Fruit Growth and Ripening

Abstract

Botanically defined, the fruit is a mature ovary of the flower with or without any extracarpellary accessory parts. The wall of the ovary in the fruit is known as the pericarp, which becomes differentiated into three distinct layers: the outer exocarp, the middle mesocarp, and the inner endocarp. Double fertilization is the trigger that evokes endosperm development and embryogenesis, transforming the ovule into a seed. As these changes take place in the ovule, the ovary increases in size and undergoes a variety of morphological, anatomical, and biochemical changes leading to the formation of a fruit with enclosed seeds. Fruits such as banana (Musasp.) and pineapple (Ananas comosus) may develop in the absence of fertilization of the egg, and such fruits will not harbor any seeds at all or will have only aborted seeds, whereas plants such as tomato have genetic lines that produce only seedless fruits. Par-thenocarpy is the term used to describe the formation of fruits lacking seeds. It is now well known that the application of hormones such as auxins and gibberellins promotes parthenocarpic fruit development in apples (Malus domestica), grapes (Vitis vinifera), and tomatoes, among others. As a subject for analysis, fruit development has the same advantages as other systems of comparable sophistication from the vegetative and reproductive phases in the life of plants, because the fruit goes through periods of slow growth, accelerated growth, declining growth, and senescence.