Articles
SEASONAL BIOENERGETIC CONSTRUCTION COSTS OF APPLE FRUITS, LEAVES AND SHOOTS
Article number
416_19
Pages
163 – 168
Language
Abstract
In modelling dry matter production of apple trees based on CO2 exchange, a conversion from grams of fixed CO2 or glucose to final dry matter is required.
This ratio is based on the bioenergetic construction costs for the different plant organs (e.g. organs with high levels of protein or lipids are more energetically costly than carbohydrate storage). To estimate the seasonal patterns of construction costs for apple fruits, leaves, young shoot stems and one-year-old wood, samples were taken at intervals during the season and dried.
The caloric values and nitrogen concentrations in the tissues were analyzed with a Carlo Erba analyzer.
Tissue glucose equivalents (GE = g of glucose required to produce 1 g of tissue) were estimated by the calculation method of Williams et al. (1987 – Plant Cell Environ. 10:725). In general, leaves had the greatest GE values, followed by young fruits, young shoot stems, one-year-old wood and mature fruits.
Seasonally, all organs tended to have the highest GE values early during active cell division growth and then declined over the season.
The fruit showed the greatest seasonal decline, while 1-year-old stem tissue showed little change over the season.
The declines were likely due to the accumulation of inexpensive carbohydrates during the mid- to late-season.
The GE values for the fruits were similar but somewhat lower than for kiwi berries, peaches and oranges reported in the literature.
Data on construction costs, combined with dry weight growth and respiration data, will allow more accurate estimation of bioenergetic costs and amounts of carbon fixation of growing apple fruits, leaves and shoots.
This ratio is based on the bioenergetic construction costs for the different plant organs (e.g. organs with high levels of protein or lipids are more energetically costly than carbohydrate storage). To estimate the seasonal patterns of construction costs for apple fruits, leaves, young shoot stems and one-year-old wood, samples were taken at intervals during the season and dried.
The caloric values and nitrogen concentrations in the tissues were analyzed with a Carlo Erba analyzer.
Tissue glucose equivalents (GE = g of glucose required to produce 1 g of tissue) were estimated by the calculation method of Williams et al. (1987 – Plant Cell Environ. 10:725). In general, leaves had the greatest GE values, followed by young fruits, young shoot stems, one-year-old wood and mature fruits.
Seasonally, all organs tended to have the highest GE values early during active cell division growth and then declined over the season.
The fruit showed the greatest seasonal decline, while 1-year-old stem tissue showed little change over the season.
The declines were likely due to the accumulation of inexpensive carbohydrates during the mid- to late-season.
The GE values for the fruits were similar but somewhat lower than for kiwi berries, peaches and oranges reported in the literature.
Data on construction costs, combined with dry weight growth and respiration data, will allow more accurate estimation of bioenergetic costs and amounts of carbon fixation of growing apple fruits, leaves and shoots.
Publication
Authors
A.N. Lakso, S.S. Denning
Keywords
Online Articles (37)