Ray Traits of Juvenile Wood and Mature Wood: Pinus massonia and Cunninghamia lanceolata

Qiulu Meng,Jie Wang,Yafang Yin,Tuo He,Xiaomei Jiang,Feng Fu,Yonggang Zhang,Juan Guo,Ning Li

doi:10.3390/f12091277

Qiulu Meng, Jie Wang + Show 7 more

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https://doi.org/10.3390/f12091277

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Abstract

Ray traits affect secondary xylem development and wood properties. Pinus massonia and Cunninghamia lanceolata, commercially important timber species, were chosen to study the differences in wood ray traits of juvenile versus mature wood. Seven ray traits, i.e., percentage of rays, ray spacing, ray number, uniseriate ray height, fusiform ray height, ray parenchyma cell length and ray tracheid length, as well as eight wood axial tissue traits, were investigated quantitatively. Intraspecific variations in ray traits and axial tissue traits between juvenile wood and mature wood were displayed in violin plots. The results showed that anatomical differences between juvenile wood and mature wood were significant for both ray traits and axial tissue traits. Juvenile wood generally possessed the larger percentage of rays, higher ray spacing and ray number, smaller ray height and shorter ray cells than mature wood. A positive correlation was present between the ray parenchyma cell length and ray tracheid length. Negative correlations of the ray number and ray spacing with uniseriate ray height were found. Additionally, the axial tracheid cell wall thickness all had Pearson’s correlations with ray spacing, ray number and ray parenchyma cell length.

Highlights

Accepted: 14 September 2021Wood is a heterogeneous assemblage of cell walls deposited by the cell cytoplasm during differentiation [1]
Because the cambial age has an important effect on the structure of cambial cells and their derivatives [2], xylem is artificially defined by juvenile wood and mature wood, which are produced during the early years of cambial growth and the mature cambium, respectively
Pinus massonia (Masson pine) and Cunninghamia lanceolata (Chinese fir) are very important coniferous commercial timbers, whose domestic timber stock exceeds 943 million m3 and their proportion is above 27% [3]

Summary

Introduction

Accepted: 14 September 2021Wood is a heterogeneous assemblage of cell walls deposited by the cell cytoplasm during differentiation [1]. The diversity and extent of the cambium determine the wood structure. Because the cambial age has an important effect on the structure of cambial cells and their derivatives [2], xylem is artificially defined by juvenile wood and mature wood, which are produced during the early years of cambial growth and the mature cambium, respectively. In China, domestic commercial timber is mainly from the plantation forest. The average diameter at the breast height of domestic plantation timber is only about 12 cm, and the proportion of juvenile wood reaches to 40.72% [3]. Pinus massonia (Masson pine) and Cunninghamia lanceolata (Chinese fir) are very important coniferous commercial timbers, whose domestic timber stock exceeds 943 million m3 and their proportion is above 27% [3]. Deeply illustrating differences in the wood anatomical properties between juvenile wood and mature wood for these two species is urgently needed

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