QUANTITATIVE DETERMINATION OF SIEVE‐TUBE DIMENSIONS IN RICINUS, CUCUMIS AND MUSA

Abstract

The percentage cross‐sectional area of sieve tubes in the phloem of Ricinus communis L. var. Gibsonii, Cucumis myriocarpus Naud. and Musa sp. L. (cv. Williams) was determined from thin serial sections stained for callose fluorescence. A new maceration method was developed to measure the percentage cross‐sectional area as well as the dimensions of a large number of sieve‐tube members in Ricinus. Determinations of the proportion of sieve tubes in the phloem showed that this varied in different plants, and also in different parts of the same plant. Except in Cucumis, the petiole showed a much higher proportion when compared with stem and fruit stalk. The measurements of the diameter and length of sieve tube members in Ricinus revealed interesting distribution patterns. Copyright © 1984, Wiley Blackwell. All rights reserved