Studies show that most species of palm trees present seed dormancy. This characteristic hinders the production of seedlings, due to the long period for germination and the unevenness of the seedlings. The specie Syagrus coronata, despite being widely used as food and economic resources, presents also seed dormancy, which hinders its propagation. Thus, this work aimed at evaluating the germination of S. coronata seeds using different methods of dormancy breaking and also, under different qualities of light and temperature. To do so, the seed endocarps were scarified by friction, puncture and complete removal of the endocarp, and the pre-soaking of seeds at different concentrations (50, 100, 200 and 400 mg L-1) of gibberellic acid (GA3) and indolebutyric acid (IBA). We also evaluated the effect of germination in seeds exposed to different conditions of light (white, red, far red, blue and dark) and to different temperatures (25, 30, 35 and 20-30 °C). The data show that the act of rubbing the endocarp optimizes the seed germination process. Solutions containing growth regulators in the pre-soaking of seeds have a negative impact on germination. And the absence of light and the constant temperature of 25 °C are the most suitable for germination. The results indicate that S. coronata seeds have physical dormancy, and, despite obtaining greater germination in the dark, they are neutral photoblastic.

The experiment was carried out to determine the appropriate dose of coconut water as supplement for in vitro cultivation of zygotic embryos from 19 olive genotypes. The isolated embryos of the olive seeds were immersed on culture medium containing 0 (control), 25, 50, and 100mL L-1 of fresh and sterile coconut water and kept for 45 days under controlled environment. The percentage of germination, shoot length, number of roots, number of leaves and number of internodes were measured for all 19 olive genotypes. The ANOVA of the parameters evaluated showed significant genotypes x doses of coconut water interaction for shoot length, number of leaves and number of internodes and the dose of 100mL L-1 produced the best results overall as indicated by the means of measured parameters. However, the study showed the importance of determining the appropriate dose of coconut water for each genotype under consideration as shown by significant genotype x dose of coconut water interaction effect.

Effect of light on germination in vitro of zygotic embryos of olive genotypesThe purpose of this study was to evaluate the influence of light in the in vitro development of embryos from eleven olive genotypes on MS medium. The fruits were collected, and their embryos were extracted aseptically. Two experimental conditions of incubation were used: the presence of light, in a growth room at 251C, irradiance of 36 mol m -2 s -1 and a photoperiod of 16 hours, and the absence of light using BOD temperature of 25 °C. The germination was evaluated (speed index and percentage ratio) at the 10 th day of incubation. Additionally, at the 45 th day, the shoot length, the number of leaves and the internodes of seedlings were recorded. The best speed index and germination percentage occurred in conditions of incubation in the presence of light. The genotype 'Salome', access 488, presented the greatest shoot length, and the highest number of leaves and internodes, independent of the incubation condition.

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Resumo -O objetivo deste trabalho foi avaliar o efeito de diferentes condições de armazenamento na preservação da viabilidade e da germinação de embriões zigóticos de oliveira. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 4x2. Frutos da cultivar Santa Catalina foram submetidos a diferentes condições de armazenamento -saco plástico em geladeira a 4-5°C e 15% de umidade relativa (UR), dessecador em geladeira a 4-5°C e 12% UR, saco plástico em laboratório a 27±1°C e 55% UR, dessecador em laboratório a 27±1°C e 30% UR -e aos períodos de armazenamento de 30 e 120 dias. A germinação in vitro e a viabilidade foram avaliadas pelo teste de tetrazólio aos 30 e 120 dias de armazenamento. A maior taxa de germinação (91,66%) e de viabilidade (33,33%) foram observadas a 4-5°C e 12% UR, aos 30 dias. Esta condição de armazenamento preserva os frutos de oliveira por mais tempo.Termos para indexação: Olea europaea, fisiologia de sementes, germinação in vitro, teste de tetrazólio. Viability and germination of olive embryos subjected to different conditions of fruit storageAbstract -The objective of this work was to evaluate the effect of different storage conditions on the preservation of the viability and germination of olive zygotic embryos. A completely randomized block design was used, in a 4x2 factorial arrangement. Fruits of the cultivar Santa Catalina were subjected to different storage conditions -plastic bag in refrigerator at 4-5°C and 15% relative humidity (RH), dissector in refrigerator at 4-5°C and 12% RH, plastic bag at laboratory room at 27±1°C and 55% RH, dissector in laboratory room at 27±1°C and 30% RH -, and to storage periods of 30 and 120 days. In vitro germination and viability were evaluated by the tetrazolium test at 30 and 120 days of storage. The highest germination rate (91.66%) and viability (33.33%) were observed at 4-5°C and 12% RH at 30 days. This storage condition preserves olive fruits for longer time.

