松嫩盐碱草地星星草根围AM真菌多样性及功能研究

发布时间：2018-06-02 17:30

本文选题：星星草 + AM真菌　；参考：《东北林业大学》2017年硕士论文

【摘要】：丛枝菌根真菌(arbusculr mycorrhizal fungi,AMF)是一类分布最广泛、最普遍的土壤微生物,能与90%以上的植物形成互利互惠的共生体——菌根结构。逆境条件下,AM真菌通过促进植物对矿质营养元素的吸收利用、维持植物渗透调节能力、增加植物对水份的吸收、改善植物生理代谢,从而减轻逆境对植物的伤害,因而在环境修复中的应用受到广大环境工作者的关注。星星草是一种具有较强耐盐能力的优质牧草,本论文以肇东市松嫩盐碱草地采集的星星草(Puccinellia tenuiflora)根系及其根际土壤为试验材料,对星星草根际AM真菌的多样性和侵染特性进行了初步调查研究,分离并运用形态学和分子生物学结合的方法鉴定出星星草根际的优势AM真菌菌株,并在此基础上进一步通过接种试验,验证这两种优势AM真菌对星星草耐盐碱性的影响。旨在为筛选耐盐碱AM真菌菌种,进而为利用菌根技术进一步提高星星草的耐盐碱能力,促进星星草在松嫩盐碱草地修复中的应用和在盐碱地区的园林绿化提供重要理论依据。试验结果如下:1.本试验于2015年7月在黑龙江省肇东市西南部松嫩盐碱草地采集了9份星星草根系和根际土壤,在土壤pH值为最低值8.35和最高值9.81时,侵染率分别为80%和40%,侵染密度分别为15.60%和19.20%。在土壤pH值为9.72时,侵染率达到最大值93.33%,侵染密度达到30%,在土壤pH为9.50时泡囊丰度和侵染密度达到最大值,分别为13.31%和30.87%。土壤pH为9.59时泡囊丰度和侵染密度达到最小值,分别为0.05%和4.30%。2.通过形态学鉴定出来的AM真菌共11属40种,其中球囊霉属(Glomus)为优势属,共14种,占总数的35%,是优势属;盾巨孢囊霉属(Scutellospora)、和平囊霉属(Pacispora)、多样孢囊霉属(Diversispora)、Claroideoglomus以及Racocetra属各一种,占总数的2.5%;摩西管柄囊霉(Funneliformis mosseae)和根内根生囊霉(Rhizophagus intraradices)是分离鉴定出的优势种,重要值分别为61.53%和64.58%。通过形态学和分子生物学结合的方法鉴定出摩西管柄囊霉(F.mosseae)、根内根生囊霉(R.intraradices)、幼套近明囊霉(Claroideoglomus etunicatum)和一种通过形态鉴定无法确定的AM真菌,测序结果在NCBI得到序列接收号分别是KU376499、KT881238、KU144882和KT952460。3.接种摩西管柄囊霉(FM)和根内根生囊霉(RI)的星星草在生长80d后均与AM真菌形成良好的共生体系,且侵染程度都比较高,FM和RI侵染率分别为:80.86%和85.91%。之后进行不同的NaCl浓度和NaHCO3浓度胁迫处理10d,试验研究表明,在不同浓度盐碱胁迫下,星星草对AM真菌都有较高的菌根依赖性,对RI尤其显著,在盐浓度处理达到400mmol/L时,MD值高达300.25%,侵染等级达到Ⅲ级。4.由于星星草自身的耐盐碱特性,低浓度的盐碱处理浓度反而促进其生长发育,随着NaCl或NaHCO3胁迫浓度的增大,星星草长势消弱,但接种AM真菌的星星草植株比未接种植株的耐盐碱能力显著较高,能够减少脯氨酸和丙二醛含量;降低相对电导率,从而维持稳定的细胞膜透性;增加可溶性蛋白含量以及提高对N、P、K离子的吸收能力;无论对于对照组还是NaCl或NaHCO3处理组,在同一处理水平下,接种植株根际土壤脲酶、蔗糖酶和过氧化氢活性明显比未接种植株的活性高。其中这种改善作用在盐或碱浓度为200mmol/L时最为显著(p0.05)。
[Abstract]:Arbusculr mycorrhizal fungi (AMF) is the most widely distributed, most common soil microorganism, which can form a symbiotic symbiont with more than 90% plants - mycorrhizal structure. Under adverse conditions, AM fungi promote plant osmotic regulation and increase plants by promoting the absorption and utilization of plants to mineral nutrients. The absorption of water and the improvement of plant physiological metabolism, thus reducing the harm of adversity to plants, has been paid attention to by environmental workers. The rhizosphere soil was used as the experimental material to investigate the diversity and infection characteristics of AM fungi in the rhizosphere of the stellar grass. The dominant AM fungal strains were identified by the method of combining morphology and molecular biology to identify the dominant AM fungi in the rhizosphere of the star grass. On this basis, the two dominant AM fungi were validated against the stars. The effect of salt and alkaline resistance of stellar grass is aimed at screening salt tolerant AM fungi, and further improving the salt and alkali resistance of stellar grass with mycorrhiza technology, promoting the application of star grass in the restoration of saline alkali grassland and afforestation in saline alkali areas. The experimental results are as follows: 1. the experiment was in black in July 2015. 