2.4. Sugar, starch and protein determination
For starch, sugar and protein determinations, leaves
were dried overnight in a vacuum oven at 70 ◦C. Initial
trials showed thiswas the optimal temperature to ensure
no loss or breakdown of sugars, starches or proteins.
After drying, material was ground to a fine powder using
a mortar and pestle. Soluble sugars (glucose, fructose
and sucrose) were extracted using double distilled
water, clarified via the Carrez method to remove proteins
and measured using a Boehringer–Roche sugar
assay kit based on techniques developed by Bergmeyer
and Bernt (1974). Starch was solubilised from samples
using dimethylsulfoxide and hydrochloric acid as per
Boehringer-Mannheim (1984) and then assayed using
a Boehringer–Roche starch assay kit based on techniques
developed by Keppler and Decker (1974). Protein
was extracted using a SDS-based method (Pogson
and Morris, 1997) andwas then assayed using a protein
analytical kit (Bio-Rad) based on the Bradford method
(Bradford, 1976).
2.5. Statistics
All experimental trials were triplicated with 10, 15
or 20 replicates in each. Data shown in tables and
figures are from representative trials. All statistical
procedures were performed using Genstat (fourth edition)
(Rothamsted, UK). Least significant differences
(LSDs) were determined at P < 0.05 to compare means.
Covariate analysis was also performed using measurements
of lamina width, length and weight; petiole
width, thickness, length and weight; and leaf weight.
General regression equations (usually polynomial) of
GA during storage were used to calculate the storage
life of leaves (GA = 5.5). General regression equations
were also used to determine the degree of yellowing,
rots and physiological damage and the hue angle when
the GA was 5.5 (the end of storage life).
2.4. Sugar, starch and protein determinationFor starch, sugar and protein determinations, leaveswere dried overnight in a vacuum oven at 70 ◦C. Initialtrials showed thiswas the optimal temperature to ensureno loss or breakdown of sugars, starches or proteins.After drying, material was ground to a fine powder usinga mortar and pestle. Soluble sugars (glucose, fructoseand sucrose) were extracted using double distilledwater, clarified via the Carrez method to remove proteinsand measured using a Boehringer–Roche sugarassay kit based on techniques developed by Bergmeyerand Bernt (1974). Starch was solubilised from samplesusing dimethylsulfoxide and hydrochloric acid as perBoehringer-Mannheim (1984) and then assayed usinga Boehringer–Roche starch assay kit based on techniquesdeveloped by Keppler and Decker (1974). Proteinwas extracted using a SDS-based method (Pogsonand Morris, 1997) andwas then assayed using a proteinanalytical kit (Bio-Rad) based on the Bradford method(Bradford, 1976).2.5. StatisticsAll experimental trials were triplicated with 10, 15or 20 replicates in each. Data shown in tables andfigures are from representative trials. All statisticalprocedures were performed using Genstat (fourth edition)(Rothamsted, UK). Least significant differences(LSDs) were determined at P < 0.05 to compare means.Covariate analysis was also performed using measurementsof lamina width, length and weight; petiolewidth, thickness, length and weight; and leaf weight.General regression equations (usually polynomial) ofGA during storage were used to calculate the storagelife of leaves (GA = 5.5). General regression equationswere also used to determine the degree of yellowing,rots and physiological damage and the hue angle whenthe GA was 5.5 (the end of storage life).
การแปล กรุณารอสักครู่..