Dormancy of gladiolus corm. (III)

On the change of carbohydrate content and its relation to the dormancy

Abstract

There have been some papers on the chemical analysis of gladiolus corm, DENNY (1933), FAIRBURN (1934), LOOMIS (1934) and YASUDA.YOKOYAMA(19 55), but the relation between the chemical compo-sition and the germination percentage was not clear. This study was undertaken to find the relationship of the chemical composition to germination percen-tage.
The corms were planted early in February, and were dug up on Aug. 6, and Sept. 5, 1955. These corms were divided into three lots. Lot I was placed in a thermostat at a temperature of 35°C for 10 days and then placed into a refrigerator at a temperature of 2°C for 23_??_25 days. Lot II was placed in a refrigerator for 33_??_35 days, and lot III was used for control. These corms (var. Atom, Bo Peep, Jonquil, June Day, and White Gold) were planted immediately after the treatment, and their germination was recorded. This result was reported in the previous paper. Each of these sample was analyzed for wate content, starch and sugars before planting.
The result of chemical analysis is shown as fol-lows:
1. There was no difference in the water content of the corms in the three lots regardless of variety.
2. Reducing sugar content decreased during high temperature treatment, but increased after cold storage.
3. Non-reducing sugar increased during cold sto-rage. The amount of reducing sugar was propor-tionate to the germination percentage of the corms. The larger the amount of reducing sugar the higher was the germination percentage of corms for June Day and White Gold dug up. on Aug. 6, and for Atom, Bo Peep, June Day, and White Gold dug up on Sept. 5.
4. Starch decreased in inverse proportion to the increase of total sugar content during cold, storage.