A Histological Study of Regeneration in the Epicotyl of Tomato

Abstract

Investigations on regeneration in plants may be divided into categories includintg those involving the application of growth substances and those which do not involve the application of growth substances. During recent years, a vast amount of research has been conducted to demonstrate the effects of various growth substances on plants. Of particular significance are the investigations of Kraus et al. (1936) who studied the responses of bean plants to indoleacetic acid and Borthwick et al. (1937) who carried out an investigation to determine the reaction of tomato plants to indoleacetic acid. The results of investigations in this category show a wide variety of patterns and have been adequately reviewed by Avery and Johnson (1947), Mitchell and Marth (1947), and Skoog (1947, 1951). Investigations on regeneration not involving the application of growth substances have been reviewed by Swingle (1940, 1951), Guillermond (1942) and White (1936, 1946). Of particular interest in this category are the works by Crooks (1933) whose study dealt with regeneration in flax seedIings and Bain (1940) who determined the origin of adventitious shoots in decapitated cranberry seedlings. It was noted by Wildman (1952) that when tomato seedlings were decapitated and treated with lanolin, a callus resulted on which buds and leaf primordia were frequently observed. The present investigation is a histological study of the changes which were involved following decapitation.