Anatomia da tuberosidade (Lignotuber) na região do coleto em Eucalyptus spp

Resumen

Anatomic studies were made on the tuberosities occurring in two periods of growth on Eucalyptus spp. In the first period, on two-month old plants it was observed that the tuberosities were more frequent on healthier and bigger plants. On the other hand, on two-year old plants, the opposite was observed, tuberosities were frequent on less developed plants.

On six month-old plants, the origin of the tuberosity was traced to the pith region and this is an intensive phenomenon causing lysis, regression, and wood tissue re-structuration, these bringing about pressure on the entire back tissue giving rise to tuberosity. In the second period of growth, only the tuberosity anatomy was studied, no attention being paid to its origin. The tuberosith in the second period is constituted of a completely abnormal structure and does not give rise to any bud, at least on the equatorial region. Therefore the lignotuber of Eucalyptus differ from similar structure found in savannah (cerrado) plants, which have definite structure and function.