HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Egli, D. B. Articles by Leggett, J. E. Search for Related Content PubMed Articles by Egli, D. B. Articles by Leggett, J. E. Agricola Articles by Egli, D. B. Articles by Leggett, J. E.

Effect of Leaf and Pod Removal on the Distribution of ¹⁴C Labeled Assimilate in Soybeans¹

The effect of varying source-sink ratios on the distribution of ¹⁴C labeled assimilate in soybeans (Glycine max (L.) Merr.) was investigated in a greenhouse experiment. Varying source-sink ratios were created by pod (approximately 50%) or leaf removal (two side leaflets from each trifolioliate) at the end of flowering. A single leaf was exposed to ¹⁴CO₂ 17 days after application of the treatments. Pod removal reduced seed yield/plant and increased seed size, whereas leaf removal reduced yield, the number of seed/plant, and seed size. Seven hours after labeling a greater percentage of ¹⁴C remained in the leaf in the pod removal treatment (72%) than in either the leaf removal (55%) or the control (59%), and specific leaf weight was higher in the pod removal treatment.

The distribution of ¹⁴C 24 hours after labeling was not greatly affected by the treatments. The pod removal treatment had a greater percentage of ¹⁴C in the labeled leaf, in the stem both above and below the node of the labeled leaf, and less in the seed. Removal of the leaves did not affect the percentage of ¹⁴C in the labeled leaf after 24 hours or the distribution of the ¹⁴C in the plant, probably because the source-sink ratio was similar to that of the control. The primary effect of altering the source-sink ratio was on the movement of ¹⁴C labeled assimilate out of the leaf.

Key Words: Source-sink relationships • Glycine max (L.) Merrill. Defoliation • Yield components

² Associate professor, former postdoctoral fellow (now assistant professor, Newberry College, Newberry, SC 29108), and professor, Dep, of Agronomy, Univ, of Kentucky, Lexington, KY 40506.

Received for publication February 18, 1976.