Functional Principles of Morphological and Anatomical Structures in Pinecones

Abstract

In order to better understand the functions of plants, it is important to analyze the internal structure of plants with a complex structure, as well as to efficiently monitor the morphology of plants altered by their external environment. This anatomical study investigated structural characteristics of pinecones to provide detailed descriptions of morphological specifications of complex cone scales. We analyzed cross-sectional image data and internal movement patterns in the opening and closing motions of pinecones, which change according to the moisture content of its external environment. It is possible to propose a scientific system for the deformation of complex pinecone for the variable structures due to changes in relative humidity, as well as the application of technology. This study provided a functional principle for a multidisciplinary approach by exploring the morphological properties and anatomical structures of pinecones. Therefore, the results suggest a potential application for use in energy-efficient materials by incorporating hygroscopic principles into engineering technology and also providing basic data for biomimicry research.

The Kinematics of Scale Deflection in the Course of Multi-Step Seed Extraction from European Larch Cones (Larix decidua Mill.) Taking into Account Their Cellular Structure

“…It was calculated that at the end of the extraction process, the scale opening angle ranged from 140 • to 145 • at a moisture content of 5% to 10%. For larch, the maximum values of the scale opening angle were much higher than those obtained by Bae and Kim [29], who differentiated between the right (120.7 • ) and left (111.6 • ) bracts of Pinus cones. However, these figures cannot be directly compared due to differences in the angle measurement methodology.…”

“…The methodology for investigating the scale opening angle was described by Dawson et al [ 35 ], who studied Pinus radiata cones, and by Aniszewska [ 34 ], who studied Pinus sylvestris , Picea abies and Larix deciduas cones. It was also followed by Bae and Kim [ 29 ] in their investigation of the scale opening angle in pine cones ( Pinus ).…”

“…Cross-sections of scales with a moisture content of 20% were examined using a Nikon Alphaphot-2 YS2 biological microscope (Nikon, Tokyo, Japan) coupled to a Panasonic GP-KR222E camera (Panasonic, Kadoma, Japan). This measurement method was used for spruce cones by Aniszewska [34] and for pine cones by Bae and Kim [29]. Samples of scales with a moisture content of 5% were taken using an NT Cutter BA-170 blade (NT Incorporated, Tokyo, Japan) with a WSL-lab microtome (Swiss Federal Research Institute WSL, Zürich, Switzerland).…”

“…The structure and properties of cell layers may affect the mechanical movement of scales [ 29 ]. The humidity of air surrounding the cones has a significant impact on moisture absorption and transpiration of the water vapor contained in the scale cells, which, due to changes in the temperature of the drying air, expand and contract anisotropically in a direction perpendicular to scale tissue orientation [ 30 , 31 ].…”

“…In addition to a publication by Aniszewska [ 33 , 34 ], the available literature provides some other studies on the cone structure and the scale opening process [ 29 , 35 , 36 , 37 ], but these do not concern European larch cones.…”