三色堇对NaCl胁迫的生理响应

为了探讨三色堇对NaCl胁迫的生理响应机制及生长特性，探索三色堇对NaCl的最高耐受浓度，以三色堇为研究材料，采用0、25、50、100、150、200 mmol·L^-1的NaCl对三色堇进行处理。结果表明，NaCl处理对三色堇渗透调节系统、抗氧化酶系统、光合色素、丙二醛（MDA）含量以及株高生长量有明显的影响。在处理后14 d，随处理浓度升高，可溶性糖（SS）、可溶性蛋白（SP）、游离脯氨酸（Pro）、过氧化氢酶（CAT）、过氧化物酶（POD）、超氧化物歧化酶（SOD）、总叶绿素（Chl）表现出先升高后降低的趋势，MDA呈升高趋势，株高生长量呈降低趋势。隶属函数分析表明，当土壤中NaCl浓度≤150 mmol·L^-1时对三色堇的生长无明显抑制作用，当浓度>150 mmol·L^-1时，对生长抑制作用明显。因此，三色堇耐NaCl的最高浓度为150 mmol·L^-1，超过此浓度，代谢调节系统和抗氧化酶系统会受到严重影响，Chl降解加剧，光合系统遭到严重破坏，三色堇的生长受到严重的影响。

Physiological response of Viola tricolor to NaCl stress

This research investigated the physiological response mechanisms and growth characteristics of Viola tricolor in response to NaCl stress and explored the maximum NaCl concentration tolerated by V. tricolor. In a pot experiment， 45-day old seedlings of V. tricolor were subjected to different NaCl concentrations （0， 25， 50， 100， 150 and 200 mmol·L^-1）. It was found that NaCl treatment at higher concentrations had obvious effects on the osmotic regulation system， antioxidant enzyme system， photosynthetic pigment， malondialdehyde content and plant height of V. tricolor. With increase in NaCl concentration， soluble sugar， soluble protein， free proline and chlorophyll contents， together with catalase， peroxidase and superoxide dismutase activities， initially increased and then decreased. MDA concentration exhibited a pattern of continuous increased， and height growth decreased on the 14th day of NaCl stress with increasing NaCl concentration. A membership function analysis showed no obvious inhibitory effect of NaCl on the growth of V. tricolor when the concentration of NaCl in soil was ≤150 mmol·L^-1 but in contrast， NaCl had an obvious inhibitory effect on V. tricolor growth when the concentration was >150 mmol·L^-1. Therefore， the maximum NaCl concentration tolerance of V. tricolor was 150 mmol·L^-1， above which， the metabolic regulation system and antioxidant enzyme system were seriously affected， chlorophyll degradation was intensified， the photosynthetic system was seriously damaged， and the growth of V. tricolor was seriously reduced.