Name: Yasmim Smarsaro Bonfá
Type: MSc dissertation
Publication date: 21/02/2019
Advisor:
Name |
Role |
|---|---|
| Elias Terra Werner | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Andreia Barcelos Passos Lima Gontijo | External Examiner * |
| Elias Terra Werner | Advisor * |
| Geraldo Rogério Faustini Cuzzuol | Internal Examiner * |
| Milene Miranda Praça Fontes | External Alternate * |
| Viviana Borges Corte | Internal Alternate * |
Summary: ABSTRACT
Cedrela fissilis Vell. (Meliaceae) is a forest specie with a widespread distribution in
Brazil. Due to its high commercial and economic value, it is target for extractivism
and indiscriminate exploitation, justifying its inclusion on the list of threatened
species. The random production of fruits that may leads to seeds with insufficient
quality plus the difficulties to their extraction cause a lack of raw material for
reforestration strategies. This problem makes in vitro propagation an efficient tool to
exploit the available seeds. Due to the extinction of several species, the
conservation necessity makes the research on use of tissue culture techniques
extremely important. Thereby, the present study aimed at describing a protocol for
an in vitro propagation using micropropagation technique of C. fissilis. For in vitro
germination, the media MS and B5 at total and fractional concentrations were
previously tested and the half-strength MS was used because presented better
results of germination rate (82) and germination speed index (1.218). For
micropropagation, the explants were cultured for buds induction on MS
supplemented with the isolated cytokinin, KIN or BAP (0 - 4μM). For root induction,
it was used MS supplemented with the isolated auxin, AIB or ANA (0 - 3 μM). The
buds induction was significantly affected in the number (3.84) and length (2.2) by
the explant origin and the concentration of cytokinin used in the process. The
highest number of buds were achieved in MS medium without cytokinin
supplementation. Rooting was achieved in all treatments, with root number per
explant being higher (2.55) for those supplemented with 3 μM indole-3-butyric acid.
Regenerated plants were acclimatized on commercial sterile substrate with ex vitro
survival rate higher than 10% after 30 days. Optimised protocols of
micropropagation offer the possibility of biotechnological techniques used for
studies of genetic engineering and vegetative propagation, as well as the
improvement of conservation strategies and intensive production of sampling. In the
case of C. fissilis, the protocol developed through this study, recommends the
induction of shoots by the cotyledon segment, without the use of cytokinin, as well
as the application of IBA in concentration at 3 μM in the rooting stage, which
potentiated the formation of adventitious roots in most explants tested. In short, the
protocol proposed here favors the micropropagation technique with easily replicable
results.
Keywords: micropropagation; protocol; cedar-pink.
