The influence of aluminium on the structural organization of the roots of barley in culture in Vitro

Abstract

The structural organization of roots, induced in the callus cultures of barley genotypes differing in aluminum tolerance: cv Kupetz, cv 999-93 and its somaclonal form R 999-93 was studied. The goal of this research was to determine how the toxic effects of aluminum at low pH affects the structure of the root and any cells damage of different tissues meristematic zone. At pH 5.8–6.0 root callus from different genotypes had specific features, manifested in the structure root cap, the epidermis, the form of roots. In the presence of 40 mg/1 Al³⁺ ions and pH 3.7–3.8 in the roots, callus was obtained from the cv Kupetz, there is strong damage to the epidermis, root cap and some other tissues, which, although and resulted in the death of cells, however, were not lethal character. In roots, callus derived from varieties 999-93, under the influence Al³⁺ ions was observed irreversible changes that lead either to compaction cytoplasm and nuclei, especially in the central part of the root or to the plasmolysis and the destruction of cells, especially in the meristematic zone. On transverse sections was found damaged cells of the central part of the root, formation of the densified outer cell wall of epidermal cells. At the investigation of R 999-93 callus roots it was be shown that most of the cells of meristematic zone of root retained their viability at influence of Al3+ ions. So, the somaclon from cv 999-93, obtained earlier in callus culture by selection on Al-tolerance, differs from the original form at the level of mesostructure.