摘要: 为探讨盐胁迫下外源壳聚糖(Chitosan, CTS)和外源亚精胺(Spermidine, Spd)处理对黄瓜幼苗光合作用的影响，以“津优1号”(Cucumis sativus L.)为试验材料，在200 mmol/l NaCl胁迫条件下，采用基质培育法，设置5组处理(CK清水，S1 Nacl，S2 NaCl、CTS，S3 NaCl、Spd，S4 NaCl，CTS，Spd)，研究了150 mg/g外源壳聚糖和150 mg/g外源亚精胺对黄瓜幼苗叶绿素荧光参数(PSII光化学效率)、叶绿素含量、植株生长量等指标的影响。研究表明：在NaCl盐胁迫下，无论Spd、CTS单一处理还是共同处理下，均能缓解盐胁迫的伤害。外源Spd，CTS影响NaCl盐胁迫下黄瓜幼苗叶绿素荧光参数变化，提高植株的光化学效率，NPQ、F0在NaCl盐胁迫下均有所上升，而Fm、Fv/Fm、Y(II)、qP在处理下均有所下降。在NaCl盐胁迫下，Spd、CTS共同处理NPQ、F0的升幅均小于单一处理，Fm、Fv/Fm、Y(II)、qP的降幅均小于单一处理，Spd、CTS共同处理作用效果更显著。Spd、CTS共同处理显著提高叶绿素含量，在NaCl盐胁迫下提高量最高可达30.37%，显著高于单一处理，并且持续诱导9天以上效果较佳。CTS、Spd共同处理作用下，茎粗、株高、叶面积、地上鲜重、根鲜重比盐胁迫对照最高量提高分别可达27.64%、20.59%、26.76%、39.24%、39.79%，增长量明显高于Spd、CTS单独处理。且Spd、CTS在盐胁迫下黄瓜幼苗叶片叶绿素含量，叶绿素荧光参数均存在显著差异及极显著差异。
Abstract:
To explore the effect of cucumber seedling photosynthesis on exogenous Spermidine (Spd) and Chitosan (CTS) under salt stress as well as their interaction effect, using Jinyou No.1 (Cucumis sativus L.) as test materials under NaCl salt stress (200 mmol/l), adopting substrate cultivation and setting 5 treatments (CK water, S1 NaCl, S2 NaCl + CTS, S3 NaCl + Spd, S4 NaCl + CTS + Spd), the effects of cucumber seedling under salt stress with exogenous CTS (150 mg/g) and Spd (150 mg/g) about seedling growth, chlorophyll content, chlorophyll fluorescence parameters (PSII photochemical efficiency) and so on were studied. Study showed that the treatments of exogenous CTS and Spd relieved cucumber seedling injure under salt stress, whatever integrated treatments or independent treatments. Exogenous CTS and Spd influenced chlorophyll fluorescence parameters of cucumber seedlings under NaCl salt stress that could improve seedlings’ photochemical efficiency. Effect of integrated treatment of Spd and CTS was greater than that of independent treatment of chlorophyll fluorescence parameters. Chlorophyll content of integrated treatments was obviously much more than that of independent treatments. All treatments enhanced cucumber seedling salt tolerance, and persistent induction more than 9 days can be optimum. With integrated treatments, increments of stem diameter, plant height, leaf area, the ground fresh weight, and underground fresh weight were much more than those of cucumber seedling under salt stress, respectively up to 27.64%, 20.59%, 26.76%, 39.24%, and 39.79%. What’s more, these increments of integrated treatments were obviously much more than those of independent treatments. Significant or extremely significant interaction of SA and CTS was observed as chlorophyll content and chlorophyll fluorescence parameters.