Chemical Changes Accompanying Growth and Development of Seed and Fruit of the Elberta Peach

Publisher Website
Google Scholar
Abstract
The moisture content, reducing substances calculated as glucose, sucrose, ether extract (fat), total nitrogen, and ash (minerals), are given for the fleshy pericarp, stony pericarp, integuments, nucellus and endosperm, and embryo at regular intervals during the growing season at such times as the parts analyzed were of sufficient size to permit adequate sampling. The analyses are correlated with morphological development of the plant parts analyzed. The general patterns for chem. composition of fruit and seed parts of the peach during development is similar to that for much plant material. Especially is this true when the data are correlated with morph. development. E.g., during the first part of stage I, when active growth is taking place in the fleshy and stony pericarp and nucellus and integuments, and at a time when some of this growth is by cell division, the percentage moisture is relatively high and such labile forms as reducing sugars are also fairly high in amount. During stage II, when little increase in size occurs in the fleshy portion of the pericarp, changes in composition are small. It is during this period, however, that thickening and hardening of the cell walls of the stony pericarp begin, so that there is steady decline in % moisture, reducing sugars, sucrose, ether extract, and ash in that portion. Further, active growth of the embryo begins during this stage, correlated with high moisture level and low content of such storage forms as ether extract and nitrogenous substances. During stage III, when increase in size of the fleshy pericarp is rapid, caused largely by cell expansion, the sucrose content increases markedly and the moisture content slightly; while the percentages of reducing substances, ether extract, nitrogenous substances, and ash decline. On the other hand, since the cell walls of the stony pericarp thicken and harden still further during this period, and since it is not an organ for the storage of such materials as were included in the analyses, the percentages of moisture, reducing substances, sucrose, ether extract, nitrogenous substances, and ash decline to the lowest level observed during development. At the same time, in the embryo, which at fruit ripening contains a high % of such storage forms as ether extract and nitrogenous substances, rapid accumulation of these materials continues while the moisture declines. The data show the importance of careful separation of tissues intended for analyses and the value of considering the morph. nature of developing plant parts in connection with such analyses.

This publication has 0 references indexed in Scilit: