| 摘要: |
| 为探究混合盐碱(NaCl-NaHCO3)胁迫对大丽花(Dahlia pinnata)生长生理的影响,以期为盐碱地大丽花品种的筛选与利用提供理论依据,该研究以其4个品种(‘奶油桃子'‘牛奶咖啡'‘克里夫灵感'和‘双吉尔')为试材,采用盆栽法设置0、50、100、150 mmol·L-1 共4个盐碱胁迫浓度,分别于胁迫7、14、21 d测定其生长、光合参数、渗透调节和抗氧化酶活性等指标。结果表明:(1)盐碱胁迫显著抑制大丽花幼苗生长,且抑制程度随浓度和时间递增; 品种间差异显著,耐盐碱性最强品种‘双吉尔'的生长量远高于盐碱敏感品种‘克里夫灵感'。(2)随着盐碱胁迫加剧,净光合速率、气孔导度和蒸腾速率均显著降低,而胞间CO2浓度先降后升,其中‘双吉尔'始终保持最高的净光合速率。(3)随着胁迫浓度增加,叶片相对含水量持续下降,但‘双吉尔'在重度胁迫下仍维持66.4%的较高水平; 丙二醛含量大幅升高,膜脂过氧化加剧,同时脯氨酸和可溶性糖持续积累,抗氧化酶系统在轻中度胁迫下被激活,重度胁迫下仅‘双吉尔'能维持较高酶活性。(4)100 mmol·L-1为耐盐碱性分化临界浓度,盐碱敏感品种‘克里夫灵感'出现不可逆损伤。(5)品种间耐盐碱性差异显著(P<0.05),隶属函数综合评价得出耐盐碱性强弱顺序为‘双吉尔'>‘牛奶咖啡'>‘奶油桃子'>‘克里夫灵感'。综上,混合盐碱胁迫下大丽花幼苗的生理适应性表现为品种特异性,耐盐碱性品种‘双吉尔'通过维持较高的光合能力、水分保持能力和抗氧化酶活性,在重度胁迫下仍能保持相对稳定的生理状态,可作为盐碱地绿化推广的优选品种。 |
| 关键词: 大丽花, 混合盐碱胁迫, 形态特征, 生理特性, 综合性评价 |
| DOI：10.11931/guihaia.gxzw202602005 |
| 分类号:Q945 |
| 文章编号:1000-3142(2026)07-1200-15 |
| 基金项目:2024年高校教师创新基金项目(2024B-081); 甘肃农业大学科技创新基金-学科建设专项基金(GAU-XKJS-2018-114)。 |
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| Evaluation of physiological adaptability of four Dahlia pinnata cultivars under saline-alkali stress at seedling stage |
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WANG Yaqin, LIU Wenlan*
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College of Forestry, Gansu Agricultural University, Lanzhou 730070, China
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| Abstract: |
| To investigate the effects of mixed saline-alkali stress(NaCl-NaHCO3 )on the growth and physiology of Dahlia pinnata, and to provide a theoretical basis for the selection and utilization of D. pinnata cultivars in saline-alkali areas, four cultivars(‘Cream Peach', ‘Milk Coffee', ‘Cliff Inspiration', and ‘Double Gill')were subjected to four stress concentrations(0, 50, 100, 150 mmol·L-1)in a pot experiment. Growth, photosynthetic parameters, osmotic adjustment, and antioxidant enzyme activities were measured at 7, 14, and 21 d after stress initiation. The results were as follows:(1)Saline-alkali stress significantly inhibited the growth of D. pinnata seedlings, and the inhibition increased with stress concentration and duration; significant differences were observed among cultivars, and the growth of the most saline-alkali tolerant cultivar ‘Double Gill' was much higher than that of the saline-alkali sensitive cultivar ‘Cliff Inspiration'.(2)With increasing saline-alkali stress, net photosynthetic rate, stomatal conductance, and transpiration rate all decreased significantly, while intercellular CO2 concentration firstly decreased and then increased. Among the cultivars, ‘Double Gill' consistently maintained the highest net photosynthetic rate.(3)As stress concentration increased, leaf relative water content continuously decreased, but ‘Double Gill' still maintained a relatively high level of 66.4% under severe stress; malondialdehyde content increased sharply, and membrane lipid peroxidation aggravated. Meanwhile, proline and soluble sugars accumulated continuously. The antioxidant enzyme system was activated under mild and moderate stresses, but under severe stress, only ‘Double Gill' maintained high enzyme activity.(4)The concentration of 100 mmol·L-1 was identified as the critical concentration for saline-alkali tolerant differentiation, at which the saline-alkali sensitive cultivar ‘Cliff Inspiration' exhibited irreversible damage.(5)There were significant differences in saline-alkali tolerance among cultivars(P<0.05). The membership function analysis ranked the saline-alkali tolerance in the following order: ‘Double Gill' > ‘Milk Coffee' > ‘Cream Peach' > ‘Cliff Inspiration'. In conclusion, the physiological adaptability of D. pinnata seedlings under mixed saline-alkali stress is cultivar-specific. The saline-alkali tolerant cultivar ‘Double Gill' maintains relatively stable physiological status under severe stress by sustaining higher photosynthetic capacity, water retention ability, and antioxidant enzyme activities, making it a promising candidate for greening in saline-alkali areas. |
| Key words: Dahlia pinnata, mixed saline-alkali stress, morphological characteristics, physiological traits, comprehensive evaluation |
