| 摘要: |
| 【目的】分析干旱胁迫下4个苹果砧木资源的生理特性，为筛选抗旱性强的苹果砧木奠定基础。【方法】以一年生苹果砧木M7、G935、M9T337和新疆野苹果幼苗为研究对象，采用盆栽法，设置干旱胁迫和对照处理，对照组土壤含水量为75%~80%，分别在干旱胁迫0，4，8，12，16，20，24 d采样测定其生理指标，并进行综合评价；利用逐步回归分析筛选关键抗旱指标，建立抗旱性评价的最优回归方程。【结果】随着干旱胁迫时间的延长，4个苹果砧木资源幼苗的叶绿素含量呈下降趋势，胁迫结束时M9T337的叶绿素含量最低(1.67 mg/g)；相对电导率，MDA和可溶性糖含量均呈不同程度的上升；可溶性蛋白含量，SOD、POD和CAT活性呈先增加后下降趋势。干旱胁迫24 d时，只有M9T337的可溶性蛋白含量低于CK（23.33%），G935的SOD活性低于CK（14.78%），其余砧木幼苗的可溶性蛋白含量和SOD活性均高于CK。主成分分析筛选出可溶性糖含量、POD活性、相对电导率和CAT活性可作为评价苹果砧木抗旱性的可靠指标。M7砧木的综合得分最大（0.451），其幼苗抗旱性最强；其次为新疆野苹果（0.421）和G935（0.413）；M9T337综合得分最小（0.352）,幼苗抗旱性最弱。根据筛选的4个指标建立了苹果幼苗抗旱性评价的最优回归方程，决定系数R2为0.977，表明该方程具有较强的解释能力，可以解释99.7%的数据变化，预测精度高达95%以上。【结论】可溶性糖含量、POD活性、相对电导率和CAT活性可用于抗旱苹果砧木的早期快速选择；4个苹果砧木资源幼苗的抗旱性依次为M7＞新疆野苹果＞G935＞M9T337，M7对干旱的适应能力强，可在旱地苹果产区推广应用。 |
| 关键词: 苹果砧木 抗旱性 生理特性 苹果育种 |
| DOI：10.13207/j.cnki.jnwafu.2025.11.012 |
| 分类号: |
| 基金项目:新疆维吾尔自治区重大科技专项（2022A02003-1）；新疆林果技术产业体系项目（XJLGCYJSTX04-2024） |
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| Effects of drought stress on physiological characteristics of four apple rootstock seedlings |
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WANG Zhuli1, JING Xilige2, LI Wensheng1, ZHANG Ping1
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1.College of Forestry and Landscape Architecture,Urumqi,Xinjiang 830052,China;2.College of Horticulture,Xinjiang Agricultural University,Urumqi,Xinjiang 830052,China
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| Abstract: |
| 【Objective】The study aimed to investigate the physiological characteristics of four apple rootstocks under drought stress,to lay the foundation for screening drought-resistant apple rootstocks.【Method】One-year-old seedlings of four apple rootstocks M7,G935,M9T337,and Xinjiang wild apple were subjected to prolonged drought stress and a control treatment (with soil moisture maintained at 75%-80%) by pot bioassay experiments.Physiological indexes were measured at 0,4,8,12,16,20,and 24 days after the initiation of drought stress,which were subsequently comprehensively evaluated.Key drought resistance indexes were screened by stepwise regression analysis to develop the optimal regression equation for drought resistance evaluation.【Result】With increasing duration of drought stress exposure,the chlorophyll content in seedlings of the four rootstocks showed a decreasing trend.By the termination of 24 d drought treatment,M9T337 had the lowest chlorophyll content at 1.67 mg/g.The relative conductivity,MDA content and soluble sugar content demonstrated varying degrees of increase.The soluble protein content,SOD activity,POD activity,and CAT activity initially increased and then decreased.At 24 d of drought stress,M9T337 exhibited lower soluble protein content compared to the control group (23.33%),whereas G935 showed lower SOD activity compared to the control (14.78%).The soluble protein content and SOD activity of the remaining rootstock seedlings were higher than those of the control group.The principal component analysis revealed that soluble sugar content,POD activity,relative conductivity and CAT activity could serve as reliable indexes for evaluating the drought resistance of apple rootstocks.M7 rootstock had the highest composite score (0.451),indicating its seedlings had the strongest drought resistance,followed by Xinjiang wild apple (0.421) and G935 (0.413).M9T337 had the lowest composite score (0.352),indicating its seedlings had the weakest drought resistance.The optimal regression equation for evaluating the drought resistance of apple seedlings was established based on the four selected indicators,with a coefficient of determination (R2) of 0.977,which indicated that the equation had strong explanatory power and could account for 99.7% of data variations,with the prediction accuracy exceeding 95%.【Conclusion】Soluble sugar content,POD activity,relative conductivity,and CAT activity can be used for early and rapid selection of drought resistant apple rootstocks.The drought resistance of the four apple rootstock seedlings was ranked as follows:M7＞Xinjiang wild apple＞G935＞M9T337.M7 exhibited a strong adaptive ability to drought and can be widely promoted in the dryland apple production areas. |
| Key words: apple rootstocks drought tolerance physiological characteristics apple breeding |
