The similarities and differences in microstructure of phloem and xylem of Betula nana and Betula pubescens species

Arctic Biomonitoring

Bolotova, K.S.^1 ; Chukhchin, D.G.^1 ; Vydrina, I.^1 ; Novozhilov, E.^1

Biology, Ecology and Biotechnology Department, Northern (Arctic) Federal University, Arkhangelsk, Russia^1

关键词: Anatomical elements;    Betula pubescens;    Extreme temperatures;    Freeze drying;    Microstructural changes;    Sample preparation;    Secondary xylem;    Woody plants;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/263/1/012007/pdf
DOI  :  10.1088/1755-1315/263/1/012007

来源: IOP

【 摘 要 】

The formation of woody plants of the Arctic zone occurs with a certain direction of morphological and microstructural changes. An advanced approach to sample preparation associated with preliminary cryomechanical destruction and freeze-drying was used for microscopy of Betula nana and Betula pubescens sections. The sample images were obtained using an SEM Sigma VP Zeiss. Significant differences were found in two positions: the width of the secondary xylem fibers and the thickness of their cell walls. There is an anisotropy of the secondary phloem ray cells stretching: Betula nana cells are elongated vertically, and Betula pubescens - horizontally, and the ratio of cell height to width differ by more than 2 times. Thus, all morphological differences of the microstructure are concentrated only in the secondary xylem. Extreme temperatures of the Arctic territories are the cause of abnormal structural changes in the structure and affect the direction of morphogenesis of anatomical elements, which is especially evident in the development of xylem fibers.