Translocation and distribution of photosynthates in ‘Delaware’ grapes

Distribution of photosynthates from leaves into different plant parts was studied in potted 2-year-old ‘Delaware’ grape which were exposed to 14CO2 at different stages of berry development. In the first experiment, shoots, trunks, roots, berries and leaves were sampled 6, 24 and 72 hours after 14CO2 feeding and the 14C activities in the ethanol soluble and insoluble fractions were measured. In the second experiment, each ethanol soluble fraction of shoots, berries and leaves being sampled 6 hours after 14CO2 feeding was separated into individual compounds by paper and column chromatography, and the 14C activities were then estimated. The results are summarized as follow1. 14C in the ethanol soluble and insoluble fractions in leaves decreased with time after 14CO2 feeding. The 14C labelled photosynthates translocated from leaves into shoots, trunks and roots increased in the ethanol insoluble fraction 24 and 72 hours after feeding, but did not increase in the ethanol soluble fraction.2. The amount of 14C translocated into berries increased at Stage I and III, and appeared mostly in the ethanol soluble fraction in both stages.3. In seeds, more 14C was found in the ethanol insoluble fraction than in the ethanol soluble fraction, and the incorporation ratio increased in the course of berry development from Stage I to Stage II.4. In leaves and shoots, the 14C incorporated into the sugar fraction was mainly found in sucrose, glucose and fructose, and that in the organic acid fraction was mainly in malic acid and tartaric acid. In berries, the distribution of 14C into sugar and organic acid fractions was similar to that in leaves and shoots, except for sucrose. However, the 14C distribution ratio varied at different stages of berry development.

[1]  P. Hansen.  14C-Studies on Apple Trees. VI. The Influence of the Fruit on the Photosynthesis of the Leaves, and the Relative Photosynthetic Yields of Fruits and Leaves , 1970 .

[2]  J. D. Quinlan,et al.  Influence of Benzyladenine, Leaf Darkening, and Ringing on Movement of C-labeled Assimilates Into Expanded Leaves of Vitis vinifera L. , 1969, Plant physiology.

[3]  P. Hansen.  14C‐Studies on Apple Trees. II. Distribution of Photosynthates from Top and Base Leaves from Extension Shoots , 1967 .

[4]  C. R. Hale,et al.  The effect of developmental stage on direction of translocation of photosynthate in Vitis vinifera , 1962 .

[5]  R. Cory,et al.  Demonstration of Two Translocation Mechanisms in Studies of Bidirectional Movement. , 1960, Plant physiology.

[6]  F. Lee,et al.  Chemical Changes Accompanying Growth and Development of Seed and Fruit of the Elberta Peach , 1942, Botanical Gazette.

[7]  Hitoshi Tanaka,et al.  Studies on the Translocation of Photosynthates in Satsuma Orange I. Effect of Summer Cycle Shoot and Bearing Fruit on the Translocation and Distribution of 14 C , 1972 .

[8]  P. Hansen.  14C‐Studies on Apple Trees. IV. Photosynthate Consumption in Fruits in Relation to the Leaf‐Fruit Ratio and to the Leaf‐Fruit Position , 1969 .

[9]  D. Jackson.  Gibberellin and Growth in Stone Fruits: Induction of Parthenocarpy in Plum , 1968 .

[10]  J. Crane,et al.  Gibberellin induced parthenocarpy in Prunus. , 1960 .

[11]  C. A. Swanson,et al.  Translocation of Sugars in the Concord Grape. , 1958, Plant physiology.