Interactions of arbuscular-mycorrhizal fungi and Bacillus strains and their effects on plant growth,microbial rhizosphere activity (thymidine and leucine incorporation) and fungal biomass (ergosterol and chitin) |
| |
| Institution: | 1. Departamento de Microbiolog??a del Suelo y Sistemas Simbióticos, Estación Experimental del Zaid??n, CSIC, Profesor Albareda 1, 18008 Granada, Spain;2. Departamento de Ciencias Ambientales y Recursos Naturales, Facultad de Ciencias Experimentales y de la Salud Universidad San Pablo CEU, 28668 Boadilla del Monte, Madrid, Spain;1. Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558, Republic of Singapore;2. Energy Study Institute, National University of Singapore, 29 Heng Mui Keng Terrace, Singapore, 119620, Republic of Singapore;3. NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, Singapore, 138602, Republic of Singapore;1. Laboratoire Biotechnologie et Physiologie Végétale, Faculté des Sciences Semlalia, Université Cadi Ayyad, Marrakech, Morocco;2. Faculté des Sciences et Technique Errachidia, Equipe Protection, Amélioration et Ecophysiologie Végétales, Université My Ismail Meknès, Morocco;3. Wilaya Région Marrakech, Service de l’Environnement, Marrakech, Morocco;4. School of Science and Engineering, Al Akhawayn University in Ifrane, BP: 1846, Ifrane, Morocco;5. Laboratoire Ecologie et Environnement (L2E) (Unité Associée au CNRST, URAC32, Unité associée au CNERS), Faculté des Sciences Semlalia, Université Cadi Ayyad, Marrakech, Morocco;1. Forestry Sciences Laboratory, USDA Forest Service, Northern Research Station, 410 MacInnes Dr, Houghton, MI, 49931, USA;2. Soil Biology Group, Wageningen University and Research, Droevendaalsesteeg 3, NL-6708 PB, Wageningen, Netherlands;3. Department of Life Sciences, Imperial College London, London, SW7 2AZ, England, UK;4. Comparative Plant & Fungal Biology, Royal Botanic Gardens, Kew, Richmond, TW9 3DS, England, UK;5. Earth Systems Research Center, University of New Hampshire, 8 College Road, Durham, NH, 03824-0322, USA;1. Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Portici, Italy;2. Department of Plant Propagation, Leibniz-Institute of Vegetable and Ornamental Crops, Kühnhäuser Straße 101, 99090 Erfurt, Germany;3. INOQ GmbH, Solkau 2, 29465 Schnega, Germany;4. Leibniz Institute of Vegetable and Ornamental Crops, Theodor Echtermeyer Weg 1, 14979 Großbeeren, Germany;5. Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy;6. Italpollina S.p.A., 37010 Rivoli Veronese, Italy;7. Department of Agriculture, Forestry, Nature and Energy, University of Tuscia, 01100 Viterbo, Italy |
| |
| Abstract: | The effects of two Bacillus strains (Bacillus pumillus and B. licheniformis) on Medicago sativa plants were determined in single or dual inoculation with three arbuscular-mycorrhizal (AM) fungi and compared to P-fertilization. Shoot and root plant biomass, values of thymidine and leucine incorporation as well as ergosterol and chitin in rhizosphere soil were evaluated to estimate metabolic activity and fungal biomass, respectively, according to inoculation treatments. For most of the plant parameters determined, the effectiveness of AM fungal species was influenced by the bacterial strain associated. Dual inoculation of Bacillus spp. and AM fungi did not always significantly increase shoot biomass compared to single AM-colonized plants. The most efficient treatment in terms of dry matter production was the dual Glomus deserticola plus B. pumillus inoculation, which produced similar shoot biomass and longer roots than P-fertilization and a 715% (shoot) and 190% (root length) increase over uninoculated control. The mycorrhizas were more important for N use-efficiency than for P use-efficiency, which suggests a direct mycorrhizal effect on N nutrition not mediated by P uptake. Both chemical and biological treatments affected thymidine and leucine incorporation in the rhizosphere soil differently. Thymidine was greater in inoculated than in control rhizospheres and B. licheniformis was more effective than B. pumillus in increasing thymidine. Non-inoculated rhizospheres showed the lowest thymidine and leucine values, which shows that indigenous rhizosphere bacteria increased with introduced inocula. The highest thymidine and leucine values found in P-fertilized soils indicate that AM plants are better adapted to compete with saprophytic soil bacteria for nutrients than P-amended plants. Chitin was only increased by coinoculation of B. licheniformis and G. intraradices. B. pumillus increased ergosterol (indicative of active saprophyte fungal populations) in the rhizosphere of AM plants and particularly when colonized by G. mosseae. The different AM fungi have different effects on bacterial and/or fungal saprophytic populations and for each AM fungus, this effect was specifically stimulated or reduced by the same bacterium. This is an indication of ecological compatibilities between microorganisms. Particular Glomus–bacterium interactions (in terms of effect on plant growth responses or rhizosphere population) do not seem to be related to the percentage of AM colonization. The effect on plant growth and stimulation of rhizosphere populations, as a consequence of selected microbial groups, may be decisive for the plant establishment under limiting soil conditions. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
