牛叠肚幼苗对盐碱胁迫的生理响应机制研究

发布时间：2018-05-31 05:43

  本文选题：牛叠肚 + 单盐胁迫　； 参考：《沈阳农业大学》2016年博士论文

【摘要】：土壤盐碱化是影响农业生产以及生态环境的一个全球性问题。因此,如何改良和利用盐碱化土壤已成为亟待解决的重要课题。研究证实,在盐碱地引种经济型耐盐植物,是解决土壤盐碱化问题最有效的生物学措施之一。牛叠肚(Rubus crataegifolius Bge.)是我国东北地区广泛分布的野生果树资源,具有适应性强,耐寒、耐旱、滞尘能力强等优良特性,是果树育种、城镇园林绿化以及生态造林的良好经济树种。为了充分发掘该树种的资源优势,了解牛叠肚对盐碱胁迫的生理适应特性,本文以野生牛叠肚1a生组培苗为试材,盆栽模拟盐碱胁迫环境,分别研究了四种单盐(NaCl、Na2SO4、NaHCO3、 Na2CO3)和不同配比的混合盐胁迫对牛叠肚幼苗生长及生理指标的影响；探讨了牛叠肚幼苗抗氧化系统和渗透调节物质对单盐和混合盐胁迫的生理适应特性,并从离子的吸收、运输和分配角度阐述了牛叠肚的盐碱适应机制；通过统计学方法明确了盐碱混合胁迫对牛叠肚幼苗的主导作用因素。主要研究结果如下：1.牛叠肚幼苗生长在碱性盐(NaHCO3、Na2CO3)和碱性盐比例较低的混合盐(NaCl: Na2SO4:NaHCO3:Na2CO3=1:2:1:0, pH值8.24)处理下表现出“低促高抑”现象,而在中性盐(NaCl、Na2SO4)和其它配比的混合盐处理下其生长均受到不同程度的抑制；牛叠肚幼苗对NaCl、Na2SO4、NaHCO3、Na2CO3四种单盐的耐受阈值分别为85.18mmol·L-1(0.50%,w/v)、40.77 mmol·L-1(0.58%, w/v)、171.00 mmol·L-1(1.44%, w/v)、 114.20mmol·L-1 (1.21%, w/v)。2.单盐(NaCl、Na2SO4、NaHCO3、Na2CO3)胁迫和不同配比的混合盐胁迫处理下,牛叠肚幼苗叶片的相对电导率均随胁迫浓度的升高呈增加趋势,并且在高盐(≥120mmol.L-1)或高pH (NaCl:Na2SO4:NaHCO3:Na2CO3=9:1:1:9,pH值10.58)处理下,牛叠肚叶片的细胞膜透性遭到严重破坏。3. NaHCO3胁迫和不同配比的混合盐胁迫处理下的牛叠肚叶片丙二醛(MDA)含量均较对照增加或显著增加,而其它三种单盐处理下的MDA含量则呈间断累积。随胁迫浓度的增加,四种单盐胁迫处理下的牛叠肚叶片中超氧化物歧化酶(SOD)活性呈“先升高后下降”的趋势,而过氧化物酶(POD)活性则呈“先下降后升高”的趋势；不同配比的混合盐胁迫处理下,牛叠肚叶片中POD活性均显著增加,而SOD活性总体呈下降趋势。研究表明,在单盐胁迫下牛叠肚幼苗主要通过SOD和POD的互补作用来降低氧化伤害,而在盐碱混合胁迫下主要通过提高幼苗体内POD活性来减轻盐碱伤害,以维持植株正常生理代谢。4,单盐胁迫下,随着胁迫浓度的升高,牛叠肚幼苗叶片可溶性糖、游离脯氨酸、可溶性蛋白含量均呈不同幅度的增加；在一价单盐(NaCl、NaHCO3)胁迫处理下,牛叠肚幼苗主要通过可溶性糖、游离脯氨酸、可溶性蛋白的交替积累来发挥其渗透调节功能；在二价单盐(Na2SO4、Na2CO3)胁迫处理下,可溶性糖、游离脯氨酸和可溶性蛋白的积累趋势各异,其中,在Na2CO3胁迫条件下三者同步积累,共同发挥其渗透调节功能,而在Na2SO4胁迫处理下,牛叠肚幼苗主要通过可溶性糖和可溶性蛋白的彼此协同作用来降低盐碱伤害。盐碱混合盐胁迫下,牛叠肚叶片中可溶性糖和可溶性蛋白含量均随胁迫浓度的升高呈间断性积累,而游离脯氨酸含量先缓慢上升后急剧增加,在整个渗透调节过程中脯氨酸发挥着主导作用。5,单盐和混合盐胁迫处理下,牛叠肚幼苗根、茎、叶中的Na+含量均显著增加,而各器官中K+/Na+和Ca2+/Na+比值总体呈下降趋势,但叶片中K+/Na+和Ca2+/Na+始终保持相对较高比值,这对于维持叶片正常的生理功能具有重要意义；中性盐(NaCl、Na2SO4)和高浓度混合盐胁迫下,牛叠肚幼苗优先将Na+截留在茎部,而碱性盐(NaHCO3、 Na2CO3)胁迫下N+主要积累在茎和根中,叶中Na+含量始终处于较低水平,这可能是牛叠肚幼苗适应盐碱胁迫的一个重要途径。6.经多元回归分析表明,盐浓度、[C1]、pH值是牛叠肚盐碱混合胁迫的主导作用因素,可用株高生长量、相对电导率、丙二醛含量、叶绿素含量、可溶性糖含量、脯氨酸含量、可溶性蛋白含量、叶片中Na+、K=含量和K+/Na+比值等指标来评价牛叠肚的耐盐碱能力。
[Abstract]:Soil salinization is a global problem affecting agricultural production and ecological environment. Therefore, how to improve and utilize the salinized soil has become an important issue to be solved. It has been proved that the introduction of economic salt tolerant plants in saline alkali land is one of the most effective biological measures to solve the problem of soil salinization. Rubus crataeg Ifolius Bge. is a widely distributed wild fruit tree resource in Northeast China. It has the advantages of strong adaptability, cold tolerance, drought resistance and strong dust retention ability. It is a good economic tree for fruit tree breeding, urban landscaping and ecological afforestation. In order to fully explore the source advantage of this tree, the physiological adaptation of cattle tripe to saline alkali stress is understood. In this paper, the effects of four single salt (NaCl, Na2SO4, NaHCO3, Na2CO3) and mixed salt stress on the growth and physiological indexes of the young cattle were studied in the simulated saline alkali stress environment, and the antioxidant system and osmotic substances of the oxen seedlings were studied for single salt and mixed with 1a. The physiological adaptation of salt stress, and the salt alkali adaptation mechanism of ox tripe from the angle of ion absorption, transport and distribution, and the dominant factors of Salt Alkali Mixed stress to the tripe seedlings were clarified by statistical methods. The main results were as follows: 1. the seedling of 1. calf was grown in alkaline salt (Na2CO3) and alkaline salt ratio. The lower mixed salt (NaCl: Na2SO4:NaHCO3:Na2CO3=1:2:1:0, pH 8.24) showed a "low growth inhibition" phenomenon, while the growth of the neutral salt (NaCl, Na2SO4) and other mixed salts was inhibited in varying degrees. The tolerance threshold of the four single salt of NaCl, Na2SO4, NaHCO3 and Na2CO3 was 85., respectively. 