AM 真菌生物技术促进小马鞍羊蹄甲幼苗生长的应用研究
文献类型：学位论文
| 作者 | 张亚敏 |
| 学位类别 | 硕士 |
| 答辩日期 | 2016-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 曲来叶 |
| 关键词 | 岷江干旱河谷 Arid valley of Minjiang River 小马鞍羊蹄甲 Bauhinia faberi var． microphylla 丛枝菌根真菌 Arbuscular mycorrhizal fungi 干旱胁迫 Drought stress 植被恢复 Vegetation restoration |
| 其他题名 | Application of AM fungi biotechnology for the growth of Bauhinia faberi var．microphylla seedlings |
| 学位专业 | 生物工程 |
| 中文摘要 | 岷江干旱河谷区干旱、缺水，是植被恢复十分困难的地段。植被的生长受到土壤水分和土壤养分的共同制约。一直以来的干旱河谷植被恢复工作主要是植树造林，但是效果甚微，甚至发现整地造林多年后岷江柏造林不仅没有达到岷江干旱河谷预期的生态恢复重建效果，反而有加剧生态退化的趋势。本研究所选的小马鞍羊蹄甲（Bauhinia faberi var．microphylla）这种灌木不仅是岷江上游干旱河谷旱生灌丛优势种和广布种，对区域生态环境的维护起着不可替代的作用，有希望成为缺水和贫瘠的山地生态环境中植被恢复与重建植物选择上的理想材料。而丛枝菌根真菌（arbuscular mycorrhizal fungi, AMF）是菌根真菌中重要的一种类型，广泛分布于自然界的土壤中，能够与陆地上大约80%的植物根系形成互利共生关系，促进植物对P 和N 元素的吸收，以及水分的吸收，并且共生关系在环境胁迫的条件下表现的更为紧密。 基于AM 真菌在干旱贫瘠土壤中的重要特性，本研究采用水分控制实验，在三种干旱胁迫条件下，定量化研究不同AM 真菌对优势乡土植物小马鞍羊蹄甲幼苗生长的影响；采用高通量测序的方法，分析在不同干旱胁迫条件下，接种野外根际菌落的幼苗最终共生的AM 真菌种类及其组成；在这些结果基础之上，探讨菌根生物技术在岷江干旱河谷植被恢复过程中的应用，以期为岷江干旱河谷植被恢复提供了理论依据。 本论文得到的主要研究结果如下： （1）在干旱胁迫条件下，水分抑制了小马鞍羊蹄甲幼苗的生长，而接种AM真菌到小马鞍羊蹄甲幼苗根系显著促进了幼苗的生长。AM 真菌能够与小马鞍羊蹄甲形成良好的共生关系，侵染率达71.43%—97.34%。接种AM 真菌提高了幼苗的最大光合速率、水分利用效率；显著提高了相对生长速率、根生物量、茎生物量、叶生物量、总生物量、株高、叶片数、叶面积、分枝数、根总长、根表面积、根体积、根分枝数、根尖数（P<0.001）；显著促进了地上部分及根系的N/P/K元素吸收（P<0.001），特别是对P 元素的吸收；显著降低了根冠比，降低了根系拓扑指数；但对比叶面积、比根长等功能性指标没有显著影响。 （2）在干旱胁迫条件下，小马鞍羊蹄甲幼苗接种摩西球囊霉菌（Glomus mosseae）和野外根际菌落（Field soil）的效果不同。接种摩西球囊霉菌的幼苗菌根侵染率、丛枝丰度、相对生长速率、根生物量、茎生物量、叶生物量、总生物量、株高、叶片数、叶面积、分枝数、最大光合速率、根总长、根表面积、根体积、根分枝数、根尖数、地上地下N/P/K 吸收总量均高于接种野外根际菌落。在水分轻度胁迫时，接种摩西球囊霉菌的菌根侵染率、丛枝丰度、相对生长速率、根生物量、茎生物量、叶生物量、总生物量、叶片数、叶面积、分枝数、根总长、根表面积、根体积、根分枝数、根尖数、地上K 吸收总量、地下N 吸收总量显 著高于接种野外根际菌落（P<0.05）。并且接种摩西球囊霉菌的菌根效应高于接种野外根际菌落，在重度胁迫时差异显著。摩西球囊霉菌接种效果优于野外根际菌落。 （3）AM 真菌—植物根系共生系统促进小马鞍羊蹄甲幼苗生长的效果受水分的调控作用。随着干旱胁迫从重度到轻度（水分从低到高），AM 真菌在生长初期对幼苗地上地下的促生作用增强。特别地，在中度胁迫（土壤含水量为60%田间持水量）时，接种AM 真菌的幼苗P 元素百分含量达到最高。 （4）不同环境水分条件对AM 真菌具有筛选过滤的作用。三种干旱胁迫条件下，AM 真菌的OTU 丰富度、Shannon 多样性指数、Simpson 多样性指数及Pielou均匀度指数均不存在显著性差异（P>0.05）。其中重度胁迫时OUT 丰富度最低，多样性最高。侵染后的AM 真菌也是Glomus 属最多，这种在胁迫条件下形成的相对最适的植物—AM 真菌共生系统能够最大程度地促进植物对土壤水分及养分等限制性资源的获取。 综上所述，在干旱胁迫条件下由于接种AM 真菌与小马鞍羊蹄甲形成的共生关系能够帮助寄主植物显著缓解干旱的胁迫，促进植物生物量累积、养分吸收、改变植物碳分配模式，表明了AM 真菌在干旱环境中对小马鞍羊蹄甲生长中的重要作用。而摩西球囊霉作为小马鞍羊蹄甲根系优势的AM 真菌，能够在一定程度上提高植物的抗旱性，促进幼苗生长，菌根效应显著，这可能由于当地土壤中磷元素的极度缺乏有关。并且，随着干旱胁迫程度从重度到轻度（水分从低到高），形成共生的AM 真菌类群中，球囊菌属（Glomus）所占的比例大幅增加，优势凸显，因而球囊霉属的AM 真菌在小马鞍羊蹄甲复过程中具有重要的作用。虽然接种野外根系土壤没有单一接种摩西球囊霉菌的菌根效应显著，但考虑到节约成本，减少无机肥的使用，保持生态系统平衡和稳定等方面，该接种方式也具有重要的应用价值。虽然AM 真菌与小马鞍羊蹄甲的共生互利关系受到水分的调控，但本研究证明了接种AM 真菌的生物技术在干旱河谷植被恢复的应用具有相当大的可行性。 |
| 英文摘要 | The arid valley of Minjiang River area, where is very drought and lack of water,is one of the most difficult vegetation restoration areas. Among all the factors, soil moisture and soil nutrients constrain Vegetation the growth development of plants in arid valley. In the past years, vegetation restoration practices were mainly afforestation, but not very successful at all. For example, the rehabilitation with Cupressus chengiana not only did not meet our expectations of ecological restoration in Minjiang River area, but also there was an increasing trend of ecological degradation. Bauhinia faberi