| 摘要: |
| 【目的】探讨磷肥施用下移深度对苜蓿越冬器官在低温胁迫下抗氧化生理特性的变化及其与抗寒性的关系。【方法】以‘北极熊’紫花苜蓿品种为供试材料，将磷肥施于地表和距离地表7.5，15，22.5，30 cm，分别以S0、S1、S2、S3、S4表示，并以不施磷肥为对照（CK）；于越冬期对苜蓿根颈模拟低温（4，-10，-20和-30 ℃）胁迫处理，检测丙二醛（MDA）含量、超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性的变化，并分析MDA含量与抗氧化酶活性的相关性。【结果】在同一施磷深度下，随着胁迫温度的降低，苜蓿根颈MDA含量呈先降低后增加的变化趋势，以-10 ℃下最低；SOD、POD、CAT活性则呈先增加后降低的变化趋势，且均在-10 ℃下最大；在同一低温胁迫处理下，不同施磷深度处理的MDA含量均明显低于CK，且在S2处理下MDA含量最低，较CK降低了48.61％～50.92％；不同施磷深度处理的SOD、POD、CAT活性均明显高于CK，且在S2处理下SOD、POD、CAT活性最强，分别较CK增长了26.42％～35.61％，53.37％～84.67％和24.94％～61.58％。相关性分析表明，在4，－10，－20和－30 ℃下，SOD、POD、CAT活性与MDA含量呈显著或极显著负相关。【结论】在距离土壤表面15 cm处施用磷肥最有利于提高苜蓿抗氧化酶活性，进而降低MDA含量，增强苜蓿抗寒性。 |
| 关键词: 苜蓿栽培 施磷深度 抗氧化酶 抗寒性 |
| DOI： |
| 分类号: |
| 基金项目:内蒙古自然科学研究基金项目(2020MS03081)；国家自然科学基金项目(31960352)；内蒙古自治区科技计划项目(2021GG0109) |
|
| Effect of phosphate fertilizer application depth on antioxidant enzyme activity and cold resistance of alfalfa root crown |
|
XIA Quanchao,ZHANG Yuxia,SUN Mingxue,et al
|
| Abstract: |
| 【Objective】This study explored the effect of application depth of phosphate fertilizer on physiological anti oxidation characteristics of overwintering organs of alfalfa under low temperature stress and the relationship with cold resistance.【Method】The ‘Gibraltar’ alfalfa variety was selected for test and phosphate fertilizer was applied on the ground and at depths of 7.5,15,22.5 and 30 cm from the ground (represented as S0,S1,S2,S3 and S4) using no application as the control (CK).Treatments with low temperature (4,-10,-20 and -30 ℃) stress were conducted to detect changes in malondialdehyde (MDA) content and activities of superoxide dismutase (SOD),peroxidase (POD) and catalase (CAT).The correlations between MDA content and activities of antioxidant enzymes were then analyzed.【Result】Under same phosphorus application depths,the MDA content of alfalfa root neck showed a trend of first decreasing and then increasing as the decrease of stress temperature with the lowest value at -10 ℃.SOD,POD and CAT activities increased first and then decreased with the maximum values at -10 ℃.Under same low temperature stress,the MDA contents of different phosphorus application depth treatments were significantly lower than that of CK.The lowest value under S2 treatment was 48.61%-50.92% lower than that of CK.SOD,POD,and CAT activities of different phosphorus application depth treatments were significantly higher than that of CK,and the strongest SOD,POD and CAT activities under S2 treatment were increased by 26.42%－35.61%,53.37%－84.67% and 24.94%－61.58% compared with CK,respectively.Correlation analysis showed that activities of SOD,POD and CAT had significant or extremely significant negative correlations with MDA contents.【Conclusion】Applying phosphate fertilizer at the depth of 15 cm was optimal to improve the cold resistance of alfalfa by increasing activities of antioxidant enzymes and reducing MDA content. |
| Key words: alfalfa cultivation phosphorus application depth antioxidant enzymes cold resistance |
