Histological changes of the peanut (Arachis hypogaea) gynophore and fruit surface during development, and their potential significance for nutrient uptake

Abstract

Histological changes in gynophores and fruits of Arachis hypogaea L.cv. White Spanish were examined, utilizing scanning electron microscopy as well as light microscopy. The epidermis of the above ground parts of gynophores is characterized by the presence of stomata, lenticels and multicellular trichomes. Below ground portions of the same plant organ exhibit unicellular root-hair-like structures. These protuberances of the epidermal cells can reach a very high density and length (up to 0.75mm) . Identical structures can be found on the developing pod and are most prominent at the reproductive stages R5-R6. In later developmental stages the hairs degenerate and the presence of large lenticels becomes the obvious external feature of the pod. It is suggested that the substantial increase in surface area due to the hairs may well be an anatomical adaptation for nutrient and water uptake. © 1989 Annals of Botany Company.