ISSN:
1573-5087
Keywords:
Gibberellic acid
;
kinetin
;
2,4-D
;
Cucurbita seedlings
;
growth abnormalities
;
ethylene
;
ethephon
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Swelling of the hypocotyl base induced by 2,4-D in seedlings of marrow was much reduced if GA3 was also present in the incubation medium. At appropriate concentrations kinetin also counteracted this 2,4-D effect, although at higher concentrations appeared to be ineffective. GA3 was also able to overcome the inhibitory effects of 2,4-D on extension growth in the hypocotyl but kinetin was much less effective in this case. None of the treatments employed was able to alleviate the inhibition of radicle extension induced by 2,4-D. Ethephon induced similar responses in the seedlings to those resulting from 2,4-D treatment, while treatment with a mixture of 2,4-D and CoCl2 removed many of these growth abnormalities. These observations are interpreted as indicating that 2,4-D operates at least partly by stimulating the production of ethylene in the tissues. 2,4-D strongly inhibited the accumulation of endogenous gibberellin during the period of seedling development examined, but enhanced cytokinin levels during the later stages of the same period. The possibility of interactions at the biosynthetic level between gibberellins, cytokinins and ethylene and their involvement in the regulation of seedling development are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00024858
Permalink
