Morphological Characteristics and Allometric Relationships of Shoot in Two Undergrowth Plants: Polygonatum odoratum and Polygonatum multiflorum

Mirela Tulik,Joanna Jura-Morawiec,Natalia Szeliga,Ingeborga Jarzyna,Jerzy Karczewski

doi:10.3390/f9120783

Abstract

The main purpose of this investigation was to describe the spatial arrangement of shoot tissues, as seen in transverse section, and allometric relationships in two contrasting species of Polygonatum i.e., Polygonatum odoratum which commonly grows in mixed pine-oak forest with shoots rectangular in shape, and Polygonatum multiflorum found in oak-hornbeam forest with cylindrical shoots. The mass and length of the aerial shoots of each individual plant were measured. The shoot regions of each plant were then categorized as basal (b), central (c) or apical (a). Transverse sections of these shoot regions were subsequently cut, and the following parameters were measured: (1) Diameter of shoots, (2) thickness of the outer and inner zones of parenchyma and (3) thickness of the sclerenchyma zone. Additional allometric relationships between the various measurements were computed and determined as Pearson’s correlation coefficients (r). Both species of Polygonatum differed significantly with respect to the length, diameter and thickness of the outer zone of parenchyma. Shoots of P. multiflorum were taller but narrower than those of P. odoratum, which had a significantly wider zone of outer parenchyma. Allometric relationships were stronger for P. multiflorum, and for both species, they were generally stronger in the basal part of the shoot. We conclude that in P. multiflorum, the strong correlation between the diameter and length of the shoot seems to be important to the growth in shaded environments.

Highlights

Spatial organization of the plant body is defined as plant architecture subject to genetic and environmental control [1]
We examined two species of Polygonatum, growing on the forest floor namely Polygonatum odoratum (Mill.) Druce and Polygonatum multiflorum (L.) All, both members of the monocotyledonous family Asparagaceae (APG III 2009)
Shoots of the two species used for our study (P. multiflorum and P. odoratum) were collected in the late spring of 2015 and 2017

Summary

Introduction

Spatial organization of the plant body is defined as plant architecture subject to genetic and environmental control [1]. It is widely believed that the purpose of the mechanical integrity of the shoot is to ensure the reproductive success and survival of the plant [2]. Such mechanical integrity, and the peripheral location (or peripheral concentration in the case of monocots) of vascular bundles and mechanical supporting tissues such as collenchyma and sclerenchyma enable the plant to resist and respond to physical forces such as wind and are exacerbated by the weight of the plant itself [3]. Crook et al [4] demonstrated that plants occupying different habitats are able to modify their structural investment so as to maintain a “constant factor of safety” against mechanical failure.

Methods

Results

Conclusion