In vitro germination and growth of babassu (orbygnia phalerata Mart.) embryos subjected to different drying temperatures

The aim of this study was to evaluate the physiological quality of babassu (Orbygnia phalerata Mart.) embryos in relation to drying rate. The fruits were kept in a dry chamber with forced air circulation at 57 ± 2°C and 37 ± 2°C for 0, 6 and 11 days. An interaction between the drying time and temperature on water loss was not observed. Fruits dried at 37 ± 2°C failed to achieve the same water content values as those dried at 57 ± 2°C. Embryos dehydrated at 37 ± 2°C remained viable even after 11 days of drying, while embryos dehydrated at 57 ± 2°C were dead after 6 days of drying. Germination percentages above 67% were obtained for all times at drying 37°C, even for seeds with 9% water content, which highlights a possible orthodox behavior. Under the experimental conditions of the present study, drying embryos at 57 ± 2°C decreased the percentage and speed of germination as well as the initial growth of seedlings.Keywords: Arecaceae, desiccation tolerance, orthodox seed

Overcome dormancy of seeds of Tucum (Astrocaryum huaimi Mart.)

The objective of this study was to evaluate the effect of immersion for varying periods in different concentrations of gibberellic acid and separate methods of scarification on the germination of seeds tucum. In the first trial, testing different soaking periods (24 and 48 hours), different forms of soaking (fast and slow) and different concentrations of gibberellic acid (0, 100 and 200 mg L-(1)) compared to the control (water) under completely randomized design in a factorial 2x2x3. The second experiment evaluated the different scarification treatments being: physical (seed coat removal in the hilar region with the aid of a scalpel), chemical (sulfuric acid 98 PA for 2:04 minutes) and thermal (hot water at approximately 98 degrees C and cold water at about 2 degrees C for 4 minutes). In the first trial were evaluated % of contaminated seeds (seeds infected by microorganisms) and hard seeds (who did not start the germination process, but not soiled), and in the second we assessed germination percentage (%) every two days for three months; germination Speed Index (GSI), time to occurrence of 50 % germination (T50) and Emergency Speed Index (ESI). The use of gibberellic acid was ineffective in promoting germination of Tucum (Astrocaryum Huaimi Mart.). Scarification treatments were effective in promoting germination and emergence of seedlings in the nursery and the most efficient physical removal scarification of the seed coat in the hilar region with the highest percentage of germination

Effects of drying temperature on viability of macaw palm (Acrocomia aculeata) zygotic embryos

Submitted by Luciana Ferreira ([email protected]) on 2018-04-12T14:36:10Z No. of bitstreams: 2 Artigo - Aurélio Rubio Neto - 2015.pdf: 755268 bytes, checksum: 3ebba181e8c41aebbbc7cc934c250568 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Approved for entry into archive by Luciana Ferreira ([email protected]) on 2018-04-13T11:55:45Z (GMT) No. of bitstreams: 2 Artigo - Aurélio Rubio Neto - 2015.pdf: 755268 bytes, checksum: 3ebba181e8c41aebbbc7cc934c250568 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Made available in DSpace on 2018-04-13T11:55:45Z (GMT). No. of bitstreams: 2 Artigo - Aurélio Rubio Neto - 2015.pdf: 755268 bytes, checksum: 3ebba181e8c41aebbbc7cc934c250568 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-01In response to a growing interest in improving seedling production of oilseed species (like macaw palm), a fruit drying protocol for facilitating seed extraction was proposed. This enabled the production of macaw palm seedlings, but the temperature most suitable for seed extraction without losing its physiological quality is unknown. The goal of this study was to evaluate the effects of different drying temperatures on the physiological quality of macaw palm zygotic embryos to improve previously published drying methods. Fruits were dried in a forced-air drying oven at 57 or 37°C at different time periods (zero, two, four, six and eight days). Following each drying period, the fruits were removed from the drying oven, and the water content of the fruits and seeds were measured in addition to embryo viability and in vitro germination. Seed water content could be estimated based on fruit water content at both drying temperatures, eliminating the need to remove the seeds from the fruit. Drying at 57°C decreased the drying time by 50% compared to drying at 37°C; however, it was detrimental to embryo viability and germination. Therefore, drying of fruit at 37°C is recommended. Embryos dried at this temperature were still able to germinate after 16-day drying period, which corresponded to a decrease of 24.8% in the initial fruit water content