masterThesis
Propagação vegetativa de Mimosa caesalpiniifolia Benth. por miniestaquia e análise morfoanatômica do enraizamento adventício
Fecha
2020-12-22Registro en:
FREIRE, Álvaro da Costa. Propagação vegetativa de Mimosa caesalpiniifolia Benth. por miniestaquia e análise morfoanatômica do enraizamento adventício. 2020. 110f. Dissertação (Mestrado em Ciências Florestais) - Escola Agrícola de Jundiaí, Universidade Federal do Rio Grande do Norte, Natal, 2020.
Autor
Freire, Álvaro da Costa
Resumen
Mimosa caesalpiniifolia is a forest species with great potential with a view to sustainable
logging in the Northeast region of Brazil, being considered a competitive source of renewable
energy due to its rapid growth. However, the production of seedlings with quality and quantity
still represents an obstacle in the silvicultural development of the species. Thus, vegetative
propagation can allow the cultivation of seedlings with high physiological and sanitary quality
in reduced space and time, optimizing large-scale production. The objective of this study was
to define a vegetative propagation methodology for the species M. caesalpiniifolia by ministither, aiming at the commercial production of seedlings. Specifically, the objective was to
evaluate the influence of indolebutyric acid and leaf reduction in adventitious rooting in shoots
from individuals with and without acúleo, as well as to study the dynamics and morphoanatomy
of adventitious rooting in this species. For this, two mini-garden systems were installed, the
canaletão system and in polyethylene vessels. The minigarden in canaletão was produced
from the collection and planting of seeds, which after installed provided shoots for construction
of the mini garden in polyethylene pots, this was established from selected phenotypes of M.
caesalpiniifolia based on the presence factor and absence of acúleo. In the canaletão system,
minicuttings were made using apic and intermediate shoots with 10 cm in length, keeping two
pairs of leaves and without reduction of leaf area, while in the vessel system, a picky
minicuttings were used with 10 cm in length, two pairs of leaves and without reduction of leaf
area, except for the experiment that evaluated leaf reduction, where the influence of three
reductions of leaf area for this species was tested. For the analysis of the concentration of
indolebutyric acid in both types of systems (canaletão and vessels) 4 concentrations (0, 2000,
4000 and 8000 mg L-1) were used. Stake in all experiments occurred in 55 cm³ tubes containing
organic bioplant substrate®. For the canaletão system, the evaluations took place at 30 days,
while in the vessel system the evaluations were performed at 30, 37 and 60 days after staking,
ascertaining the percentage of rooting, percentage of roots observed at the lower end of the
tubes, shoot length, diameter of the stake of the minicuttings, number of shoots, amount of
roots at the base of the minicuttings and fresh and dry biomass of the aerial part and root
system. In the influence of leaf reduction on the rooting of minicuttings, the complete reduction
of leaves (100%), reduction of 50 % and the use of leaves without reduction of the area (0 %)
were evaluated. In the dynamics of adventitious rooting, evaluations were performed every ten
days, observing the percentage of minicuttings with some degree of modification, oxidation of the base, presence of calluses and percentage of rooted minicuttings, as well as the average
length of the roots and the largest root. For morphoanatomical analysis, histological slides of
the region of origin of the roots were produced in the minicuttings and observed under optical
microscope. In the minicuttings of individuals with and without acúleo, the best results
regarding rooting without iba application are observed when using atypical and intermediate
shoots, respectively. The minisceps propagated via seminifera and managed in a sand
canalsystem and the mini strains propagated via minicutting and managed in pots produce
similar results regarding adventitious rooting. The shoots from both miniceps via seeds and
miniceps obtained via minicutting behave equally as to adventitious rooting. For adventitious
rooting in the minicuttings of phenotype with acúleo there is no need to use IBA, however, for
phenotype without acúleo, iba concentrations between 4000 mg L-1 (intermediate) and 8000
mg L-1 (apic) are recommended. The 50% reduction of leaf area is indicated for vegetative
propagation via minicutting of Mimosa caesalpiniifolia in individuals with and without acúleo.
Moreover, the rooting speed is equal for individuals with and without acumen and the
characterization of morphoanatomy in minicuttings indicates that there are no anatomical
barriers in the rooting of minicuttings, with roots arising from the exchange rate and callous
regions.