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Gibberellins and photoperiodic control of shoot elongation in Salix
Author(s) -
Junttila Olavi,
Jensen Einar
Publication year - 1988
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.1399-3054.1988.tb00645.x
Subject(s) - elongation , gibberellin , shoot , horticulture , botany , biology , chemistry , materials science , ultimate tensile strength , metallurgy
Effects of exogenous gibberellins GA 53 , GA 44 , GA 19 , GA 20 and GA 1 on photoperiodically controlled shoot elongation in seedlings of Salix pentandra L. were studied. Gibberellins GA 20 and GA 1 induced shoot elongation under short days (SD) and could substitute for a transfer to long day (LD), while gibberellins A 53 , A 44 and A 19 were inactive. In seedlings exposed to a prolonged SD‐treatment (30 days) there was a significant positive interaction between a transfer to LD and a treatment with GA 20 and GA 1 on shoot elongation. In addition, GA 19 enhanced the growth promotive effect of LD in these seedlings. The results are compatible with the suggestion that conversion of GA 19 to GA 20 is blocked under SD. This effect is supposed to be an early process leading to the cessation of shoot elongation under SD. Responsiveness of the seedlings to LD and to a GA‐treatment gradually decreased with an increasing length of exposure to SD.