锰胁迫下外生菌根真菌对土壤磷钾的活化利用

发布时间：2018-05-06 17:05

本文选题：锰 + 磷　；参考：《西南大学》2017年硕士论文

【摘要】：全球林地面积的60%甚至更多为酸性土壤。锰(Mn)是酸性土壤上仅次于铝的危害因素。酸性土壤Mn毒、缺磷和缺钾并存,外生菌根真菌(ECMF)抗(耐)Mn和利用土壤磷钾的能力对树木适应酸土环境、提高森林生产力、植树造林和治理Mn污染有重要意义。论文采用液体培养方法,在培养液中加入不同浓度的Mn,以大白菇Rd(Russula delica Fr.)、彩色豆马勃Pt 715(Pisolithus tinctorius 715)、土生空团菌Cg(Cenococcum geophilum Fr.)和厚环粘盖牛肝菌Sg[Suillus grevillei(Kl.)Sing]等ECMF为供试菌种(株),研究了Mn对ECMF生长、养分吸收、有机酸和氢离子(H~+)分泌的影响,以及Mn在菌丝中的分布。并在Mn胁迫条件下,以土壤为磷钾源,研究了ECMF生长、有机酸和H~+分泌,及对土壤磷钾活化利用作用等,主要研究结果如下:1.不同菌种(株)对Mn的敏感程度不同。在Mn胁迫时,ECMF的抗(耐)Mn能力为RdSgPt 715Cg;Rd和Pt 715的解磷能力强于Cg;Rd和Pt 715的解钾能力优于Cg和Sg,由此可见,南方菌株Rd和Pt 715比北方菌株更适应高Mn、低磷和缺钾多重胁迫的生长环境。2.ECMF菌丝内,Mn绝大部份存在于质外体,少量进入细胞内,前者是后者的5.23~9.21倍,说明原生质膜是外生菌根真菌防御Mn进入细胞的重要屏障。3.Mn胁迫条件下,ECMF的磷含量和吸收量增加,菌种(株)表现呈多样性。在减轻Mn毒的过程中,菌丝体内磷酸盐(或聚磷酸盐)对Mn固定作用有利于ECMF拮抗Mn毒。4.Mn胁迫条件下,抗性较强的Rd和Sg分泌H~+的速率显著降低,菌丝和原生质的Mn含量也显著低于敏感性菌株,说明降低Mn的活性和减少吸收有益于ECMF抗(耐)Mn。5.Mn胁迫条件下,ECMF分泌的有机酸种类和数量因菌种(株)不同而异。ECMF均能分泌草酸,抗Mn性强的菌种(株)分泌草酸较多,抗性差者则较少。草酸对Mn2+、Fe2/3+和Al2/3+等的络合作用有益于降低外源有效Mn浓度,减轻毒害,活化土壤矿物中的磷钾养分。6.Mn胁迫条件下,以土壤为磷源,ECMF能有效吸收极低浓度的外源磷(0.007~0.027 mg/L),供试菌种(株)均能降低土壤中的铝磷、铁磷和闭蓄态磷。对抗Mn性较强的菌种(Rd和Pt 715)而言,Mn对土壤无机磷总量的降幅无显著影响;但对敏感的Cg来说,土壤无机磷总量的降幅显著减少。说明Mn抑制Mn敏感型ECMF活化利用土壤无机磷。7.含Mn的培养液中,Rd、Pt 715和Cg的钾含量和吸收量高于无Mn处理,在土壤水溶性钾≤1.48 mg/kg时,ECMF仍能有效吸收钾离子;培养ECMF后,土壤水溶性钾、交换性钾和缓效钾总量较原始土壤低,其降幅远低于ECMF的吸收量。因此,在Mn胁迫条件下,ECMF活化利用土壤矿物中的钾。此外,适量的Mn促进Rd、Pt 715和Cg活化利用土壤矿物结构钾,但在培养液中添加Mn则抑制Sg活化利用矿物结构钾。8.Mn胁迫条件下,以土壤为钾源,随着Mn浓度的增大,ECMF的H~+分泌量、吸钾量和土壤矿物结构钾的降幅增加,说明适量的Mn刺激ECMF分泌H~+,分解含钾矿物,促进钾吸收。总之,ECMF对Mn的抗(耐)性因菌种(株)不同而异,菌丝细胞膜是Mn进入细胞物理屏障;在Mn胁迫条件下,ECMF通过调节磷吸收,有机酸(尤其是草酸)和H~+分泌拮抗Mn毒;Mn不同程度影响ECMF活化利用土壤难溶性无机磷及矿物结构钾,ECMF对于树木适应Mn毒、缺磷和缺钾并存的酸性土壤有潜在作用。
[Abstract]:60% or more of the global woodland area is acid soil. Manganese (Mn) is a hazard only to aluminum in acid soil. Acid soil Mn poison, phosphorus deficiency and potassium deficiency coexist. The ability of exogenous mycorrhizal fungi (ECMF) to resist (tolerance) Mn and use soil phosphorus and potassium is important for trees to adapt to the acid soil environment, improve forest productivity, planting trees and harnessing Mn pollution. In this paper, the liquid culture method was used to add different concentrations of Mn in the culture solution, including the Rd (Russula Delica Fr.), the color bean Pt 715 (Pisolithus tinctorius 715), the Cg (Cenococcum geophilum Fr.) and the thick ring of the Boletus. The effects of ECMF growth, nutrient absorption, the secretion of organic acids and hydrogen ions (H~+) and the distribution of Mn in the mycelia. And under the condition of Mn stress, the growth of ECMF, the secretion of organic acids and H~+, and the activation and utilization of phosphorus and potassium in soil were studied under the condition of Mn stress. The main results were as follows: 1. the sensitivity of different strains to Mn was different. In Mn stress, the ability of ECMF to resist (resistant) Mn is RdSgPt 715Cg, Rd and Pt 715 is stronger than Cg, and Rd and Pt 715 are better than Cg and Sg. In the cell, the former is the 5.23~9.21 times of the latter, indicating that the protoplast membrane is an important barrier of the ectomycorrhizal fungi to defend the Mn into the cells. Under the condition of.3.Mn stress, the phosphorus content and absorption of ECMF are increased, and the strain (strain) shows