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Seed‐to‐seed allelopathic effects between two invaders of burned Pampa grasslands
Author(s) -
Laterra P,
Bazzalo M E
Publication year - 1999
Publication title -
weed research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 74
eISSN - 1365-3180
pISSN - 0043-1737
DOI - 10.1046/j.1365-3180.1999.00146.x
Subject(s) - germination , allelopathy , biology , seedling , leachate , weed , botany , horticulture , agronomy , ecology
The establishment of Lotus tenuis can interfere with colonization by Carduus acanthoides during the early post‐burn recovery of Flooding Pampa grasslands. The purpose of this research was to determine the potential role of L. tenuis seeds as a source of allelopathic compounds involved in that interaction. Imbibed seeds of L. tenuis and aqueous leachates from them were bioassayed for their ability to inhibit germination and seedling growth of C. acanthoides , both on sterilized filter paper and on pasteurized soil as substrata. Germination and/or emergence of C. acanthoides were inhibited and root length was reduced on filter paper or soil, by both the presence of L. tenuis seeds and their leachate, at densities of L. tenuis near the maximum values observed in the field. Germination and seedling growth of C. acanthoides were less affected by the presence of L. tenuis seeds than by the addition of their leachate, and the presence of L. tenuis seeds or their leachate showed stronger effects on emergence of C. acanthoides from soil than on its germination on filter paper. Methods applied for leachate sterilization, ultrafiltration or autoclaving did not modify C. acanthoides responses. Neither the germination rate nor the root length of C. acanthoides seedlings were affected by solutions of polyethylene glycol with similar osmolarity to the leachates. We conclude that the release of inhibitory substances on to filter paper and into pot soil from imbibed L. tenuis seeds would be the mechanism responsible for the observed effects.