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Allelochemical autotoxicity in the emergent wetland macrophyte Juncus effusus (Juncaceae)
Author(s) -
Ervin Gary N.,
Wetzel Robert G.
Publication year - 2000
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.2307/2656893
Subject(s) - juncus , biology , seedling , shoot , botany , scirpus , allelopathy , bioassay , germination , ecology , wetland
Bioassays for allelochemical toxicity of aboveground Juncus effusus tissues were conducted with seeds and seedlings of Eleocharis obtusa and Scirpus cyperinus , two emergent sedge species (Cyperaceae) found sympatric with J. effusus , and with seeds and seedlings of J. effusus itself to evaluate potential autotoxicity. Bioassays were performed under controlled, axenic conditions with aqueous shoot extract treatments simulating in situ dissolved organic carbon concentrations. With respect to the two sedge species, neither shoot development nor seedling biomass accrual was significantly suppressed by lyophilized whole extracts from J. effusus. Although the extracts induced no significant reduction in growth of E. obtusa or S. cyperinus , biomass‐specific chlorophyll a concentration was significantly reduced in E. obtusa seedlings. In contrast, seedlings of J. effusus exhibited significant reductions of biomass and chlorophyll a concentrations, and seedling shoot development was retarded in response to leachate exposure. Results of the present study suggest that J. effusus seedlings possess autotoxic sensitivity to extracts of dead, aboveground tissues of adult plants.