外源Ca(NO_3)_2对NaCl胁迫下番茄幼苗生理特征的影响

Effects of Ca(NO_3)_2 on Physiological Characteristics of Tomato Seedlings under NaCl Stress

以番茄品种‘农城906’和"毛粉802’幼苗为材料,利用Hoagland基础培养液,研究在150 mmol/L NaCl胁迫下外源10、20、30和40 mmol/L Ca(NO3)2对番茄植株盐胁迫的缓解作用。结果显示,(1)NaCl胁迫显著降低了2个品种幼苗地上和地下部分干重、叶片叶绿素含量和根系活力,增加了幼苗的可溶性糖含量、细胞膜透性和MDA含量,同时使其CAT、POD、SOD活性显著降低;(2)添加20 mmol/L Ca(NO3)2能够有效提高盐胁迫条件下幼苗的地上和地下部干重,缓解叶绿素的降解和根系活力的下降,增加幼苗体内可溶性糖含量,降低叶片质膜透性和MDA含量,增强幼苗体内POD、CAT等细胞保护酶活性,但随着Ca(NO3)2浓度的继续增加,这种缓解作用逐渐减小。研究表明,一定浓度的外源Ca(NO3)2能有效缓解NaCl对番茄幼苗的生长和生理伤害,在一定程度上增强番茄幼苗对盐胁迫的耐受力,并以20 mmol/L Ca(NO3)2对NaCl胁迫的缓解效果最佳。

The abating effects of exogenous Ca（NO3）2 with 10,20,30,40 mmol/L concentrations were studied on tomato variety ＇Nongcheng 906＇ and ＇Maofen 802＇ under 150 mmol/L NaCl salt stress using the Hoagland as the basic nutrient solution.It showed that the stress of 150 mmol/L NaCl inhibited the shoot dry weight and the root dry weight,decreased the chlorophyll content and the root vigor significantly,enhanced the soluble sugar content,increased the cell membrane permeability and the MDA content,reduced the activities of SOD,POD,CAT remarkably.The exogenous Ca（NO3）2 of different concentration could alleviated effectively salt stress on the tomato seedlings,and the exogenous Ca（NO3）2 of 20 mmol/L could enhanced the dry matter quantity of shoot and root effectively,decline the membrane permeability and the MDA content,increase the activities of CAT,POD,SOD of seedlings,and enhance the soluble sugar content,and abate the degradation of chlorophyll and decreasing of root vigor,which indicated that the exogenous Ca（NO3）2 could enhance the tolerance to the salt stress,while the abating effect declined with the increase of Ca（NO3）2 concentration.It was considered that the exogenous Ca（NO3）2 had abated effect on growth and physiology of tomato seedlings,and the best abating effect of Ca（NO3）2 was at the concentration of 20 mmol/L.