Abstract The conservation of plant genetic resources is fundamental for the development of agriculture. The development of efficient cryopreservation protocols has become an effective tool to preserve cells, tissues and organs of different plant species. We sought here to develop an efficient method of cryopreservation of Eucalyptus grandis employing the V cryo-plate technique. This experiment examined the exposure of shoot tips to three different cryoprotectants (PVS2, PVS3, and PVS4). The cryoprotectants PVS2 and PVS4 proved to be more efficient among the cryoprotectants tested, as 44.4% of the shoot tips immersed in those solutions survived, and 31.1% generated new shoots. Ethylene glycol was found to be a key compound for the successful cryopreservation of shoot tips, in light of its low toxicity as compared to other cryoprotective compounds. Thus, the methodology developed here represents an effective method for the conservation of E. grandis germplasm through cryopreservation and the use of the V cryo-plate technique.

Abstract The efficiency of maize transformation mediated by Agrobacterium tumefaciens is influenced by various factors. The aim of this study was to test the effect of different concentrations of N6 salts (50% - half strength, and 100% - full strength) in the infection and cocultivation media on genetic transformation efficiency of the L3 tropical elite maize line. Immature embryos were transformed via A. tumefaciens harboring the binary vector pTF102 containing the genes uidA and BAR under control of the CaMV35S promoter. The efficiency of the transgenic events produced was 3% for full strength and 1.1% for half strength N6 salts. Although under a lower concentration of salts, GUS expression was stronger; under this concentration, regeneration was less efficient. Thus, the results showed that the presence of 100% N6 salts in the infection and cocultivation media favored genetic transformation of the L3 maize inbred line mediated by A. tumefaciens.

O experimento foi realizado para determinar a dose adequada de água de coco como suplemento para cultivo in vitro de embriões zigóticos de 19 genótipos de oliveira. Os embriões isolados das sementes de oliveira foram imersos em meio de cultura contendo 0 (controle), 25, 50, e 100mL L-1 de água de coco fresca e estéril, em condição de ambiente controlado durante 45 dias. A porcentagem de germinação, comprimento da parte aérea, número de raízes, número de folhas e número de internódios foram medidos para todos os 19 genótipos de oliveira. A ANOVA dos parâmetros avaliados apresentou interação significativa entre genótipos e dose de água de coco para o comprimento da parte aérea, número de folhas e número de internódios, e a dose de 100mL L-1, de forma geral, produziu os melhores resultados, como indicado pelas médias dos parâmetros analisados. No entanto, como mostra a interação significativa observada entre genótipos e tratamentos, é importante determinar a dose adequada de água de coco para cada genótipo.

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.

O objetivo deste trabalho foi avaliar o efeito da luz na germinação e desenvolvimento in vitro de embriões de 11 genótipos de oliveira, cultivados em meio MS. Os frutos foram coletados e os embriões de suas sementes extraídos assepticamente. Utilizaram-se duas condições experimentais de incubação: presença de luz, fornecida em sala de crescimento, com 16 h de luz com irradiância média de 36 µmol m-2 s-1, e ausência de luz, simulada em câmara de germinação tipo B.O.D.; ambos os tratamentos em temperatura de 25 ºC. Inicialmente, caracterizaram-se morfologicamente os frutos e sementes dos genótipos de oliveira, com medição do comprimento e diâmetro. Avaliaram-se o índice de velocidade de germinação (IVG), percentagem de germinação, comprimento de parte aérea, número de folhas e entrenós das plântulas. Maior IVG e percentagem de germinação foram observados em condições de incubação, na presença de luz para o genótipo 'Cerignola 131'. Maior comprimento de parte aérea e maior número de folhas e de entrenós das plântulas foram observados no genótipo 'Salomé 488', independentemente da condição de incubação.

The 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±1ºC, irradiance of 36 µmol m-2 s-1 and a photoperiod of 16 hours, and the absence of light using BOD temperature of 25 ºC. The germination was evaluated (speed index and percentage ratio) at the 10th day of incubation. Additionally, at the 45th 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.

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 4-5ºC e 15% de umidade relativa (UR), dessecador em geladeira a 4-5ºC e 12% UR, saco plástico em laboratório a 27±1ºC e 55% UR, dessecador em laboratório a 27±1ºC 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 4-5ºC e 12% UR, aos 30 dias. Esta condição de armazenamento preserva os frutos de oliveira por mais tempo.

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 4-5ºC and 15% relative humidity (RH), dissector in refrigerator at 4-5ºC and 12% RH, plastic bag at laboratory room at 27±1ºC and 55% RH, dissector in laboratory room at 27±1ºC 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 4-5ºC and 12% RH at 30 days. This storage condition preserves olive fruits for longer time.