Appenroth, K. J.; Hertel, W.; Augsten, H.
Author Affiliation :
Department of Biology-Plant Physiology, Friedrich Schiller University, Von-Hase-Weg 3, Jena 6900, Germany.
Abscisic acid secretion, ethephon production and oxygen deficiency were investigated as possible reasons why red-light-induced germination decreased as S. polyrhiza turions became more crowded in germination (Erlenmeyer) flasks. Although abscisic acid was a powerful inhibitor of turion germination it was excluded as a cause as it was not secreted from turions into nutrient solutions. Ethephon (Ethrel) at 10-7-10-3 smallcap˜M strongly inhibited the growth of newly formed sprouts, but not the germination response itself. Germination inhibition was not apparent if short light pulses were substituted by continuous irradiation. Inhibition occurred in the presence of 10-5 smallcap˜M of the photosynthesis inhibitor DCMU [diuron], but it was not observed in aerated nutrient solutions or when Petri dishes instead of Erlenmeyer flasks were used. Decreased oxygen concn were produced in nutrient solutions by turion respiration. It was therefore concluded that anaerobiosis caused by turion respiration was the reason for germination inhibition by overcrowding.
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Indexing terms for this abstract:
Organism descriptor(s) :
plants, Spirodela polyrhiza
Abscisic acid, aquatic organisms, aquatic plants, Aquatic weeds, biology, buds, Diuron, ecology, Ethephon, germination, growth, growth inhibitors, growth rate, herbicides, light, overcrowding, Plant growth regulators, respiration, weeds
(2-chloroethyl)phosphonic acid, ABA, aquatic species, DCMU, plant growth substances, plant hormones, weedicides, weedkillers
Broader term(s) :
eukaryotes, Spirodela, Araceae, Alismatales, monocotyledons, angiosperms, Spermatophyta, plants