var. microphylla is a native perennial shrub of arid valleys, which is often predominant on eroded slopes and plays a vital role in retaining ecological stability in this region. It’s an ideal material choice for ecological environment revegetation in dry and barren areas. Arbuscular mycorrhizal fungi (AMF) is an important and common type of mycorrhizal fungi, which is widely distributed in worldwide soil. AM fungi can develop a symbiotic relationship with the roots of most terrestrial plants (80% ).By this mutually beneficial symbiotic relationship, AM fungi can enhance host plants uptake of P and N elements and AMF improve the resistance of host plants to drought stress. Previous research shows that the symbiotic relationship between AM fungi and host plant formed more closely under environmental stress conditions. Based on the above charcateristics of AM fungi, we designed a full factorial and completely random pot experiment in a greenhouse. Under three drought stress conditions and research effects of different AM fungi on the advantage native plant—B. faberi seedlings’ growth quantitatively. We also analysis the AM fungi species and community that inoculated B. faberi seedlings by wild field soil with high-throughput sequencing method under different drought stress conditions. At last, we investigate the application of mycorrhiza biotechnology in arid valley of Minjiang River vegetation restoration process on the basis of these results. We hope this knowledge would provide a theoretical basis for the vegetation restorationin arid valley of theMinjiang River. Our main results are as followed: (1) Under drought stress conditions, available water limited the growth of B.faberi seedlings. However, inoculated with AM fungi could significantly promote the growth of seedlings. AM fungi formed a good symbiotic relationship with B. faberi seedlings. Infection ratio was 71.43%-97.34%. Inoculated B. faberi seedlingshave higher maximum photosynthetic rate and water use efficienc.AM fungi significantly increased the relative growth rate, root dry biomass, stem dry biomass, leaf dry biomass, total dry biomass, plant height, leaf number, leaf area, number of branches,total root length, root surface area, root volume, root branches, number of tips (P<0.001).Inoculated by AM fungi significantly promoted the shoots’ and roots’ N / P /K elements absorption(P<0.001), especially promoted P element absorption. AM fungi also significantly reduced shoot:root and the root topological index. However, AM fungi didn’t significantly affect functional characteristics such as specific leaf area, and specific root length. (2) Under drought stress conditions, different AM fungi(Glomus mosseae and Field soil) have different effects on B. faberi seedlings. The B. faberi seedlings inoculated by G. mosseae had higher infection ratio, arbuscular abundance, relative growth rate, root dry biomass, stem dry biomass, leaf dry biomass, total dry biomass,plant height, leaf number, leaf area, number of branches, maximum photosynthetic rate, total root length, root surface area, root volume, root branches, the