Microbial communities of Pyrenophora-infested wheat straw as examined by multivariate analysis

• Published in: Microbial ecology Vol. 15; no. 1; pp. 95 - 113
• Main Authors: Pfender, W.F, Wootke, S.L
• Format: Journal Article
• Language: English
• Published: New York, NY Springer-Verlag New York Inc 1988; Springer
• Subjects: Actinomycetes; Agronomy; Animal, plant and microbial ecology; Bacteria; Biological and medical sciences; Biological control; Biotechnology; CELLULOLYTIC MICROORGANISMS; Control; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fungi; Habitats; Industrial applications and implications. Economical aspects; Microbial ecology; MICROORGANISME; MICROORGANISMOS; MICROORGANISMS; Ordination; PAILLE DE BLE; PAJA DE TRIGO; Phytopathology. Animal pests. Plant and forest protection; PYRENOPHORA; Pyrenophora tritici-repentis; Soil fungi; Soil microorganisms; Straw; Triticum aestivum; Various environments (extraatmospheric space, air, water); WHEAT STRAW; Microorganism interrelationships; Vegetals; Microflora; Identification; Phytopathogen; Multivariate analysis; Septoria nodorum; Straw; Fungi; Enzymatic activity; Conservation tillage; Pyrenophora tritici-repentis; Ascomycetes; Fungi Imperfecti; Antagonist; Wheat; Thallophyta
• ISSN: 0095-3628; 1432-184X
• DOI: 10.1007/BF02012954

Winter wheat straw naturally infested with Pyrenophora triticirepentis and Septoria nodorum was incubated in the field in one of three placements: buried in the soil, placed directly on the soil surface, or placed 2 cm above the soil within a straw layer. Periodically between June and April, straws from each treatment were collected and assayed by dilution plating to determine microbial populations in the following categories: total yeasts, total actinomycetes, total other bacteria, and genera or species of fungi. The data were analyzed by the multivariate procedures of ordination and classification, using detrended correspondence analysis (DCA) and cluster analysis, respectively. The major DCA axis displayed a gradient starting with pioneer colonizer communities of above-soil straw (dominated by Pyrenophora, Septoria, Alternaria, and Cladosporium), through on-soil straws (colonized by secondary saprophytes such as Acremonium strictum, Diplodia, Fusarium, and bacteria) to buried straws (dominated by actinomycetes, bacteria, and soil-inhabiting fungi). The second DCA axis showed a gradient separating different types of late secondary communities. In vitro tests for degradative abilities of straw-inhabiting organisms showed that low-temperature cellulolysis is characteristic of pioneer and early secondary colonizers, whereas chitin degradation is limited to secondary colonizers, particularly soil inhabitants. The results suggest the vulnerability of Pyrenophora and Septoria to displacement by secondary colonists in an active microbial community, and indicate a number of organisms that may be useful in biological control of these plant parasites through exploitative or interference competition in plant residues.