9 roots and rhizosphere soils were collected in the saline alkali grassland of Songnen, Zhaodong, Longjiang province. When the soil pH value was 8.35 and the maximum value was 9.81, the infection rate was 80% and 40% respectively. The infection density was 15.60% and the pH value was 9.72, the infection rate reached the maximum value 93.33%, the infection density reached 30%, and the soil pH was 9.5. At 0, the abundance of vesicle and infection density reached the maximum, and the abundances and infection density reached the minimum when the pH of the soil was 9.59, respectively, and the AM fungi were identified by 0.05% and 4.30%.2., respectively, 11 genera and 40 species, of which Glomus was the dominant genus, and 14 species, accounting for 35% of the total, were the dominant genera, giant spores of shield. Scutellospora, Pacispora, Diversispora, Claroideoglomus, and Racocetra are one of the various species, accounting for 2.5% of the total. The dominant species are identified as Funneliformis mosseae and Rhizophagus intraradices (Rhizophagus intraradices), and the important values are 61.53% and 64.58%., respectively. A combination of morphological and molecular biology methods was used to identify F.mosseae, R.intraradices, Claroideoglomus etunicatum and a AM fungus that could not be identified by morphological identification. The sequence results were KU376499, KT881238, KU144882 and KT952 respectively in NCBI. 460.3. inoculated with 460.3. (FM) and root cysts (RI) formed a good symbiotic system with AM fungi after the growth of 80D, and the degree of infection was higher. The FM and RI infection rates were respectively: 80.86% and 85.91%., the concentration of NaCl and NaHCO3 concentration stress were 10d. The experimental study showed that the concentration of salt was in different concentration of salt. Under alkali stress, the AM fungi have high mycorrhizal dependence on the mycorrhizal fungi, especially for the RI. When the salt concentration reaches 400mmol/L, the MD value is up to 300.25%. The infection grade reaches to grade III.4. due to the salt tolerance of the star grass itself. The low concentration of saline alkali treatment promotes its growth and development, with the concentration of NaCl or NaHCO3 stress. In addition, the growth of P. mendens was weakened, but the salt and alkali resistance of the plants inoculated with AM fungi was significantly higher than that of the uninoculated plants, reducing the content of proline and malondialdehyde, reducing the relative conductivity, maintaining the stable cell membrane permeability, increasing the soluble protein content and improving the absorptive capacity of N, P, and K ions, no matter to the control. Group NaCl or NaHCO3 treatment group, under the same treatment level, inoculation of rhizosphere soil urease, invertase and hydrogen peroxide activity was significantly higher than that of uninoculated plants at the same level of treatment. The improvement effect was most significant when salt or alkali concentration was 200mmol/L (P0.05).
【学位授予单位】：东北林业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S154.3

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