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Einfluß der N‐Düngung auf den 14 C‐Einbau in die Komponenten der äthanollöslichen Fraktion von Sommerweizen verschiedener Entwicklungsstadien
Author(s) -
Höfner W.,
Orlovius K.
Publication year - 1977
Publication title -
zeitschrift für pflanzenernährung und bodenkunde
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 0044-3263
DOI - 10.1002/jpln.19771400503
Subject(s) - chemistry , photosynthesis , amino acid , human fertilization , fraction (chemistry) , ripening , ethanol , solubility , botany , chromatography , biochemistry , food science , biology , organic chemistry , agronomy
Influence of N‐fertilization on the 14 C‐labelling of the ethanol soluble fraction and its components in spring wheat at different stages of development In spring wheat plants from pot experiments the effect of different N‐fertilization on the 14 C‐labelling of the soluble fractions of amino acids, organic acids, and carbohydrates was studied. The fraction of 14 C‐labelled compounds, soluble in ethanol, was 50% at the start of the experiment, about 100% during flowering stage and 45% at the end of the experiment. At the end of the 24h 14 CO 2 ‐assimilation period 90% of the activity in the plants were water soluble, carbohydrates containing 10 to 20 times higher 14 C‐activity than amino or organic acids. In plant labelled with 14 CO 2 during emergence of the ears, the solubility of 14 C‐labelled assimilates decreased till the ripening stage to 15% of the total 14 C‐activity, whereas the total activity itself decreased only to 50–80% during the same time. The higher N‐supply results in an enhanced decrease of soluble carbohydrates and in an increase of the soluble amino acid fraction. This leads also to an increased protein synthesis and 14 C‐assimilation into the protein of the kernels. The most important plant parts in respect to photosynthesis during the experiment period were upper leaves, upper stems and ears. The 14 C‐distribution throughout the plant is mainly determined by the time after 14 CO 2 ‐treatment and less by the N‐fertilization. This points to similar pathways of 14 CO 2 ‐assimilation in all trials. It is concluded, that the positive effect of the high N‐fertilization on the yield is due to the quick transformation of soluble assimilates into insoluble compounds, e.g. proteins and protein precursors. Increase of yield by high N‐fertilization is also due to a prolonged period of photosynthesis and therefore delayed ripening of the photosynthetic active plant parts.