Anatomical Responses of Tomato Stems to Variations in the Macronutrient Anion Supply

Abstract

1. An inbred strain of Bonny Best tomatoes was grown in sand culture. The effects of forty-four nutrient solutions varying in the relative proportions of macronutrient anions were studied in relation to the anatomy of plant stems. Measurements of stem diameter and the actual area of each of the component tissue systems were recorded. The data were reduced and analyzed by statistical methods. 2. Great differences in stem diameter and the actual area of each of the component tissue systems could be correlated with differences in nutrient supply. 3. Differences in the relative proportion of phloem, xylem, and pith in stem sections were correlated with differences in nutrient supply. No differences were found in the relative amount of cortex. 4. Cellular differences in pith parenchyma, xylem vessels and fibers, internal and external phloem, internal and external pericyclic fibers, and cortical cells are described and correlated with nutrient supply. 5. Differences in the anatomy of the tomato stems are significantly correlated with characteristics used as criteria of vegetative growth and fruitfulness.