Changes in the Nutritional Constituents in Cuttings during Propagation
II. Changes in Nitrogen and Carbohydrate Contents in Hardwood Cuttings of Grapevines
1972 Volume 41 Issue 2 Pages 127-132
Details
1972 Volume 41 Issue 2 Pages 127-132
1. Changes in nitrogen and carbohydrate contents in hardwood cuttings of grapevines (cv. Delaware) were investigated during propagation.
2. Dry weight of a whole cutting continued to decrease gradually through 60 days after planting and thereafter began to increase due to the growth of new shoots. The increase of dry weight in upper and lower half stems indicated that the newly photosynthesized matters in new shoots began to be translocated into the originalstems.
3. The soluble-nitrogen content (% dry weight) gradually decreased in both upper and lower half stems throughout the propagation period. While, the insoluble-nitrogen content decreased markedly only in upper half stems as the new shoots grew. The trend of total-nitrogen content was very similar to that of insoluble nitrogen content.
4. Distribution ratios of soluble-, insoluble-, and total-nitrogen in upper and lower half stems lowered rapidly as the new shoots and new roots developed. Eighty days after planting, the distribution ratio of total-nitrogen in new shoots, upper hlaf stems, lower half stems and new roots became 32%, 32%, 33%, and 3%, respectively. These values showed that a considerable amount of nitrogen moved from the lower parts to the upper parts of the cuttings.
5. Little differences were found in the contents (% dry weight) of starch, sugars and total carbohydrate between upper and lower half stems. The starch content generally decreased in both parts throughout the propagation period, while the total sugar content showed a marked decrease through 40 days after planting, followed by a temporary increase.
6. The decrease in the total carbohydrate content, which was more markedly in lower half stems than in upper half stems, was due to that of the sugar content. Between 40 and 80 days after planting, the contents of total carbohydrate and starch in upper half stems remained unchanged or increased slightly.