number of root tips, shoot and root N / P / K content than the B. faberi seedlings inoculated by Field soil which obtain all kinds of AM fungi. Specially, under the high water treatment (80% field capacity), The B. faberi seedlings inoculated by G. mosseae had significantly higher infection frequency, arbuscular abundance, relative growth rate,root dry biomass, stem dry biomass, leaf dry biomass, total dry biomass, leaf number , leaf area, number of branches, total root length, root surface area, root volume, root branches, the number of root tips, the shoot K content, the root N content than the B. faberi seedlings inoculated by Field soil (P<0.05). And the former had higher mycorrhizal growth response.When low drought stress(40% field capacity), the B.faberi seedlings inoculated by G. mosseae had significantly higher mycorrhizal growth response. (3) AM fungi - plant root symbiotic system promoted the growth of B. faberi seedlings. Meanwhile this progress effected by water treatments. With drought stress from severe to mild (from low water to high water), AM fungi promoted the growth of B. faberi seedlings more in the early seedling growth. In particular, under middle drought stress(60% field capacity), inoculated B. faberi seedlings had the highest P percentage concentration. (4) Water conditions had a choice of AM fungi. Under three drought stress conditions, OTU richness, Shannon diversity index, Simpson diversity index and Pielou evenness index all had no significant difference (P> 0.05). Under low drought stress(40% field capacity), OTU richness was minimum while diversity was maximum. Glomus genus is always the most advantage AM fungi. AM fungi - plant root developed relatively optimal symbiotic system under drought stress conditions,whichis beneficial for the promotion of nutrients, water and other restricted resources. In summary, B. faberi seedlings could significantly relieve the drought stress and infertile soil conditions by inoculated with AM fungi, such as promoting biomass allocation, nutrient uptakes, changing carbon partitioning pattern. These results demonstrated the important role of AM fungi for the growth and rehabilitation of B. faberi. The dominated AM fungi, G. mosseae significantly promote the growth of seedlings, which may due to the phosphorous deficiency of this region , and the symbiotic relationship with B. faberi seedlings was mediated by water conditions. The Glomus of forest soil inoculation became much more dominated with increasing water levels. According to saving the cost of labor, the fertilizer and keeping the stability of soil ecosystem, the applying of forest soil as the inocular in the future rehabilitation practices still should be considered although the symbiotic relationship was controlled by available soil water in this semi-arid region. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/37056]  |
| 专题 | 生态环境研究中心_城市与区域生态国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 张亚敏. AM 真菌生物技术促进小马鞍羊蹄甲幼苗生长的应用研究[D]. 北京. 中国科学院研究生院. 2016. |
入库方式： OAI收割
来源：生态环境研究中心
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