– The improvement of tropical maize inbred lines by genetic transformation techniques remains a difficult task since not all genotypes are capable of regenerating efficiently in vitro. The objective of this study was to evaluate three different callus induction media, based on N6 or MS salts containing either 2,4-D (0, 2.5, 5.0, 10.0, 15.0, 30.0 mg .L-1) or Dicamba (0; 0.25; 0.5; 1.0; 2.0; 4.0 mg.l-1) in the production of embryogenic callus from immature zygotic embryos of the tropical maize inbred line L3. Callus maturation was tested in MS medium containing 60 g.L-1 sucrose and supplemented with different combinations of BAP (0; 0.1; 0.5; 1.0 mg.L-1), NAA (0; 1.0 mg.L-1) and CuSO4 (0; 1.25 mg.L-1). The L3 inbred line presented higher capacity for Type II callus formation on N6 medium content 10 mg.L-1 2,4-D. For the maturation of callus, absence of plant growth regulators and addition of CuSO4 allowed higher percentage of regeneration. The protocol developed presented 85% production of Type II embryogenic callus and 45% plant regeneration.Keywords: 2,4-D, dicamba, embryogenic callus, Zea mays.EMBRIOGÊNESE SOMÁTICA E REGENERAÇÃO DE PLANTAS A PARTIR DE UMA LINHAGEM DE MILHO TROPICAL ELITERESUMO – O melhoramento de linhagens de milho tropical através de técnicas de transformação genética continua a ser uma tarefa difícil uma vez que nem todos os genótipos são capazes de regenerar eficientemente in vitro. O objetivo deste estudo foi avaliar três meios diferentes para a indução de calos embriogênicos, baseados em N6 ou MS sais contendo 2,4-D (0; 2,5; 5,0; 10,0; 15,0; 30,0 mg.L-1) ou Dicamba (0; 0,25 ; 0,5; 1,0; 2,0; 4,0 mg.l-1) na produção de calos embriogênicos a partir de embriões zigóticos imaturos da linhagem de milho tropical elite L3. A maturação dos calos foi testada em meio MS com 60 g.L-1 de sacarose suplementado com diferentes combinações de BAP (0; 0,1; 0,5; 1,0 mg.L-1), ANA (0; 1,0 mg.L-1) e CuSO4 (0; 1,25 mg L-1). A linhagem L3 apresentou alta capacidade para produção de calos do Tipo II em meio N6 contendo 10 mg.L-1 de 2,4-D. Para a maturação dos calos, ausência de reguladores de crescimento vegetal e adição de CuSO4 possibilitou maior porcentagem de regeneração. O protocolo desenvolvido apresenta produção de 85% de calos embriogênicos do Tipo II e 45% de regeneração de plantas.Palavras-chave: 2,4-D, dicamba, calos embriogênicos, Zea mays

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This study aimed to develop efficient protocols for the in vitro micropropagation of Byrsonima gardneriana. ). The use of concentrations from 2.0 to 4.0 µM 6-benzylaminopurine was efficient in the multiplication of B. gardneriana, given that, using concentrations above these, a decrease in this efficiency occurs. The use of auxin interfered negatively with the results. In vitro rooting occurs even in medium free of auxin. The activated charcoal was insufficient for rooting. The use of growth regulators 6-benzylaminopurine and indole butyric acid are efficient in micropropagation of B. gardneriana, however, further studies should be performed to optimize this protocol.