On the Correlation of Area and Life Span of Leaves with Thickening Growth of Sugar Beet Root

Abstract

1) The vascular connection between tops and roots was traced after dyeing and also observed by microscopic photographs. It seems that the inner rings are connected with the older leaves and the outer rings with the younger leaves. Since the arrangement of the vascular bundles is thought to be governed by the phylotaxis (5/13), each leaf corresponds to 5/13=0.385 of each ring, in other words, 13/5=2.6 leaves correspond to one vascular ring. 2) On the basis of the premise as mentioned above, area and life span of each leaf and the volume of corresponding root tissue layor originated from its vascular cambium at harvesting time were measured. Then the correlation coefficient of the followings was calculated: (1) leaf area of 2.6 leaves and each volume of the corresponding root tissue layer originated from its vascular cambium. (2) leaf area of 2.6 leaves × life span of them and volume of corresponding root tissue layer originated from its vascular cambium. The correlation coefficient of (1) was 0.923^*** and (2) 0.882^***. By these findings, the suppositional structure of sugar beet was ascertained and thikening growth of root was shown to be strongly governed by the area and life span of corresponding leaf, especially by the former.