【摘要】 为探究苗期不同渗透胁迫水平对切花菊幼苗生理活性和叶片解剖结构的影响，以6个品种切花菊扦插幼苗为试材，用不同摩尔浓度，即0（CK）、50、100、150、200 mmol·L^-1的NaCl和NaHCO₃水溶液模拟盐和碱胁迫，不同质量分数，即0（CK）、5%、10%、15%、20%的聚乙二醇（PEG）6000模拟干旱胁迫。并于胁迫7 d后比较不同处理间的切花菊幼苗质膜相对透性、膜质过氧化、叶绿素含量、水分状况、活性氧、抗氧化系统、有机渗透调节物质等指标差异。结果表明，渗透胁迫是影响切花菊幼苗的主导因素，在盐、碱胁迫为200 mmol·L-1和干旱胁迫为20%时，幼苗生长受抑制最强，碱胁迫伤害最大。随着渗透胁迫加重，幼苗相对电导率、超氧化物歧化酶和过氧化物酶活性及丙二醛、可溶性糖和可溶性蛋白含量整体升高，叶片相对含水量和叶绿素含量整体降低。运用隶属函数法筛选出抗逆性好的柠檬酒品种和抗逆性弱的卡斯特品种，经叶片解剖结构验证，两个抗性不同的品种解剖结构有所差异，柠檬酒的叶片、上表皮、下表皮、中脉厚度和栅海比值高于卡斯特。本研究结果为筛选适应宁夏地区气候和土壤条件、非生物胁迫耐性强的切花菊品种提供了理论参考。更多还原

【Abstract】 To explore the impact of different levels of osmotic stress during the seedling stage on the physiological activity and leaf anatomical structure of chrysanthemum seedlings, six varieties of chrysanthemum cuttings were employed as experimental subjects. NaCl and NaHCO₃ solutions of different molar concentrations [0（CK）, 50, 100, 150, and 200 mmol·L^-1] were used to represent salt and alkali stress. Polyethylene glycol（PEG） 6000 solutions of varying mass fractions [0（CK）, 5%, 10%, 15%, and 20%] were used to simulate drought stress. After 7 days of stress, the differences relative permeability of plasma membrane, membrane lipid peroxidation, chlorophyll content, water status, reactive oxygen species, antioxidant system, and organic osmotic adjustment substances among the various treatments were compared. The results showed that osmotic stress was the primary factor affecting chrysanthemum seedlings, with the most significant growth inhibition occurring under 200 mmol·L^-1 salt and alkali stress and 20% drought stress, where alkali stress inflicted the most severe damage. As osmotic stress intensified, there was an increase in relative conductivity, superoxide dismutase, and peroxidase activities, as well as in the contents of malondialdehyde, soluble sugars, and soluble proteins in the seedlings, while the relative water content and chlorophyll content of the leaves decreased. Employing the membership function method, the lemonade variety, exhibiting strong stress resistance, and the caster variety, showing weak stress resistance, were identified. Verification through leaf anatomical structure confirmed distinct anatomical structures between the two varieties with different resistance levels, with the lemonade variety having higher leaf, upper epidermis, lower epidermis, midrib thickness, and palisade/spongy ratio than the caster variety. The results of this study offer a theoretical basis for the selection of chrysanthemum varieties with strong non-biological stress tolerance that are suitable for local climate and soil conditions.更多还原