Radial variations of anatomical characteristics and specific gravity in Eucalyptus camaldulensis clones

Five superior clones of Eucalyptus camaldulensis from in vitro propagation or tissue culture at the Sra Keaw plantation site in the eastern part of Thailand were selected for examining radial variations of anatomical characteristics and specific gravity. The age of the clones was 5 years at harvest. A 9-year-old tree grown from seed in the same site was also investigated. Results were as follows: 1) Mean specific gravity showed significantly different values among the 5 clones and the seedling. 2) Vessel density rapidly decreased in the first 2-4 cm from the pith in the clones and in 5 cm from the pith in the seedling. 3) Fiber lengths of the clones slowly increased from the pith outwards, while that of the seedling rapidly increased. 4) Each clone and the seedling had a different specific gravity and anatomical characteristics. 5) Clones had a narrower juvenile wood zone than the seedling due to the older cambial age of the clones.