|Authors: ||X.J. Min, D.P. Bartholomew|
We studied the effects of temperature on tissue ethylene production, ethylene forming enzyme (EFE) activity, forcing percentage, and fruit size of ‘Smooth Cayenne’ pineapple (Ananas comosus (L.) Merr.). Plants were grown at day/night temperatures of 30/30 and 30/20°C for 30 (Exp.1) or 51 (Exp.2) days.
Ethylene and EFE activity were measured on leaf basal-white and stem apical tissue of four plants prior to forcing by ethephon.
At forcing half the remaining plants were kept at the original temperatures and half were moved to the opposite temperature.
In both experiments, ethylene production and EFE activity of stem and leaf tissue of plants grown at 30/30°C were less than for plants grown at 30/20°C. After forcing, two of the six plants at 30/30°C produced an inflorescence-like structure lacking floral organs.
Some plants grown at 30/20°C and then moved to 30/30°C at forcing did not force.
Plants grown continuously at 30/30°C had only 13 (Exp.1) and 37 (Exp.2) fruitlets per fruit, while plants grown at 30/20°C had about 100 fruitlets per fruit in both experiments.
Plants grown at 30/30°C and transferred to 30/20°C after forcing had about 80 fruitlets per fruit.
Leaf titratable acidity of plants grown at 30/30°C was about 67% of that of plants grown at 30/20°C. Low ethylene production, EFE activity, and CO2 dark fixation may account in part for reduced flowering responses and lower fruit weights in environments having warm night temperatures.
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