ISSN:
1432-2285
Keywords:
Larch
;
Larix
;
Phloem transport
;
Photoassimilate
;
Translocation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Young trees of Larix decidua, in their 4th and 5th year of development, were permitted to photoassimilate a pulse of 14CO2 at different times throughout the growing season. After chase periods between 1 h and 7 days, the distribution of 14C in these plants was determined. CO2 fixation followed a maximum curve with highest rates of photosynthesis of 123 ± 4 μmol CO2·h-1·mg chl-1 in June. Translocation of 14C assimilate was observed throughout the growing season. The main quantity of fixed 14C was always retained in the fed leaves. Radiocarbon moved basipetally into the roots at all times, particularly in spring and late summer. Sprouting young shoots and leaves at the stem apex attracted assimilate in spring. Incorporation of 14C into soluble low-molecular-weight substances prevailed; less radioactivity was incorporated into insoluble polymeric compounds. Distribution of 14C among the sugar, amino acid and organic acid fraction was determined. Labelled free sugars were analysed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00225352
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