盐碱胁迫对‘赤霞珠’葡萄幼苗生长及相关生理指标的影响

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

【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耐盐碱能力。【方法】以1年生‘赤霞珠’自根苗为试材,用NaCl、Na_(2)SO_(4)、NaHCO_(3)、Na_(2)CO_(3)按不同比例混合配制中性盐、弱碱性盐、强碱性盐3组复合盐溶液,每组各设置50,100,150 mmol/L 3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)‘赤霞珠’幼苗茎粗和叶面积随盐碱胁迫浓度增大呈现先增大后减小的趋势,而株高基本呈现下降趋势。幼苗株高在强碱性盐组150 mmol/L胁迫处理10 d和40 d时都较同期中性、弱碱性组相应浓度显著降低。(2)随着盐碱浓度的增大,‘赤霞珠’幼苗叶片的SOD活性及MDA含量呈先增大后减小的趋势,而POD活性呈现缓慢增加的趋势;强碱性盐组叶片POD活性在胁迫处理30~50 d时均高于相应浓度的中性、弱碱性盐组,但到处理60 d后逐渐低于相应浓度其他两处理组,并以150 mmol/L浓度表现得更明显。(3)‘赤霞珠’幼苗叶片胞间CO_(2)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CO_(2)浓度和净光合速率均为50 mmol/L浓度处理时较高;在同期相同盐碱浓度处理下,叶片净光合速率在强碱性盐150 mmol/L胁迫处理75 d时显著低于中性、弱碱性处理组。【结论】‘赤霞珠’幼苗株高、叶面积、胞间CO_(2)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150 mmol/L强碱性盐胁迫处理下增长不明显;一定范围内低浓度(50 mmol/L)盐碱胁迫有利于‘赤霞珠’葡萄幼苗生长。

[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,Na_(2)SO_(4),NaHCO_(3),and Na_(2)CO_(3)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 CO_(2)concentration,net photosynthetic rate and transpiration rate of‘Cabernet Sauvignon’seedlings showed a decreasing trend with the increase in salinity concentration,and their intercellular CO_(2)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 CO_(2)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.