干旱和盐胁迫对紫花苜蓿生理特性及品质的影响

Effect of drought and salt stress on endogenous osmotic substances of alfalfa

试验为明确干旱和盐复合胁迫对紫花苜蓿生理和品质的影响,以青大1号紫花苜蓿品种为试验材料,以不同浓度聚乙二醇(PEG-6000)(0、5%、10%、15%、20%)和NaCl浓度(0、0.5、1.0、1.5、2.0 g/L)为处理,探讨干旱和盐复合胁迫对青大1号紫花苜蓿的影响。结果显示,与对照组相比,干旱和盐胁迫对紫花苜蓿地上生物量有显著影响(P<0.05),株高、叶面积、鲜重、干重随着胁迫程度加深逐渐减小,干鲜比逐渐增大。当PEG-6000和NaCl浓度为0时,紫花苜蓿幼叶可溶性蛋白含量最高,为0.012μg/L;可溶性蛋白含量随着PEG-6000和NaCl浓度升高逐渐降低。脯氨酸含量随培养基溶液浓度升高呈逐渐上升趋势,最高为0.022μg/L。当PEG-6000和NaCl浓度分别为5%和0.5 g/L时,可溶性糖含量最高,为0.044μg/L。与对照组相比,N、P、K、Ca、Mg元素含量变化显著(P<0.05)。随着干旱和盐浓度的增加,N、P、K、Ca、Mg含量均维持较高水平,以抵御干旱和盐胁迫环境。干旱和盐胁迫对紫花苜蓿粗纤维和粗灰分有显著影响(P<0.05)。研究表明,紫花苜蓿通过生理特性变化以此适应干旱和盐复合胁迫,进而影响紫花苜蓿品质。

The experiment was to clarify the effect of combined drought and salt stress on physiology and quality of alfalfa, alfalfa variety Qingda No. 1 was treated with different NaCl concentrations(0, 0.5, 1.0, 1.5, 2.0 g/L) and polyethylene glycol(PEG-6000) concentrations(0, 5%, 10%, 15%, 20%) to explore the response of Qingda No.1 alfalfa variety to different concentrations of salt stress and reveal the mechanism of alfalfa drought resistance. The results showed that compared with the control group, drought and salt stress had significant effect in aboveground biomass of alfalfa(P<0.05), plant height, leaf area, fresh weight and dry weigh decreased gradually with the deepening of stress, and the dry fresh ratio increased gradually. When the concentration of PEG-6000 and NaCl was 0, the soluble protein content of alfalfa young leaves was the highest, which was 0.012 μg/L, and gradually decreased with the increase of PEG-6000 and NaCl concentration. The proline content increased gradually with the increase of medium concentration, and the highest was 0.022 μg/L. When the concentrations of PEG-6000 and NaCl were 5% and 0.5 g/L, respectively, the soluble sugar content was the highest, which was 0.044 μg/L. Compared with the control group, the content of N, P, K, Ca and Mg changed significantly(P<0.05). With the increase of drought and salt concentration, the content of N, P, K, Ca and Mg maintained at a high level to resist drought and salt stress environment. Drought and salt stress had an effect on crude fiber and crude ash content of alfalfa(P<0.05). The experiment indicates that alfalfa can adapt to drought and salt stress through physiological changes, affect the quality of alfalfa.