Allelopathy is involved in the formation of pure colonies of the fern Gleichenia japonica

• Published in: Journal of plant physiology 2013-04, Vol.170 (6), p.577-582
• Main Authors: Kato-Noguchi, Hisashi, Saito, Yoshihumi, Ohno, Osamu, Suenaga, Kiyotake
• Format: Article
• Language: English
• Subjects: alfalfa; allelochemicals; Allelopathy; Biological activity; chemical structure; Chromatography, High Pressure Liquid; Colonies; Domination; Dose-Response Relationship, Drug; Echinochloa crus-galli; Ferns; Ferns - growth & development; Ferns - metabolism; ferns and fern allies; Gleichenia; Gleichenia japonica; Gleicheniaceae; Growth inhibitor; growth retardation; Inhibition; Japan; Lactuca sativa; Lepidium sativum; lettuce; Lettuces; Lolium multiflorum; Magnoliopsida - drug effects; Magnoliopsida - growth & development; Medicago sativa; methanol; Methyl alcohol; monitoring; Pheromones - chemistry; Pheromones - isolation & purification; Phleum pratense; plant communities; Plant Extracts - chemistry; Plant Extracts - isolation & purification; Plant Roots - drug effects; Plant Roots - growth & development; Plant Shoots - drug effects; Plant Shoots - growth & development; root growth; Roots; seedling growth; shoots; soil; Species Specificity; spectral analysis; Stands; Supports
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/j.jplph.2012.11.015

The fern Gleichenia japonica is one of the most widely distributed fern and occurs throughout East to South Asia. The species often dominates plant communities by forming large monospecific colonies. However, the potential mechanism for this domination has not yet been described. The objective of this study was to test the hypothesis that allelochemicals are involved in the formation of G. japonica colonies. An aqueous methanol extract of G. japonica inhibited the growth of seedlings of garden cress (Lepidium sativum), lettuce (Lactuca sativa), ryegrass (Lolium multiflorum) and timothy (Phleum pratense). Increasing extract concentration increased the inhibition. These results suggest that G. japonica contain allelopathic substances. The extract was then purified by several chromatographies with monitoring the inhibitory activity and two growth inhibitory substances causing the allelopathic effect were isolated. The chemical structures of the two substances were determined by spectral data to be a novel compound 3-O-β-allopyranosyl-13-O-β-fucopyranosyl-3β-hydroxymanool (1) and 18-O-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl-13-epitorreferol (2). These compounds inhibited the shoot and root growth of garden cress, lettuce, alfalfa (Medicago sativa), timothy, ryegrass and barnyardgrass (Echinochloa crus-galli) at concentrations greater than 0.1–1.0mM. The concentrations required for 50% growth inhibition of root and shoot growth of these test plants ranged from 0.72 to 3.49mM and 0.79 to 3.51mM for compounds 1 and 2, respectively. Concentration of compounds 1 and 2 in soil under the pure colony of G. japonica was 4.9 and 5.7mM, respectively, indicating concentrations over those required for 50% growth inhibition are potentially available under monocultural stands of these ferns. Therefore, these compounds may contribute to the allelopathic effects caused by presence of G. japonica and may thus contribute to the establishment of monocultural stands by this fern.