| 摘要: |
| 【目的】研究不同浓度梯度外源褪黑素处理对盐胁迫下‘突尼斯’石榴扦插幼苗生长发育的影响，筛选对石榴幼苗盐胁迫缓解效应最适的外源褪黑素浓度。【方法】以‘突尼斯’石榴为试材，采用斜插法获得扦插幼苗。选择长势一致，高度为20 cm的扦插幼苗进行盆栽试验，每盆栽植15株幼苗，一共栽植30盆，平均分为完全空白对照组(CK0)、盐胁迫对照组（CK）和T1～T4共6个组，各组随机排列，移栽缓苗7 d后，CK和T1～T4组开始浇灌150 mmol/L NaCl 溶液来模拟盐胁迫环境，每2 d浇灌1次，共浇灌5次，每次300 mL/盆。盐胁迫处理10 d后，T1～T4组分别喷施100，150，200，250 μmol/L的外源褪黑素溶液，每2 d喷施1次，共喷施6次。各处理喷施外源褪黑素后50 d时，选取大小、生长状况相近的植株，测定根系长度、叶片叶绿素含量、叶片相对电导率、叶片中超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量，计算耐盐系数和耐盐综合评价值，分析不同浓度外源褪黑素对植株盐胁迫的缓解效应。【结果】与CK0相比，盐胁迫导致石榴扦插幼苗生长发育不良，叶片萎蔫，边缘呈黄褐色，叶片的叶绿素含量、SOD活性、根系长度等指标显著降低（P＜0.05），而MDA含量和相对电导率显著升高（P＜0.05）。喷施不同浓度外源褪黑素处理石榴幼苗各项指标均有所改善，其中T2处理组效果最好，其根系长度、叶绿素含量、SOD活性较CK处理分别显著增加了42.86%，50.21%和55.35%，而相对电导率和MDA含量分别显著降低了37.03%和45.34%。不同指标的耐盐系数有一定差异性。各处理耐盐综合评价值表现为：T2（0.505）＞T3（0.497）＞T1（0.494）＞T4（0.484）＞CK（0.447）。【结论】喷施150 μmol/L的外源褪黑素对石榴幼苗盐胁迫的缓解效应最佳，各项生长生理指标明显优于其他处理组。 |
| 关键词: 石榴 扦插幼苗 盐胁迫 外源褪黑素 |
| DOI：10.13207/j.cnki.jnwafu.2025.11.013 |
| 分类号: |
| 基金项目:林木育种与生态修复国家研究工程中心开放基金项目（LMYZKF2023001）；安徽省教育厅高校自然科学基金项目（KJ2020B21）；2022年安徽省质量工程“六卓越一拔尖”项目“卓越农林人才实践培养新路径探索——以园艺专业为例”（2022zybj085）；2023年安徽省质量工程“四新”研究与改革实践项目“新农科背景下园艺专业实践育人培养模式改革与创新”（2023sx068） |
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| Mitigating effects of exogenous melatonin on salt stress in Tunisian pomegranate seedlings |
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LIU Chun1, YANG Dekun1, LIU Jie1, XU Xiangfeng1, YANG Jing1, YANG Xingyue1, LI Jinjin2
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1.School of Life Sciences,Huaibei Normal University,Huaibei,Anhui 235000,China;2.Library,Huaibei Normal University,Huaibei,Anhui 235000,China
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| Abstract: |
| 【Objective】This research aimed to investigate the effects of exogenous melatonin treatment at different concentration gradients on the growth and development of ‘Tunisian’ pomegranate cuttings under salt stress,to screen the most suitable exogenous melatonin concentration for salt tolerance relief in pomegranate cutting seedlings.【Method】With ‘Tunisian’ pomegranate as the test material,cutting seedlings were obtained by oblique cutting method.Cutting seedlings of consistent growth condition with a height of 20 cm were selected for pot experiments.15 seedlings were planted in one pot,with a total of 30 pots.And they were divided into 6 groups:complete blank control group (CK0),salt stress control group (CK),and T1—T4,which were all randomly organized.After 7 days of transplanting,the CK and T1-T4 groups were treated with 150 mmol/L NaCl solution to simulate salt stress environment.The solution was applied once every 2 days for a total of 5 times,with 300 mL per pot.After 10 days of salt stress treatment,T1-T4 groups were sprayed with exogenous melatonin solutions of 100,150,200,and 250 μmol/L,once every 2 days,for a total of 6 times.After 50 days of spraying exogenous melatonin in each treatment,plants of similar size and growth status were selected to determine their root length,leaf chlorophyll content,leaf relative conductivity,superoxide dismutase (SOD) activity,and malondialdehyde (MDA) content in leaves.The salt tolerance coefficient and salt tolerance comprehensive evaluation value were calculated to analyze the alleviating effect of different concentrations of exogenous melatonin on plant salt stress.【Result】Compared with CK0,salt stress resulted in poor growth and development of pomegranate cutting seedlings, which was indicated by wilting of leaves,yellowing of edges,significant decrease in chlorophyll content,SOD activity,root length and other indicators of leaves (P<0.05),and significant increase in MDA content and relative conductivity (P<0.05).Spraying exogenous melatonin at different concentrations had improving effect on various indicators of pomegranate seedlings,with T2 treatment group showing the best effect.In T2 treatment group,the root length,chlorophyll content,and SOD activity increased significantly by 42.86%,50.21%,and 55.35%,respectively,compared to CK treatment.Relative conductivity and MDA content decreased significantly by 37.03% and 45.34%,respectively.There are certain differences in salt tolerance coefficients among different indicators.The comprehensive evaluation values of salt tolerance for each treatment ranked as T2(0.505)＞T3(0.497)＞T1(0.494)＞T4(0.484)＞CK(0.447).【Conclusion】Spraying exogenous melatonin at a concentration of 150 μmol/L had the best alleviating effect on salt stress in pomegranate seedlings,and various growth physiological indicators were significantly better than those in other treatment groups. |
| Key words: pomegranate cutting seedlings salt stress exogenous melatonin |
