Rhizobacteria facilitate physiological and biochemical drought tolerance of Halimodendron halodendron (Pall.) Voss

Growth-promoting bacteria(GPB)have shown promising effects on serving plants against environmental constraints such as drought.Nevertheless,simultaneous effects of different GPB have less been considered for arid land plants and under field conditions.We investigated the effects of single and combined application of GPB,including free-living nitrogen-fixing bacteria(NFB),phosphate solubilizing bacteria(PSB),potassium solubilizing bacteria(KSB),a combination of NFB,PSB,and KSB(NPK),and control,at three drought stress treatments.In order to better understand the interactions between drought and GPB,we measured the morphological,biochemical,and physiological plant traits.The target plant was salt tree(Halimodendron Halodendron(Pall.)Voss),a legume shrub native to arid lands of Central and West Asia.All biofertilizer treatments enhanced the growth,physiology,and biochemistry of salt tree seedlings,and there were significant differences among the treatments.KSB and PSB treatments increased photosynthetic pigments,but KSB treatment was more efficient in transpiration rate and stomatal regulation and increased the soluble carbohydrates.PSB treatment had the highest effect on root traits,such as taproot length,root volume,cumulative root length,and the ratio of root to shoot.NFB treatment enhanced root diameter and induced biomass translocation between root systems.However,only the application of mixed biofertilizer(i.e.,NPK treatment)was the most significant treatment to improve all plant morphological and physiological characteristics of salt tree under drought stress.Therefore,our results provided improvement of some specific plant traits simultaneous with application of three biofertilizers to increase growth and establishment of salt tree seedlings in the degraded arid lands.

响应面法优选铃铛刺花蕾多糖提取工艺

目的采用响应面法优选铃铛刺花蕾多糖的最佳提取工艺。方法以铃铛刺花蕾多糖得率为评价指标,对提取温度、液料比及提取时间进行单因素实验,根据Box-Behnken实验结果,采用响应面法验对铃铛刺花蕾多糖提取工艺进行优化。结果铃铛刺花蕾多糖最佳提取工艺为:提取温度73℃,液料比42∶1(mL/g),提取时间2.1 h,此条件下铃铛刺花蕾多糖得率可达8.64%。结论本实验操作简单,稳定性好,适用于铃铛刺花蕾多糖的提取。

铃铛刺花中多糖的含量测定

目的建立测定铃铛刺花提取物中多糖含量的方法。方法采用水提-醇沉法提取铃铛刺花中的粗多糖,以葡萄糖为标准品,采用苯酚-硫酸法测定多糖的含量。结果对照品在0.010 28~0.072 02mg/mL浓度范围内线性关系良好,平均加样回收率为100.7%,RSD=1.19%(n=6),铃铛刺花提取物中多糖含量为0.125 5mg/g。结论本方法简便,操作性强,重复性好,适用于测定铃铛刺花提取物中多糖的含量。

铃铛刺花提取物中总黄酮含量测定

目的:建立一种测定铃铛刺花提取物中总黄酮的方法。方法:采用紫外分光光度法,以芦丁作为对照品,在500nm波长下测定吸光度,建立标准曲线,并计算铃铛刺花提取物中总黄酮的含量。结果:芦丁对照品在0.040 2~0.803 2mg/mL浓度范围内线性关系良好,平均加样回收率为100.49%(RSD=2.62%,n=9),铃铛刺花提取物中总黄酮平均含量为5.5%。结论:该方法准确、简便、重复性好,可用于铃铛刺花提取物中总黄酮的含量测定,为其质量控制提供了有效的方法。

盐旱胁迫下铃铛刺种子萌发特性

以呼和浩特地区引种的铃铛刺种子为试材,采用不同浓度的NaCl溶液(4、8、12、16、20 g·L^(-1))和PEG-6000溶液(5%、10%、15%、20%、25%)模拟盐旱胁迫方法,研究盐旱胁迫下铃铛刺种子的萌发特性,以期为铃铛刺在干旱半干旱地区用于改良盐碱土及生态修复提供参考依据。结果表明:随盐胁迫程度的增大,铃铛刺种子的萌发率、萌发势呈先上升后下降的趋势,萌发指数、活力指数、胚根胚芽长随NaCl浓度的升高呈下降趋势;干旱胁迫下,各指标均随PEG-6000溶液浓度的升高而降低,低浓度(5%)对种子萌发抑制作用不明显;NaCl溶液和PEG-6000溶液浓度分别为20 g·L^(-1)和25%时,铃铛刺种子的萌发率为54.67%和25.33%,未达到完全抑制其萌发的盐旱阈值,经引种的铃铛刺种子在萌发期仍具有较高的耐盐、耐旱特性。