Page 105 - 《广西植物》2026年第7期
P. 105
7 期 王亚琴等: 盐碱胁迫下 4 个大丽花品种幼苗生理适应性评价 1 2 0 1
Abstract: To investigate the effects of mixed saline ̄alkali stress ( NaCl ̄NaHCO ) on the growth and physiology of
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Dahlia pinnataꎬ and to provide a theoretical basis for the selection and utilization of D. pinnata cultivars in saline ̄alkali
areasꎬ four cultivars (‘Cream Peach’ ‘Milk Coffee’ ‘Cliff Inspiration’ and ‘Double Gill’) were subjected to four
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stress concentrations (0ꎬ 50ꎬ 100ꎬ 150 mmolL ) in a pot experiment. Growthꎬ photosynthetic parametersꎬ osmotic
adjustmentꎬ and antioxidant enzyme activities were measured at 7ꎬ 14ꎬ and 21 d after stress initiation. The results were
as follows: ( 1) Saline ̄alkali stress significantly inhibited the growth of D. pinnata seedlingsꎬ and the inhibition
increased with stress concentration and durationꎻ significant differences were observed among cultivarsꎬ 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 stressꎬ net photosynthetic rateꎬ stomatal conductanceꎬ and
transpiration rate all decreased significantlyꎬ while intercellular CO concentration firstly decreased and then
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increased. Among the cultivarsꎬ ‘Double Gill’ consistently maintained the highest net photosynthetic rate. (3) As stress
concentration increasedꎬ leaf relative water content continuously decreasedꎬ but ‘ Double Gill’ still maintained a
relatively high level of 66.4% under severe stressꎻ malondialdehyde content increased sharplyꎬ and membrane lipid
peroxidation was aggravated. Meanwhileꎬ proline and soluble sugars accumulated continuously. The antioxidant enzyme
system was activated under mild and moderate stressesꎬ but under severe stressꎬ only ‘Double Gill’ maintained high
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enzyme activity. (4) The concentration of 100 mmolL was identified as the critical concentration for saline ̄alkali
tolerant differentiationꎬ 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 comprehensive
evaluation of membership functions showed that the order of saline ̄alkali resistance strength was ‘Double Gill’ > ‘Milk
Coffee’ > ‘Cream Peach’ > ‘Cliff Inspiration’. In conclusionꎬ 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 capacityꎬ water retention abilityꎬ and
antioxidant enzyme activitiesꎬ making it a promising candidate for greening in saline ̄alkali areas.
Key words: Dahlia pinnataꎬ mixed saline ̄alkali stressꎬ morphological characteristicsꎬ physiological traitsꎬ
comprehensive evaluation
土壤盐渍化作为全球性生态问题ꎬ在气候变 作机制胁迫植物(詹振楠和纪婷ꎬ2019)ꎮ 第一ꎬ高
化与人为活动加剧的背景下持续恶化ꎮ 据联合国 浓度 Na 竞争性置换细胞膜脂双分子层中的 Ca ꎬ
2+
+
粮农组织( FAO) 统计ꎬ全球约 20%的灌溉农业区 导致膜透性增加与 K 外流ꎬ破坏离子稳态ꎬ同时
+
遭受盐碱化威胁ꎬ覆盖可耕地总面积的 1 / 3ꎬ预计 HCO 引发的碱性环境(pH>8.5)降低 Fe 和 Mn 2+
2+
-
3
至 2050 年 受 影 响 区 域 将 超 50% ( 王 佳 丽 等ꎬ 等微量元素有效性ꎬ抑制叶绿素合成关键酶活性
2011)ꎮ 我国作为盐渍化重灾国ꎬ现有盐碱地面积 (戴森焕等ꎬ2022)ꎮ 第二ꎬ盐离子积累形成低水势
约 3 690 万 hm ꎬ其中西北干旱区因蒸发强烈、盐 环境ꎬ阻碍根系水分吸收ꎬ引发细胞生理性脱水ꎬ
2
分表聚ꎬ土 壤 盐 碱 化 问 题 尤 为 突 出 ( 杨 劲 松 等ꎬ 迫使气孔关闭以减少蒸腾ꎬ进而降低胞间 CO 浓度
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2022)ꎮ 西北地区盐碱化土壤类型主要为中性盐 (C )与净光合速率( P ) ( 郭丽丽等ꎬ2018)ꎮ 更为
i n
(NaCl)与碱性盐( NaHCO )ꎬ二者通过渗透胁迫、 关键的是ꎬ离子毒害与渗透胁迫协同触发活性氧
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离子毒害及高 pH 值协同作用ꎬ严重制约植物生长 ( reactive oxygen speciesꎬ ROS)爆发ꎬ其氧化攻击使
与生态修复进程(于宝勒ꎬ2021)ꎮ 在此背景下ꎬ解 膜脂 不 饱 和 度 下 降ꎬ 丙 二 醛 ( malondialdehydeꎬ
析植物耐盐碱机制并筛选适应性种质资源ꎬ对盐 MDA)含量升高标志着膜系统损伤ꎬ此时超氧化物
碱地生态治理与可持续开发具有迫切意义ꎮ 歧化酶( superoxide dismutaseꎬ SOD)、过氧化物酶
盐碱胁迫对植物的生长发育与生态适应能力 (peroxidaseꎬ POD)、过氧化氢酶( catalaseꎬ CAT)
均会造成严重影响( 付丽等ꎬ2021)ꎮ 土壤盐碱化 构成的三级抗氧化防御体系被激活以清除 ROS
主要通过离子干扰、渗透失衡与氧化损伤三重互 (张绪超等ꎬ2019)ꎮ 植物通过积累脯氨酸、甜菜碱

