Requena N, Jimenez I, Toro M, Barea J M
Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Profesor Albareda 1, 18008 Granada, Spain.
New Phytol. 1997 Aug;136(4):667-677. doi: 10.1046/j.1469-8137.1997.00786.x.
Arbuscular mycorrhizal (AM) fungi, Rhizobium bacteria and plant-growth-promoting rhizobacteria (PGPR) were isolated from a representative area of a desertified semi-arid ecosystem in the south-east of Spain. Microbial isolates were characterized and screened for effectiveness by a single-inoculation trial in soil microcosms. Anthyllis cytisoides L., a mycotrophic pioneer legume, dominant in the target mediterranean ecosystem, was the test plant. Several microbial cultures from existing collections were also included in the screening process. Two AM fungi (Glomus coronatum, native, and Glomus intraradices. exotic), two Rhizobium bacteria (NR4 and NR9, both native) and two PGPR (A2, native, and E, exotic) were selected. A further screening for the appropriate double and triple combinations of microbial inoculants was then performed. The parameters evaluated were biomass accumulation and allocation, N and P uptake, N -fixation ( N) and specific root length. Overall, G. coronatum, native in the field site was more effective than the exotic G. intraradices in co-inoculation treatments. In general, our results support the importance of physiological and genetic adaptation of microbes to the whole environment, thus local isolates must be involved. Many microbial combinations were effective in improving either plant development, nutrient uptake, N -fixation or root system quality. Selective and specific functional compatibility relationships in plant response between the microbial inoculants, were observed. Despite the difficulty of selecting a multifunctional microbial inoculum, appropriate microbial combinations can be recommended for a given biotechnological input related to improvement of plant performance. This could be exploited in nursery production of target plant species endowed with optimized rhizosphere/mycorrhizosphere systems that can be tailored to help plants to establish and survive in nutrient-deficient, degraded habitats. The relevance of this microbial-based approach in the context of a reclamation strategy addressed to environmental sustainability purposes is discussed.
从西班牙东南部一个沙漠化半干旱生态系统的典型区域分离出丛枝菌根（AM）真菌、根瘤菌和促植物生长根际细菌（PGPR）。通过在土壤微观环境中的单接种试验对微生物分离株进行表征和有效性筛选。目标地中海生态系统中占主导地位的菌根先锋豆科植物——岩生扁蓿豆（Anthyllis cytisoides L.）作为受试植物。筛选过程中还纳入了现有菌种保藏库中的几种微生物培养物。挑选出两种AM真菌（本土的冠球囊霉（Glomus coronatum）和外来的根内球囊霉（Glomus intraradices））、两种根瘤菌（均为本土的NR4和NR9）以及两种PGPR（本土的A2和外来的E）。随后对微生物接种剂的合适双重和三重组合进行了进一步筛选。评估的参数包括生物量积累与分配、氮和磷吸收、固氮（N）以及比根长。总体而言，在共接种处理中，田间本土的冠球囊霉比外来的根内球囊霉更有效。一般来说，我们的结果支持微生物对整个环境进行生理和遗传适应的重要性，因此必须纳入本地分离株。许多微生物组合在改善植物生长发育、养分吸收、固氮或根系质量方面有效。观察到微生物接种剂之间在植物反应方面存在选择性和特定的功能兼容性关系。尽管难以选择多功能微生物接种剂，但对于与改善植物性能相关的特定生物技术投入，可以推荐合适的微生物组合。这可用于目标植物物种的苗圃生产，构建优化的根际/菌根际系统，以帮助植物在养分缺乏、退化的生境中定植和存活。本文讨论了这种基于微生物的方法在以环境可持续性为目标的复垦策略中的相关性。
