Influence of fertilizer treatment on apple fruit composition and physiology. 1. Influence on cell size and cell number.

Abstract

Cell size and cell number in Sturmer Pippin apple fruits from trees receiving different fertilizer treatments have been determined. N fruit contained larger cells than U, P, NP, or NPK fruit of the same weight (K = 2 lb sulphate of ammonia, P = 4 lb superphosphate, and K = 1 lb sulphate of potash per tree per year: U = no fertilizer). Fruit from the latter four treatments did not show any consistent differences in cell size. In fruit of the average size for each treatment, differences in cell number per fruit were present,, N fruit containing fewer and larger cells than fruit from all other treatments. Cell number of NPK fruit was greater than that of U fruit. Mean cell volumes for fruit from the various treatments were significantly correlated with the incidences of internal breakdown in storage in each of three years. IS fruit of varieties Cox's Orange Pippin and Dunn's Favourite contained larger cells than U or SPK fruit of the same size. Delicious SPK fruit contained smaller cells than U or IS fruit), the cell sizes of which did not differ.

Relationship between density and stiffness of apple flesh

“…This difference in morphology alone may account for the anomaly that the outer layers, although of lower density, have the same stiffness in several of the varieties of apple and indeed, in the 'master' curves, show a greater modulus at any particular density or area of cell contact ( Figs 6 and 7). There is no evidence for a gradient in thickness of cell walls (Tetley 1931), although there is some evidence that cortical ('outer') cells are smaller than the pith ('inner') cells (Bain and Robertson 1951;Reeve 1953;Letham 1961). These two observations suggest that there is more cellulose per cell in the outer layers, which could make these cells stiffer.…”

Relationship of Instrumental and Sensory Texture Measurements of Fresh and Stored Apples to Cell Number and Size

“…Cell size has been determined to infl uence fresh fruit texture (Allan-Wojtas et al, 2003). Tissue breakdown during storage was found to be positively correlated to cell size (Letham, 1960). In contrast, Smith (1940) found that varieties with larger cells have better keeping qualities and lower respiratory rates than varieties with smaller cells.…”

Synthetic cytokinins extend the phase of division of parenchyma cells in developing pear (Pyrus communisL.) fruits

“…From our histological study, cytokinin application may affect the expression patterns of these genes. The smaller cells in CPPU-or TDZ-treated fruit could be beneficial to increase fruit resistance to pests (Sarig et al, 1998), and/or to improve storability (Reynolds et al, 1992;Letham, 1961) and taste (Ho, 1996).…”