on the growth and related physiological indicators of ‘Cabernet Sauvignon’ grape seedlings

Abstract

Abstract [Objective] The study aims to understand the effects of the combined saline and alkaline stress with different salt distribution ratios and different concentration gradients on the growth and physiological indexes of ‘Cabernet Sauvignon’ grape (Vitis vinifera ‘Cabernet Sauvignon’) seedlings, and confirm the range of salinity tolerance and its ability to tolerate salinity. [Methods] One-year-old ‘Cabernet Sauvignon’ seedlings were used as test materials. Three groups, including neutral, weak alkaline, and strong alkaline salt solutions, were mixed with NaCl, Na2SO4, NaHCO3, and Na2CO3 in different ratios, with a concentration gradient of 50, 100, and 150 mmol/L, and with no treatment solution as control. The seedlings were watered regularly during the growth period. Different types and degrees of saline and alkaline stress were simulated with pot experiments in the lab, and the growth morphology, physiology and photosynthetic indexes were measured. [Results] (1) Stem diameter and leaf area of ‘Cabernet Sauvignon’ seedlings was increased first and then decreased with the increase in salt concentration, while plant height showed a decreasing trend. Plant height was significantly lower at 150 mmol/L for 10 days and 40 days for the strong alkaline group compared with the neutral and weak alkaline groups. (2) SOD activity and MDA content in the leaves of ‘Cabernet Sauvignon’ seedling was increased first and then decreased with the increase in salt concentration, while POD activity was increased slowly. The POD activity of leaves in the strong alkaline salt stress group was higher than that of the neutral and weak alkaline salt stress group for 30-50 days, while the strong group was lower than the neutral and weak groups for 60 days, where 150 mmol/L treatment was more obvious. (3) Intercellular CO2 concentration, net photosynthetic rate and transpiration rate of ‘Cabernet Sauvignon’ seedlings showed a decreasing trend with the increase in salinity concentration, and their intercellular CO2 concentration and net photosynthetic rate were higher at 50 mmol/L. Under same salt treatment, the net photosynthetic rate in leaves of neutral and weak alkaline groups were lower than the strong group at 150 mmol/L for 75 days. [Conclusion] The plant height, leaf area, intercellular CO2 concentration, net photosynthetic rate and transpiration rate of ‘Cabernet Sauvignon’ seedlings showed a good growth trend at 50 mmol/L, while plant height and stem diameter was the least obvious at 150 mmol/L saline solution for the strong alkaline salt stress; low saline treatment (50 mmol/L) was favorable to the growth of ‘Cabernet Sauvignon’ seedlings.

Keywords

• ‘cabernet sauvignon’ grape
• saline-alkali stress
• physical and chemical properties
• eastern foothills of helan mountain