diversity. In the process of reducing Mn toxicity, the immobilization of phosphate (or polyphosphate) to Mn in the mycelium is beneficial to the antagonism of ECMF. Under the stress of anti Mn virus.4.Mn, the rate of Rd and Sg secreting H~+ was significantly reduced, and the Mn content of mycelia and protoplasm was also significantly lower than that of the sensitive strain. It indicated that the reduction of the activity of Mn and the reduction of absorption were beneficial to ECMF resistance (resistant) Mn.5.Mn stress, and the species and quantity of organic acids secreted by ECMF were all different for the strain (strain). The secretion of oxalic acid and Mn resistant strains secrete more oxalic acid and less resistance. The complexation effect of oxalic acid on Mn2+, Fe2/3+ and Al2/3+ is beneficial to reduce the concentration of effective Mn, reduce the toxicity, and activate the phosphorus and potassium nutrients in the soil mineral, under the condition of.6.Mn stress, soil soil is the phosphorus source, and ECMF can effectively absorb the extremely low concentration of exogenous phosphorus (0 7~0.027 mg/L), the test strain (strain) could reduce the amount of Al P, Fe, P and P in soil. Against Mn strong strains (Rd and Pt 715), Mn had no significant effect on the decrease of total inorganic phosphorus in soil, but to the sensitive Cg, the decrease of the total amount of inorganic phosphorus in the soil decreased significantly. It showed that Mn inhibited Mn sensitive ECMF activation and utilization of soil. The potassium content and absorption of Rd, Pt 715 and Cg were higher than that of no Mn in the medium phosphorus.7. containing Mn. ECMF still could absorb potassium ions effectively when soil water-soluble potassium was less than 1.48 mg/kg; after culture ECMF, the soil water-soluble potassium, exchangeable potassium and slow available potassium were lower than those of the original soil, and the decline was much lower than the absorption of ECMF. Therefore, the condition of Mn stress was under the condition of Mn stress. In addition, ECMF activates potassium in soil minerals. In addition, appropriate amount of Mn promotes Rd, Pt 715 and Cg activation and utilization of soil mineral structure potassium, but the addition of Mn in the medium inhibits Sg activation using mineral structure potassium.8.Mn stress, and the soil is potassium source, with the increase of Mn concentration, ECMF H~+ secretion, potassium uptake and soil mineral potassium. The decline increased, indicating that a proper amount of Mn stimulated ECMF to secrete H~+, decompose potassium containing minerals and promote potassium absorption. In a word, the anti (tolerance) resistance of ECMF to Mn varies with the strain (strain). The mycelial membrane is Mn into the cell physical barrier; under Mn stress, ECMF regulates phosphorus absorption, organic acids (especially oxalic acid) and H~+ secrete Mn toxicity; Mn is different degrees. ECMF can activate the utilization of soil insoluble inorganic phosphorus and mineral structure potassium, and ECMF has potential effects on trees adapting to Mn toxicity, Phosphorus Deficient and potassium deficient coexisting acidic soil.

【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S714.6

【参考文献】