Development, maturation and in vitro germination of seeds, and somatic embryogenesis of Eutepe edulis Martius
Name: TAMYRIS DE MELLO
Publication date: 28/02/2022
Advisor:
Name |
Role |
|---|---|
| RODRIGO SOBREIRA ALEXANDRE | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| EDILSON ROMAIS SCHMILDT | External Examiner * |
| RODRIGO SOBREIRA ALEXANDRE | Advisor * |
Summary: The species Euterpe edulis Martius, is a palm belonging to the Arecaceae family, popularly known as juçara, it is widely distributed in the Atlantic Forest. In recent decades this palm tree has been exploited for its palm heart, and the fact that it grows and propagates solely by seeds, the species is threatened with extinction. Its seeds are recalcitrant and its germination is slow and uneven, making it necessary to study the maturation process and another propagation technique. Therefore, the objective was to analyze seed maturation, twinning and seedling formation, in line with the development of somatic embryogenesis protocols. For this, seeds were collected during the maturation of different matrices, analyzing morphological, physiological, biochemical and physicochemical characteristics at each stage. For somatic embryogenesis, immature zygotic embryos and seedling stem segments were used as explants in a culture medium supplemented with different growth regulators at each stage, such as dichlorophenoxyacetic acid (2,4-D), 4-amino-3,5,6-trichloropicolinic acid (picloram), 3,5,6-trichloro-2- pyridinyloxyacetic acid (triclopyr), 3,6-dichloro-pyridine-2-carboxylic acid (clopyralyd), abscisic acid (ABA), 1 -naphthaleneacetic acid (ANA), 2- isopentenyladenine (2-iP), in different concentrations. At the end of each stage of somatic embryogenesis, quantitative and qualitative characteristics were analyzed. The time required for the maturation of E. edulis seeds depends on the region and the environmental conditions of each year. The seeds have sufficient reserves and physical-chemical structure that allow their maximum in vitro germination, vigor and formation of normal seedlings still at an immature stage. Embryogenic induction was efficient with the use of picloram (150 µM) or triclopyr (100 µM) in zygotic embryos, and the use of longitudinally sectioned segments and stems, with the wound positioned upwards in the culture medium, of sixmonth-old seedlings, and picloram (200 µM). The maturation of somatic embryos xi was effective with the use of ABA (5 µM) for both types of explants. Therefore, it was possible to conclude with the study of seed maturation the best stage for use in in vitro germination and obtaining normal seedlings, with a gain of up to 126 days compared to the use of the last stage of maturation. And the technique of somatic embryogenesis is promising and efficient in the propagation of E. edulis.
Keywords: seeds, germination, vigor, plant tissue culture, embryogenic
inducers, somatic embryos
