Morphophisiolophical characteristics of hardened woody species under water restriction

Abstract

The application of methyl jasmonate and mechanical stimuli seem to modulate morphological characteristics that are to ensure survival under adverse environmental conditions. The study aimed to evaluate morphological characteristics of woody species rustified with methyl jasmonate and stem bending under water restriction. Seedlings of Inga sessilis and Nectandra grandiflora were hardened with pulverization of 50 μmol L^-1 of methyl jasmonato, 20 stem bending daily and the control treatment for eight weeks. Afterwards, they were transplanted in vessels containing sand and submitted to water restriction for a month, being evaluated biweekly parameters such as increments of height (IH), diameter (IDC), leaf area (AF), leaf dry mass (MSF), stem dry mass (MSC) and root dry mass (MSR), root regeneration potential (PRR), electrolytes at the root (PER). The design was completely randomized with seven replicates of three seedlings each. In N. grandiflora, stem bending showed lower root emission, and when submitted to water restriction reduced AF, MSF and IH, until the end of the evaluated period. For I. sessilis, at time 0 and at day 15, the stem bending expressed lower MSF in relation to jasmonate, however, both did not differ from the control. At 15th the smaller AF was observed in the seedlings treated with stem bending, as well as the lower PER tissue. At the 30th day, both hardening treatments showed lower AF and MSF, and the jasmonato showed lower MSC and MSR in relation to the control treatment. Thus, the mechanical method is not recommended for hardening of Nectandra grandiflora, and both methods, chemical – with methyl jasmonato – and the mechanic – through stem bending – did not present satisfactory results that justify its use to hardening of seedlings of Inga sessilis.