Growth By Cell Division And Cell Expansion

Fruit tissue basically grows in two ways: by producing new cells (cell division) and by having those cells expand in size (cell expansion) (Coombe, 1976). In most fruit, cell division occurs in the first several weeks after flowering and represents the first 20 to 35 percent of a fruit's growing season. Cell division occurs in many cells in the fruit simultaneously, and as the number of cells increases, there are more cells to divide. For example, two cells divide to make four cells that can divide to make eight cells, and so on. Consequently, the number of cells and the fruit weight increase at a faster and faster rate in the early season. This is called the "exponential phase" of growth.

Before cell division is completed, a transition to growth by cell expansion begins in the cells that have completed cell division. When cell division is completed, all growth is then by cell expansion, which accounts for the majority of fruit growth. Final fruit size is dependent on cell numbers and cell size as well as production of intercellular air spaces.

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