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Effects of the triazole plant growth retardant BAS 111¨W on gibberellin levels in oilseed rape, Brassica napus
Author(s) -
Hedden P.,
Croker S. J.,
Rademacher W.,
Jung J.
Publication year - 1989
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.1399-3054.1989.tb05607.x
Subject(s) - shoot , brassica , gibberellin , cultivar , horticulture , sowing , gibberellic acid , chemistry , biology , botany , germination
Three‐week‐old shoots of the spring oilseed rape cv. Petranova ( Brassica napus L. ssp. napus ) were found by combined gas chromatography‐mass spectrometry to contain GA 1 , GA 8 , GA 15 , GA 17 , GA 19 , GA 20 , GA 24 , GA 29 , 3‐epi‐GA 1 and a previously uncharacterised C 19 dicarboxylic acid that is probably structurally related to GA 24 . Shoots of the winter cultivar Belinda, harvested at the early flowering stage, contained the same GAs with the exception of the C 19 dicarboxylic acid and, in addition, GA 34 and GA 51 were identified. All material contained higher levels of GA 20 than of GA 1 ; the ratio of GA 1 to GA 20 was highest in shoots containing the largest proportion of young immature tissues. Soil treatment of cv. Petranova seedlings with the growth retardant BAS 111¨W [1‐phenoxy‐5,5‐dimethyl‐3‐(1,2,4‐triazol‐1‐yl)‐hexan‐4‐ol] caused 80% reduction in height 18 days after treatment and the levels of all GAs were 20% or less that of control plants. Foliar treatment at the same dosage reduced height by 50% and caused an 85% or greater reduction in the concentrations of the GA 1 precursors GA 20 , GA 19 and GA 44 . However, the levels of GA 1 , GA 8 and GA 29 were affected to a much smaller extent. Foliar application of BAS 111¨W to cv. Belinda 1 month after sowing resulted in only a 20% height reduction at flowering, but no uniform decrease in the concentrations of endogenous GAs at this stage.