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4个杜鹃品种对碱胁迫的耐受性分析

来源：花匠小妙招时间：2025-06-22 05:50

摘要：

【目的】分析碱胁迫下杜鹃属(Rhododendron)不同品种的耐受性差异,以及碱胁迫对植物不同器官中矿质元素积累和分布的影响,探讨杜鹃对碱胁迫的响应机制,为选育耐碱品种提供依据。【方法】用碱性盐溶液Na2CO3-NaHCO3(体积比1∶9)将去离子水pH分别调节至7.52(低碱)、9.14(高碱),选用盆栽浇灌碱液的方法对杜鹃4个品种(‘紫鹤’‘麒麟’‘胭脂蜜’和‘粉秀’)进行为期2个月的碱胁迫处理,观察植株生长情况,测定植株叶绿素含量、根系活力、铁还原酶活性、矿质元素含量等生理生化指标。【结果】杜鹃不同品种对碱胁迫耐受性差异显著,抗性弱的品种呈现叶片黄化或干枯脱落,根系发黑甚至死亡等碱害症状。随着碱胁迫程度的加深,不同品种苗高增量比率和干物质量均显著下降,其中‘麒麟’和‘胭脂蜜’的地下部分干物质量随碱胁迫程度的加深而显著减少,‘紫鹤’仅在高碱胁迫时显著降低,‘粉秀’则不同处理间无显著差异。碱胁迫处理导致杜鹃植株叶绿素含量和根系活力显著下降,根系铁还原酶活性升高,其中‘紫鹤’和‘粉秀’的根系活力在不同强度碱处理下差异不显著,‘麒麟’和‘胭脂蜜’均较对照显著下降,‘紫鹤’在高碱胁迫下根系铁还原酶活性显著较高于对照,其余3个品种在不同处理间无显著差异。随着碱胁迫程度加深,杜鹃体内不同矿质元素积累和分布受到影响,Na+和铁离子在根系中显著积累,K+、Ca2+集中分布在叶片,且含量明显下降。叶片中Na+含量变化因品种而异,碱胁迫处理后‘胭脂蜜’和‘麒麟’叶片中Na+含量显著增加,而‘紫鹤’和‘粉秀’中无显著变化。【结论】综合分析认为,杜鹃品种‘紫鹤’和‘粉秀’耐碱性较强,‘胭脂蜜’其次,‘麒麟’耐碱性较弱。

关键词: 杜鹃品种, 碱胁迫, 矿质元素, 耐碱性

Abstract:

【Objective】 This study aims to analyze the tolerance differences of Rhododendron cultivars to alkali stress and effects on accumulation and distribution of mineral elements in different organs of rhododendron, and investigate the response mechanism of rhododendron to alkali stress. The results of this study provide a theoretical basis for breeding alkali-tolerant varieties. 【Method】 Alkaline salt solution Na2CO3-NaHCO3 (volumn fraction 1∶9) was used to adjust the pH value of deionized water to 7.52 and 9.14, respectively. Four Rhododendron cultivars (Rhododendron ‘Zihe’, R. ‘Kirin’, R. ‘Yanzhi Mi’ and R. ‘Fenxiu’) were treated with pot watering of alkaline solution for two months, and the growth of plants, as well as physiological and biochemical indexes such as chlorophyll content, root vigor, ferric reductase activity and mineral content were measured. 【Result】 The different varieties of Rhododendron were significantly different in terms of their tolerance to alkali stress. Those plants with weak resistance showed symptoms of alkali damage, such as the yellowing of leaves or leaves drying and falling off, root blackening and even death. With an increase in alkaline stress, the high increment and dry matter ratio of the different varieties decreased significantly. The analysis of plant dry matter quality showed that the dry matter quality of the underground part of R. ‘Kirin’ and R. ‘Yanzhi Mi’ decreased significantly with the increasing degree of alkali stress; R. ‘Zihe’ significantly decreased under high alkali stress, and R. ‘Fenxiu’ had no significant difference among different treatments. The chlorophyll content and root activity of rhododendron decreased significantly, and root iron reductase activity increased. The root activity of R. ‘Zihe’ and R. ‘Fenxiu’ showed no significantly difference under different alkali intensities, while the root activity of R. ‘Kirin’ and R. ‘Yanzhi Mi’ significantly decreased compared with the control. Only R. ‘Zihe’ showed significantly higher root iron reductase activity than the control under high alkali stress, whereas the other three cultivars showed no significantly difference among different treatments. An increase in alkali stress affected the accumulation and distribution of different mineral elements in the rhododendron. Na and Fe ions content significantly accumulated in the root system, whereas K+ and Ca2+ were concentrated in the leaves, and the content decreased significantly. The content of Na+ in the leaves varied among cultivars. After alkali stress treatment, the content of Na+ in leaves of R. ‘Yanzhi Mi’ and R. ‘Kirin’ increased significantly, but there was no significant change in R. ‘Zihe’ and R. ‘Fenxiu. ’ 【Conclusion】 Based on the above indexes, R. ‘Zihe’ and R. ‘Fenxiu’ had strong alkali resistance, followed by R. ‘Yanzhi Mi’, and the alkali resistance of R. ‘Kirin’ was weak.

Key words: Rhododendron cultivar, alkali stress, mineral element, alkali tolerance

中图分类号:

S685.21