盐碱胁迫对赤霞珠葡萄幼苗生长及相关生理指标的影响

【目的】了解不同盐分配比和不同浓度梯度复合盐碱胁迫对‘赤霞珠’葡萄（Vitis vinfera ‘Cabernet Sauvignon’）幼苗生长和抗逆生理指标的影响，确认其耐盐碱性范围及其耐盐碱能力。【方法】 以1年生‘赤霞珠’自根苗为试材，用NaCl、Na2SO4、NaHCO3、Na2CO3按不同比例混合配置中性盐、弱碱性盐、强碱性盐3组复合盐溶液，每组各设置50、100、150 mmol/L3个浓度梯度，以不做处理的溶液作为对照，于幼苗生长期间进行定期浇灌处理，通过室内盆栽试验来模拟不同类型、不同程度盐碱胁迫，在处理后不同时期测定幼苗生长形态、生理及光合指标。【结果】（1）茎粗和叶面积随盐胁迫浓度增大，呈现先增大后减小的趋势， 而‘赤霞珠’幼苗的株高基本呈现下降趋势。其中，中性、弱碱性、强碱性盐胁迫组间相比，‘赤霞珠’幼苗株高在强碱性盐胁迫组150 mmol/L处理10 d、150 mmol/L处理40 d都较同期中性、弱碱性组相应浓度显著降低；（2）随着盐浓度的增大，SOD活性及MDA含量呈先增大后减小的趋势，而‘赤霞珠’幼苗叶片的POD活性呈现缓慢增加的趋势，强碱性盐胁迫组叶片POD活性在处理30-50d时均高于相同浓度的中性、弱碱性盐胁迫处理组，但随着时间处理延长，到处理60 d后逐渐低于同浓度其他两处理组，其中150 mmol/L浓度表现得更明显。；（3）‘赤霞珠’葡萄幼苗胞间CO2浓度、净光合速率、蒸腾速率随着盐碱浓度的增加主要呈下降趋势，其胞间CO2浓度与净光合速率均为50 mmol/L浓度处理时较高。在同期相同盐浓度处理下，叶片净光合速率在强碱性盐胁迫150 mmol/L浓度处理75 d时显著低于同期中性、弱碱性处理组。（4）在相同浓度条件下，强碱性盐胁迫处理的幼苗株高及最大叶面积都显著低于中性盐和弱碱性盐处理组；叶片SOD活性在50 mmol/L中性盐胁迫处理下较CK显著提高了27%；叶片MDA含量在150 mmol/L强碱性盐胁迫下随着时间延长显著逐渐增加。【结论】‘赤霞珠’幼苗生长在盐碱胁迫下受到一定限制，但其株高、叶面积、胞间CO2浓度、净光合速率、蒸腾速率在50 mmol/L浓度处理下均呈现较好的增长趋势，而其株高及茎粗在强碱性盐胁迫150 mmol/L盐碱溶液处理下均增长最不明显；在一定低浓度浓度范围内50 mmol/L盐碱处理有利于赤霞珠葡萄幼苗生长。

Effect of Salinity Stress on the Growth and Related Physiological Indicators of Cabernet Sauvignon Grape Seedlings

【Objective】To understand the effects of compound saline and alkaline stresses with different salt distribution ratios and different concentration gradients on the growth and physiological indexes of resistance of "Cabernet Sauvignon" grape (Vitis vinfera "Cabernet Sauvignon") seedlings. To confirm the range of salinity tolerance and its ability to tolerate salinity.【Methods】One-year-old Cabernet Sauvignon seedlings were used as test materials, and three groups of neutral, weakly alkaline, and strongly 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 for each group, and no treatment solution was used as control. The solution without treatment was used as the control, and the seedlings were watered regularly during the growth period. Different types and degrees of saline and alkaline stress were simulated through indoor potting experiments, and the growth morphology, physiology and photosynthetic indexes of the seedlings were measured at different periods after the treatment.【Results】1) Stem thickness and leaf area showed a tendency of increasing and then decreasing with the increase of salt stress concentration, while the plant height of "Cabernet Sauvignon" seedlings basically showed a decreasing trend. The plant height of "Cabernet Sauvignon" seedlings was significantly lower in the 150 mmol/L treatment for 10 d and 150 mmol/L treatment for 40 d in the strongly alkaline salt stress group compared with that in the neutral and weakly alkaline groups during the same period of time; 2) SOD activity and MDA content showed an increase and then a decrease with the increase of salt concentration. MDA content showed a trend of increasing and then decreasing, while the POD activity of "Cabernet Sauvignon" seedling leaves showed a trend of slow increase, the POD activity of leaves in the strongly alkaline salt stress group was higher than that of the neutral and weakly alkaline salt stress treatment group of the same concentration in the treatment of 30-50 d. However, with the prolongation of the time treatment, the POD activity of "Cabernet Sauvignon" seedlings was lower than that of the other two treatment groups of the same concentration in the treatment of 60 d, but with the prolongation of the time treatment, it gradually decreased. lower than the other two treatment groups with the same concentration, in which the 150 mmol/L concentration showed more obvious. 3) Intercellular CO2 concentration, net photosynthetic rate and transpiration rate of "Cabernet Sauvignon" grape seedlings mainly showed a decreasing trend with the increase of salinity concentration, and their intercellular CO2 concentration and net photosynthetic rate were higher in the treatment of 50 mmol/L concentration. Under the same salt concentration treatment, the net photosynthetic rate of leaves was significantly lower than that of neutral and weakly alkaline treatment groups under strong alkaline salt stress at 150 mmol/L for 75 d. The net photosynthetic rate of leaves was significantly lower than that of neutral and weakly alkaline treatment groups under the same salt concentration treatment. 4) Under the same salt concentration, the height and maximum leaf area of seedlings treated with strong alkaline salt stress were significantly lower than those of the neutral and weak alkaline salt treatment groups; the leaf SOD activity was significantly increased by 27% in the 50 mmol/L neutral salt stress treatment compared with that of the CK; and the MDA content of the leaves increased significantly and gradually with the prolongation of time under the 150 mmol/L strong alkaline salt stress.【Conclusion】The growth of "Cabernet Sauvignon" seedlings was limited under saline stress, but its plant height, leaf area, intercellular CO2 concentration, net photosynthetic rate and transpiration rate showed good growth trends under 50 mmol/L concentration treatment, while its plant height and stem thickness grew the least significantly under strong alkaline salt stress of 150 mmol/L saline solution. The growth of plant height and stem thickness was the least obvious under 150 mmol/L saline solution of strong alkaline salt stress; 50 mmol/L saline treatment was favourable to the growth of Cabernet Sauvignon grapevine seedlings in a certain low concentration range.