18mmol L-1 (0.50%, w/v), 40.77 mmol. L-1 (0.58%, w/v), 171 mmol. L-1 (1.44%, w/v), 114.20mmol. L-1 (1.21%, w/v) stress and mixed salt stress treatment, the relative conductivity of the leaf slices of the bovine tripe seedlings increased with the increase of stress concentration. Under the treatment of mol.L-1) or high pH (NaCl:Na2SO4:NaHCO3:Na2CO3=9:1:1:9, pH 10.58), the cell membrane permeability of the leaves of bovine tripe was severely damaged by.3. NaHCO3 stress and mixed salt stress of different proportions, the content of malondialdehyde (MDA) in the leaf of cattle was increased or significantly increased, while the MDA content under the other three single salt treatments was increased. With the increase of stress concentration, the activity of superoxide dismutase (SOD) in the leaves of cattle tripe under four single salt stress treatments was "first increased and then descended", while the activity of peroxidase (POD) was "decreased first and then increased", and the activity of POD in the leaves of bovine tripe under the mixed salt stress treatment was all under the mixed salt stress treatment. The results showed that the activity of SOD decreased in general. The study showed that under the stress of single salt, the oxidative damage was reduced by the complementation of SOD and POD, and under the mixed stress of salt and alkali, the POD activity of the seedlings was mainly improved to reduce the salt alkali damage, and the normal physiological metabolism of the plant was.4, with the single salt stress, with the stress of the single salt stress. The content of soluble sugar, free proline and soluble protein in the leaves of bovine tripe seedlings increased in different ranges. Under the stress treatment of single salt (NaCl, NaHCO3), the seedlings of bovine tripe were mainly composed of soluble sugar, free proline and soluble egg white to play its osmotic regulation function in the two price list. Under the stress treatment of salt (Na2SO4, Na2CO3), the accumulation trend of soluble sugar, free proline and soluble protein was different. In the condition of Na2CO3 stress, the three people accumulated and played the function of osmotic regulation together. Under the stress of Na2SO4 stress, the seedlings of bovine tripe were mainly reduced to each other by the synergism of soluble sugar and soluble protein. Under the stress of salt alkali mixed salt, the content of soluble sugar and soluble protein in the leaves of cattle tripe showed intermittent accumulation with the increase of stress concentration, while the free proline content increased slowly and then increased rapidly. In the whole process of osmotic regulation, proline played a leading role of.5, under the stress of single salt and mixed salt, the cattle were stacked. The content of Na+ in root, stem and leaf of the seedlings increased significantly, while the ratio of K+/Na+ and Ca2+/Na+ in all organs decreased, but the ratio of K+/Na+ and Ca2+/Na+ in leaves remained relatively high, which was of great significance for maintaining the normal physiological function of leaves. Under the stress of neutral salt (NaCl, Na2SO4) and high concentration of mixed salt, the cattle were folded young. Miao Youxian intercepted Na+ in the stem, while alkaline salt (NaHCO3, Na2CO3) stressed that N+ accumulated mainly in the stem and root, and the Na+ content in the leaves was always at a low level. This may be an important way to adapt to salt stress in the seedlings of bovine tripe..6. through multivariate regression analysis showed that the concentration of salt, [C1], and pH are the leading role of the mixed salt stress of calf. The salt tolerance of cattle was evaluated by factors such as plant height growth, relative electrical conductivity, content of malondialdehyde, chlorophyll content, soluble sugar content, proline content, soluble protein content, Na+, K= content and K+/Na+ ratio in leaves.
【学位授予单位】：沈阳农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S567.19
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本文编号：1958516