Allelopathic and bioherbicidal potential of Cladonia verticillaris on the germination and growth of Lactuca sativa

• Published in: Ecotoxicology and environmental safety 2012-10, Vol.84, p.125-132
• Main Authors: Tigre, R.C., Silva, N.H., Santos, M.G., Honda, N.K., Falcão, E.P.S., Pereira, E.C.
• Format: Article
• Language: English
• Subjects: acetone; acids; allelochemicals; Allelopathy; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Biological Control Agents; Cladonia; Complex Mixtures - pharmacology; Ecotoxicology, biological effects of pollution; ethers; Fumarprotocetraric acid; Fundamental and applied biological sciences. Psychology; General aspects; germination; Germination - drug effects; high performance liquid chromatography; Lactuca - drug effects; Lactuca - growth & development; Lactuca sativa; leaf area; lettuce; Lichen; Natural herbicide; Parmotrema; Plant Leaves - drug effects; Protocetraric acid; root growth; roots; Saccharomycetales - chemistry; seedlings; seeds; Seeds - drug effects
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2012.06.026

Responses to germination and initial growth of Lactuca sativa (lettuce) submitted to organic extracts and purified compounds of Cladonia verticillaris (“salambaia”) were analyzed in this work. The experiments were conducted in laboratory conditions using extracts and pure compounds at different concentrations. None of the assays showed any influence on the germination of L. sativa seeds using C. verticillaris extracts; however, modifications in leaf area and seedling hypocotyl and root development occurred. In the growth experiments, seedlings exposed to ether or acetone extract showed diminished hypocotyl growth in detriment to the root stimulus, compared to controls. Increases in extract concentrations led to the formation of abnormal seedlings. To determine the allelochemicals of C. verticillaris, its principal components, fumarprotocetraric and protocetraric acids, were isolated and then analyzed by high performance liquid chromatography (HPLC). When the seedlings were exposed to the two acids separately, presented increased leaf area at all concentrations. In contrast, hypocotyl and root stimulus was observed only in the presence of protocetraric acid at different concentrations. Fumarprotocetraric as well as protocetraric acids, isolated and purified from C. verticillaris and Parmotrema dilatatum respectively, influenced the development of L. sativa seedlings at high concentrations, indicating a possible bioherbicide potential of these acids. [Display omitted] ► FUM and PRO at all concentrations increased leaf area of Lactuca sativa ► Stimulation of hypocotyl and root occurs only in the presence of acid protocetraric. ► Extracts and compounds of C. verticillaris influenced the development of L. sativa. ► C. verticillaris has potential for bioherbicide studies.