Relationship between physiological, biochemical and leaf color characteristics in the initial growth of Eucalyptus sp. clones

Abstract

The work aimed to quantify physiological and biochemical variables, with potential for operational application in eucalypt clone seedling nurseries, during the expedition phase and to study their relationships with biometric variables evaluated during the initial growth in the field. Seedlings produced by apical mini-cuttings of two hybrid commercial clones of Eucalyptus grandis x Eucalyptus urophylla were used, cultivated in 53 cm³ tubes with organic substrate. The study consisted of evaluations in nursery, laboratory and in the field at 0, 30, 60, 90 and 120 days after planting. The data were submitted to analysis of variance and, when significant, were submitted to the Tukey test at 5% probability. The variables related to the seedling rusticity pattern, used subjectively by nurserymen, were quantified and validated in the nursery and in the field. The differences between clones were observed for the evaluated variables. The carbohydrate content and the leaf fluorescence index did not vary significantly between the classes of chlorophyll index. Leaf nitrogen content, proteins and water potential were directly proportional to the chlorophyll index. It was concluded that the canopy color of the seedlings may be related to rusticity and that the greenish tonality is more indicated because it has greater rusticity.

Keywords:
Hardening; Seedlings quality; Clonal forests