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The physiological basis of seed dormancy in Avena fatua III. Action of nitrogenous compounds
Author(s) -
Adkins Stephen W.,
Simpson Graham M.,
Naylor James M.
Publication year - 1984
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1984.tb04569.x
Subject(s) - avena fatua , dormancy , germination , gibberellin , nitrite , chemistry , horticulture , nitrate , biology , botany , organic chemistry
Sodium nitrate and nitrite (50–100 m M ) induced germination in three out of four genetically pure dormant lines of Avena fatua L. The sensitivity to these treatments was low immediately ater harvest and increased markedly after six months of dry after‐ripening. The observation that a fourth dormant line failed to respond suggests at least two metabolic blocks may be involved in expression of dormancy. An inhibitor of gibberellin biosynthesis, 2‐chloroethyl trimethylammonium chloride, completely inhibited the dormancy‐breaking effect by nitrate and nitrite, indicating a requirement for gibberellin biosynthesis. Among reduced nitrogenous compounds, ammonium chloride and urea failed to break dormancy in all partly after‐ripened lines, suggesting that nitrate and nitrite may induce germination through their ability to act as electron acceptors. The sensitivity to all nitrogenous compounds tested increased with the length of after‐ripening indicating that the depth of the second dormancy block amy decrease with the time of after‐ripening. Other reduced nitrogenous compounds, thiourea and hydroxylamine hydrochloride, promoted some germination in the least dormant, partially after‐ripened lines. The function of these compounds as electron acceptors and their similarity in activity to the cytochrome oxidase inhibitor, sodium azide, is discussed with reference to dormancy and the possible involvement of the alternative pathway of respiration.