https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35439 Eucalyptus bosistoana F. Muell. is valued for its naturally durable heartwood. As part of an E. bosistoana breeding programme, we have tested the hypothesis that there is a prolonged transition from sapwood to heartwood in young trees, resulting in a wide transition zone. This needs to be considered when assessing trees for heartwood quantity and quality. Heartwood formation was investigated in radial profiles in cores from bark to bark of 6-year-old trees with conventional and confocal microscopy, and with a range of different staining techniques that visualised the physiological changes taking place in the parenchyma cells. Using immunolabelling with antibodies against histone proteins and α-tubulin, histochemical staining using potassium iodide (I3-KI) and fluorescence emission spectral scanning, we demonstrated that in heartwood nuclei, microtubules, reserve materials (starch) and vacuoles were absent. The observations revealed that 6-year-old E. bosistoana trees contained heartwood. The loss of water conductivity by tyloses formation and the death of the parenchyma cells occurred in close proximity resulting in a transition zone of ~1 cm.]]> Thu 08 Aug 2019 09:22:16 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35265 Mon 08 Jul 2019 09:59:19 AEST ]]>