【摘要】 探究矮化砧木在盐胁迫下的生长及生理响应，为盐渍化地区苹果栽培模式向矮砧密植方向转型及苹果产业的可持续发展提供理论依据。以自选优系P1自根砧为试材，利用五种不同浓度的NaCl溶液(0 mmol·L^-1、25 mmol·L^-1、50 mmol·L^-1、75 mmol·L^-1、100 mmol·L^-1)进行处理，3 d处理1次，共处理5次，动态监测生物量、叶片与根系形态、叶绿素含量、根系活力、相对电导率（REC）、丙二醛（MDA）、渗透调节物质、过氧化氢（H₂O₂）、超氧阴离子（O₂^-·）含量，抗氧化酶活性等生理指标。结果表明，短期25 mmol·L^-1盐胁迫处理，能促进苹果砧木P1叶绿素的合成及地下根系的生长，提高根系抗氧化酶活性，而O₂^-·、相对电导率（REC）、可溶性糖含量（SS）、脯氨酸（Pro）含量略有下降或差异不显著。随盐胁迫加剧，P1砧木的叶片变黄脱落，根系生长及根系活力受到抑制，抗氧化酶活性降低，H₂O₂、O₂^-·含量积累，使膜脂过氧化加剧，细胞膜透性增强，渗透调节物质增多。综上，25 mmol·L^-1浓度盐处理时，P1砧木通过促进叶绿素的合成、增加地下根系生物量的分配、提高抗氧化能力抵抗盐胁迫；随盐胁迫加剧，P1砧木通过积累SS、Pro含量抵抗盐胁迫，表明其有一定的耐盐能力，可在部分盐渍化地区推广种植。更多还原

【Abstract】 To investigate the growth and physiological response of dwarfing rootstocks under salt stress, this study provides a theoretical basis for the transition of apple cultivation mode to high-density dwarfing rootstocks and sustainable development of the apple industry in Saline-alkali regions. Using the self-rooted rootstock P1 as the test material, and five different concentrations of NaCl solutions(0, 25, 50, 75, and 100 mmol·L^-1) as three-day intervals for a total of 5 treatments,the biomass, leaf and root morphology, chlorophyll content, root vigour, relative electrical conductivity（REC）,malondialdehyde（MDA）, osmoregulators, hydrogen peroxide（H₂O₂）, superoxide anion（O₂^-·） content, and antioxidant enzyme activities are dynamically monitored. The results show that short-term 25 mmol·L^-1 salt stress treatment can promote chlorophyll synthesis and underground root growth in P1, and increase root antioxidant enzyme activity. But the content of O₂^-·, relative conductivity（REC）, soluble sugar（SS）, and proline（Pro） slightly decrease or show little difference. With the enhancement of salt stress, the leaves of P1 turn yellow and fell off, root growth and root vigour inhibit, the activity of antioxidant enzymes reduces, and the content of H₂O₂, O₂^-· accumulates, which leads to the intensification of membrane lipid peroxidation, the enhancement of cell membrane permeability and the increase of osmotic regulating substances. In conclusion, under 25 mmol·L^-1 salt stress, P1 resists salt stress by promoting chlorophyll synthesis, increasing underground root biomass allocation and improving antioxidant capacity. When the salt stress is intensified, P1 resists salt stress by accumulating SS and Pro, demonstrating moderate salt tolerance and potential for cultivation in mildly saline-alkali regions.更多还原