AM真菌和施钾对宁夏枸杞响应干旱胁迫的交互影响

Interactive Effects of Arbuscular Mycorrhizal Fungus and Potassium Application on Response of Lycium barbarum to Drought Stress

通过盆栽控水法研究干旱条件下接种丛枝菌根真菌(arbuscular mycorrhizal fungus,AMF)根内球囊霉(Rhizophagus irregularis,Ri)和施钾对宁夏枸杞生长、各组织中钾元素含量、叶片抗氧化酶活性及叶绿素荧光参数的影响。结果表明:干旱条件下,随着施钾量的升高,AMF侵染率逐渐升高;AMF和施钾均不同程度地影响了宁夏枸杞的生长,提高了宁夏枸杞根和叶中的钾元素含量。干旱条件下,施钾显著提高了宁夏枸杞叶片的PSⅡ最大光化学量子产量(Fv/Fm)、PSⅡ实际光化学量子产量(ФPSⅡ)、光合电子传递速率(ETR),降低了非光化学猝灭系数(qN);AMF在不同施钾水平下均显著提高了宁夏枸杞叶片的Fv/Fm、ФPSⅡ、ETR、光化学猝灭系数(qP),降低了qN。干旱胁迫时,随着施钾量的升高,宁夏枸杞叶片的超氧化物歧化酶(SOD)、过氧化物酶(POD)活性增强,过氧化氢酶(CAT)活性变化不显著;在施钾量2mmol时,AMF显著提高了叶片POD、SOD的酶活性。因此,AMF和钾能够通过调控植物体的营养状况、提高植物的抗氧化酶系统活性和改善植物对光能的利用效率帮助植物抵御干旱胁迫,双因素方差分析结果显示接种AMF比施钾的效果更显著。

In current study, the influence of arbuscular mycorrhizal fungus （AMF） （Rhizophagus irregularis） inoculation and potassium application on growth, potassium content of different tissues, activities of antioxidative enzymes in leaf and the chlorophyll fluorescence parameters of Lycium barbarum responding to drought stress were assessed. The results showed that mycorrhizal colonization rates increased as the in- crease of potassium application under drought stress, growth and potassium content in roots and leaves of L. barbarum were improved by AMF and potassium application. Potassium application significantly increased the Fv/Fm ,ФPSⅡ ,ETR and decreased the qN of leaf under drought stress. Under drought stress, AMF significantly enhanced the Fv/Fm, ФPSⅡ , ETR,qP at different potassium levels, and significantly reduced the qN. The SOD, POD activities were enhanced significantly as the rise of potassium levels under drought stress, except for the CAT activity. The SOD, POD activities in leaves were only significantly improved by AMF at 2 mmol potassium level. Therefore,AMF and potassium application could help plants to resist drought stress by regulating nutrition status, increasing anti-oxidant enzymes activities and impro- ving light energy use efficiency,and the result of two-way ANOVA indicated that the effects of AMF were better than potassium application.