Data for Morphological and anatomical changes in leafless Vanilla spp. root system

Abstract

These data were collected in 2015 and include ecological information on leafless vanilla plants, as well as anatomical data on their roots, collected at various study sites during the course of this research project. A 50 × 20 m plot was established in a homogeneous zone of vegetation (Braun-Blanquet, 1932), where Vanilla spp. vines were present. The number of plots varied from two to three, depending on the size of the vegetation patches. Each plot was divided into 10 quadrats (10 × 10 m). The number of Vanilla spp. (vines and branches) per plot was recorded. The total length of the vanilla plants was measured. The number of attachment roots (AR) and aerial roots (ER) were counted per individual, and the shape of the AR (flattened or filiform) was noted. Morphological characteristics of the phorophytes were documented, including height, bark texture (smooth or rough), density, and diameter at breast height (DBH), which was measured 1.30 meters above the ground level. The rugosity assessment of the bark was performed by eye and touch. We compared the root anatomical structures of Vanilla spp. in northern and southern regions with high and low rainfall, respectively. The samples consisted of root segments of approximately 5 cm in length. Five samples were collected at different heights from the ground in aerial roots. These were the upper aerial root (UER) at 10 cm from the node, middle aerial root (MER) at mid-height, lower aerial root (LER) at 10 cm above the ground, main underground root (UMR), and secondary underground root (USR). The whole organ was collected for AR. Fifteen individuals were sampled at each locality. Root segments were preserved in 70° ethanol. For anatomical observation, freehand transverse sections were made with a microtome equipped with a razor blade yielding 20 µm thick sections, and then stained with carmine green (Mirande, 1920). Five anatomical sections were prepared for each of the 15 individuals sampled per site, resulting in 75 anatomical sections per site and 600 anatomical sections for the eight sites studied. Anatomical comparisons of the root sections from different locations were conducted using 30 anatomical sections of the MER per site. The sections were observed under an Olympus BX 43 light field microscope. The images were captured using a Canon EOS 5D Mark I camera. Morphometric evaluation of the organs was performed using ImageJ (Schneider et al., 2012), an image processing and analysis software package. The following anatomical characteristics of the roots were recorded: organ, stele, pith, metaxylem, and phloem diameter. The thickness of the epidermis, thickness of the cortex, number and diameter of the aerenchyma, and the number of vascular bundles were also recorded.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV