masterThesis
Caracterização biométrica de diásporos e sementes e propagação sexuada e vegetativa de Cordia oncocalyx (Allemão) Baill
Fecha
2020-12-22Registro en:
ARAÚJO, Jayane Karine Pereira de. Caracterização biométrica de diásporos e sementes e propagação sexuada e vegetativa de Cordia oncocalyx (Allemão) Baill. 2020. 143f. Dissertação (Mestrado em Ciências Florestais) - Escola Agrícola de Jundiaí, Universidade Federal do Rio Grande do Norte, Natal, 2020.
Autor
Araújo, Jayane Karine Pereira de
Resumen
Cordia oncocalyx (Allemão) Baill, popularly known as pau-branco is an endemic species of
the Caatinga and has multiple uses. Due to the lack of information to enable its perpetuation
and conservation, studies related to biometric evaluation, as well as the propagation are
important for the production of seedlings of the species. The objective of this work was: to
analyze the biometric characteristics of diaspores and seeds manually and by digital image
analysis, in order to compare the best evaluation method; and to analyze progagation
through in vitro germination, ex vitro emergence, and cuttings of C. oncocalyx, with a view to
optimizing the production of seedlings of the species. For the determination of biometric
parameters by manual and digital method, 300 diaspores and 300 seeds were used.
Subsequently, the ex vitro emergency was performed, testing the following treatments on the
diaspores: control (without scarification), scarification in the peduncular region with and
without hydration for 24 h, scarification in the region opposite the peduncle with and without
hydration for 24 h, scarification in the lateral portion with and without hydration for 24 h,
scarification with immersion in sulfuric acid for 90 min and for 180 min. In vitro germination
was also tested, using different compositions of the culture medium: 12 g.L-1
of sucrose and
1.80 g.L-1
of MS medium; 12 g.L-1
of sucrose and 0.90 g.L-1
of MS medium; 6 g.L-1
of sucrose
and 1.80 g.L-1
of MS medium; 6 g.L-1
of sucrose and 0.90 g.L-1
of MS medium. For the
evaluation of the effect of the time of collection and the use of indolbutyric acid (IBA) on the
rooting of cuttings of C. oncocalyx, the propagules were collected in Mossoró-RN, in April
and July 2019, and in February 2020 The AIB concentrations tested were 0; 2000; 4000 and
8000 mg.L-1
. With regard to the use of AIB and the pyroligneous extract in rooting C.
oncocalyx, the cuttings were immersed in AIB solution at concentrations of 0; 2000; 4000 and
8000 mg.L-1
and pyroligneous extract at 0; 10; 100; 500 and 1000 ml.L-1
. Regarding the
determination of the optimal rooting time, and the evaluation of the number and length of
roots by manual and digital method, every 10 days from the date of staking, evaluations were
made regarding oxidation, swelling, presence of calluses and rooting at the base of the piles.
Regarding the results obtained, it was demonstrated that digital image processing is a viable
and fast technique in obtaining biometric parameters for diaspores and seeds. Chemical and
mechanical treatments in the diaspores did not promote the emergency. The composition of
the culture medium influenced the percentage of in vitro germination, with the maximum
value (96% of germination) observed with 6 g.L-1 of sucrose and 0.90 g.L-1 of MS medium. Seminiferous propagation of C. oncocalyx can be successfully performed when the seeds
are germinated in vitro and digital image processing shows solidity and applicability with a
view to the evaluation of quantitative parameters of C. oncocalyx fruits and seeds. The
cutting performed in February (rainy season) using 2000 mg.L-1
of IBA promoted higher
percentages of survival, rooting and better quality of the seedling produced. The use of IBA
and EP, in shoots collected at the beginning of the dry season, are not indicated as inducers
of adventitious rooting in cuttings of C. oncocalyx. It was found that the cuttings collected in
the dry season need to remain in the propagation environment for about 76 days, to achieve
100% rooting. Digital image analysis is a fast and accurate tool in obtaining the length and
number of roots, as well as providing additional characters, such as the area and perimeter
of the roots of C. oncocalyx. Therefore, it is concluded that the present study contains
silvicultural information that can contribute to the production of seedlings and perpetuation of
C. oncocalyx.