四种灌木对盐碱胁迫的生理响应及其对土壤主要肥力指标的影响

发布时间：2018-01-15 17:38

本文关键词：四种灌木对盐碱胁迫的生理响应及其对土壤主要肥力指标的影响　出处：《宁夏大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着宁夏地区土地盐碱化日趋严重,耕地资源的紧缺,土地盐碱化已严重制约了农业的发展,改良和利用盐碱地成为了我们研究的主要方向。盐碱土的改良是一个长期而复杂的工程,其核心是降低土壤有害盐分含量,改善土壤环境使其适应植物生长,提高作物产量。目前,在众多改良方法中利用耐盐植物改良盐碱土被认为是最高效持久的解决办法。本文以不同浓度NaCl和NaHCO3胁迫下的黑果枸杞、沙棘、银水牛果、柽柳为试验材料,将耐盐植物、土壤和微生物视为一个整体进行系统性研究,分析植物对不同浓度的盐碱胁迫的生理响应,植物对盐分的吸收、运移,植物对盐碱土壤化学性质和养分的影响,以及土壤微生物功能多样性等的研究。得出以下结论:(1)不同浓度NaCl和NaHCO3胁迫对植物的生长发育、光合特性都会产生不同程度的影响;比较四种植物在不同种类盐胁迫下生长及其光合特性的变化和下降幅度,NaHCO3胁迫对沙棘、银水牛果和柽柳的盐害程度高于NaCl胁迫,而NaHCO3胁迫对而黑果枸杞的盐害程度低于NaCl胁迫。综合分析可得四种植物耐盐碱性比较为:黑果枸杞柽柳银水牛果沙棘。(2)植物可以从土壤中吸收毒害性最强的Na+并通过茎转移至地上部分,起到土壤脱盐的作用。四种植物中黑果枸杞的吸收能力最强,Na+在整株植物的累积量达到100mg/100g,其次是柽柳,沙棘和银水牛果的效果不显著。随着胁迫的持续和盐分浓度的递增,植物体内离子含量的积累和转运发生了变化,根系通过增加K+/Na+提高对胁迫的适应性,并由根系将毒性离子转移至地上部分,地上部分Na+增加K+含量降低。地下部分恰好相反,所以植物的茎叶是储存Na+的主要组织。(3)种植耐盐植物对土壤有机质和无机营养元素都有明显的影响,四种植物作用下有机质含量明显增加,土壤的全氮、全磷、全钾都有不同程度提高。随着胁迫强度的增加土壤各营养元素呈下降的趋势,在碱胁迫下土壤各营养元素含量低于同等浓度的盐胁迫。随着时间的增长营养元素含量整体水平上升,其中柽柳的效果最为显著,所以耐盐植物可有效的提高盐碱土壤的肥力,对盐碱土壤有改良作用。(4)在盐碱胁迫下,黑果枸杞和柽柳的根区微生物活性高于对照,但随着胁迫强度的增加有所下降。沙棘和银水牛果结果则与之相反。植物根区土壤微生物功能多样性与土壤全氮、全磷存在极显著正相关关系。综上所述,种植耐盐植物具有对盐碱土盐分的主动吸收、运移的作用,对土壤化学性质、微生物功能多样性的改善和提升作用,因此,本试验的研究结果对宁夏盐碱地改良改良技术体系具有重要的补充和支撑作用。
[Abstract]:With the increasingly serious land salinization and the shortage of cultivated land resources in Ningxia, land salinization has seriously restricted the development of agriculture. The improvement of saline-alkali soil is a long-term and complex project, the core of which is to reduce soil harmful salt content and improve soil environment to adapt to plant growth. To increase crop yields. Using salt-tolerant plants to improve saline-alkali soil is considered to be the most effective and lasting solution among many improved methods. Black fruit wolfberry seabuckthorn and silver buffalo under different concentrations of NaCl and NaHCO3 stress were used in this paper. The salt-tolerant plants, soil and microorganisms were regarded as a whole to study systematically the physiological response of plants to different concentrations of saline-alkali stress, and the absorption and migration of salt to plants. Effects of plants on chemical properties and nutrients of saline-alkali soils. The following conclusions are drawn: (1) different concentrations of NaCl and NaHCO3 stress have different effects on plant growth and photosynthesis. The changes of growth and photosynthetic characteristics of four plants under different salt stress and the decreasing extent of NaHCO3 stress on seabuckthorn, silver buffalo fruit and Tamarix were higher than those under NaCl stress. The salt tolerance of four plants under NaHCO3 stress was lower than that of NaCl stress. The results showed that the salt tolerance of four species of plants was: Tamarix chinensis, Tamarix chinensis, Silver buffalo fruit Hippophae rhamnoides (Rhizoma rhamnoides). Plants can absorb the most toxic Na from the soil and transfer it to the aboveground part through the stem. In the four plants, the absorption capacity of Lycium barbarum was the strongest, and the accumulation of Na in the whole plant was 100 mg / 100 g, followed by Tamarix chinensis. The effect of Hippophae rhamnoides and Silver Buffalo fruit was not significant. The accumulation and transport of ions in plants changed with the increasing of salt concentration and stress. Root system increased the adaptability to stress by increasing K / Na, and transferred toxic ions to the aboveground part by root. The Na content in the aboveground part increased and decreased, but in the underground part, the contrary. Therefore, plant stem and leaf is the main tissue of Na storage.) Salt tolerant plants have obvious effects on soil organic matter and inorganic nutrients, and the content of organic matter increases obviously under the action of four plants. Soil total nitrogen, total phosphorus, total potassium increased in varying degrees. With the increase of stress intensity, the soil nutrient elements showed a downward trend. Under alkali stress, the content of nutrient elements in soil was lower than that of salt stress of the same concentration. With the increase of time, the overall level of nutrient element content increased, and the effect of Tamarix chinensis was the most significant. Therefore, salt-tolerant plants can effectively improve the fertility of saline-alkali soil, and improve the saline-alkali soil. 4) under salt and alkali stress, the microbial activity in root zone of Lycium barbarum and Tamarix chinensis is higher than that of control. But with the increase of stress intensity, the results of seabuckthorn and silver buffalo fruit were opposite. There was a very significant positive correlation between soil microbial function diversity and soil total nitrogen and total phosphorus in plant root zone. Planting salt-tolerant plants has the function of active absorption and migration of salt in saline-alkali soil, and the improvement and promotion of soil chemical properties and microbial functional diversity. The research results of this experiment have important supplement and support function to the technical system of improving saline-alkali land in Ningxia.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q945.78;S158

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