【摘要】 干旱胁迫作为制约苹果栽培的关键非生物因子，显著影响果树生理代谢及果实商品性。本研究针对苹果砧穗互作体系，通过多维度生理指标分析和综合隶属函数分析对其幼苗的抗旱性进行评价，旨在为干旱区苹果栽培技术体系优化提供理论支撑。试验以8个一年生苹果砧穗组合(XM7、X5M7、XG、X5G、XMT、X5MT、XW、X5W)为试材，设置持续干旱处理，于处理第0(CK)、4、8、12、16、20、24天分别测定其叶片相对电导率(REC)和丙二醛(MDA)、可溶性糖(SS)、可溶性蛋白(SP)、叶绿素(Chl)含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的动态响应，并对所测各指标进行相关性分析、主成分分析(PCA),继而在主成分分析基础上用隶属函数法对各苹果砧穗组合的抗旱性进行综合评价。结果表明：(1)随干旱胁迫时间延长，8个苹果砧穗组合幼苗叶片叶绿素含量持续下降，较对照降幅达21.21%～44.97%,相对电导率和丙二醛、可溶性糖含量呈线性累积，较对照增幅分别为144.62%～168.91%、93.51%～128.51%、41.20%～112.85%,而可溶性蛋白含量与SOD、POD、CAT活性呈先升后降趋势，峰值出现在胁迫第8天至第16天之间；(2)关键指标间存在显著关联性：CAT活性与SOD活性、可溶性蛋白含量均呈极显著正相关，POD活性与叶绿素含量、相对电导率与可溶性蛋白含量呈极显著负相关；(3)主成分分析提取到两个主成分，可解释85.66%的成分信息，基于主成分分析结果构建的综合抗旱指数(D值)表明，8个苹果砧穗组合的抗旱性强弱排序为XW>X5W>XMT>X5MT>X5G>XG>XM7>X5M7,XW砧穗组合(新疆野苹果砧木)在抗旱栽培中具有显著优势。该研究结果可为苹果抗旱砧穗组合选配及果园抗旱栽培技术管理提供理论依据。更多还原

【Abstract】 Drought stress, as a key abiotic factor restricting apple cultivation, significantly affects the physiological metabolism of fruit trees and the commercialization of fruits. This study aimed to evaluate the drought resistance of apple rootstock-scion interaction systems through multi-dimensional physiological indicator analysis and comprehensive membership function analysis, to provide theoretical support for optimizing apple cultivation techniques in arid areas. Eight one-year-old apple rootstock-scion combinations(XM7, X5M7, XG, X5G, XMT, X5MT, XW, X5W) were used as test materials and subjected to continuous drought treatment. Measurements were taken after 0, 4, 8, 12, 16, 20 and 24 days of treatment, including leaf relative electrical conductivity(REC), contents of malondialdehyde(MDA), soluble sugar(SS), soluble protein(SP) and chlorophyll(Chl), and activity dynamics of superoxide dismutase(SOD), peroxidase(POD) and catalase(CAT). Correlation analysis and principal component analysis(PCA) were performed on the measured indicators, followed by the comprehensive evaluation on drought resistance of each apple rootstock-scion combination using membership function analysis. The results were as follows.(1) With prolonged drought stress, the leaf chlorophyll content of the eight apple rootstock-scion combinations continuously decreased, with a reduction of 21.21% to 44.97% compared to the control. electrical conductivity, and the contents of MDA and SS showed linear accumulation, with increases of 144.62% to 168.91%, 93.51% to 128.51%, and 41.20% to 112.85%, respectively, compared to the control; the soluble protein content and SOD, POD and CAT activities firstly increased and then decreased, peaking between the 8th and 16th day of stress.(2) There were significant correlations among key indicators: CAT activity was significantly positively correlated with SOD activity and soluble protein content, while POD activity was significantly negatively correlated with chlorophyll content, and relative electrical conductivity was significantly negatively correlated with soluble protein content.(3) Through principal component analysis, two principal components were extracted, explaining 85.66% of the variance information. Based on the comprehensive drought resistance index(D value) constructed from the PCA results, the drought resistance of the eight apple rootstock-scion combinations were sequenced as XW > X5W > XMT > X5MT > X5G > XG > XM7 > X5M7. The XW combination(using Malus sieversii as rootstock) showed significant advantages in drought-resistant cultivation. The results of this study could provide theoretical references for rootstock combination selection and orchard water management in apple.更多还原