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Este estudo objetivou avaliar a influência das citocininas durante o estágio de multiplicação in vitro e a combinação entre carvão ativado com o ácido indol-3-butírico (AIB) durante o enraizamento in vitro de Handroanthus impetiginosus. Para a multiplicação in vitro, os segmentos nodais dos brotos obtidos a partir do estabelecimento de plântulas in vitro foram inoculados em meio de cultura Woody Plant Medium (WPM), com e sem as seguintes concentrações de 6-benzilaminopurina (BAP), cinetina (KIN) e tidiazuron (TDZ): 0,5; 1,0; 2,0; 4,0 e 8,0 µmol L-1. Para o enraizamento in vitro, brotos foram inoculados em meio WPM contendo combinações entre AIB (1,0; 3,0; 6,0 e 9,0 μmol L-1) e carvão ativado (1,0; 2,0 e 3,0 g L‑1), bem como suas ausências no meio de cultura. O maior número de brotos e gemas foi alcançado após usar 8,0 μmol L-1 de TDZ, enquanto que o melhor enraizamento ocorreu após a adição de 2,0 g L-1 de carvão ativado, independente da concentração de AIB. Nossos resultados mostram que usar TDZ em níveis adequados para o estágio de multiplicação in vitro seguido pelo uso de 2,0 g L-1 de carvão ativado para obter brotos bem enraizados é eficiente para a micropropagação de ipê-roxo de maneira rápida e com baixo custo, além de fornecer conhecimento sobre como manter esta espécie ameaçada de extinção em um ambiente in vitro podendo ajudar outros estudos de conservação.

The main objective of this study was to characterize the toxicity and genetic divergence of 18 Bacillus thuringiensis strains in the biological control of Spodoptera eridania . Bacterial suspensions were added to the S. eridania diet. Half of the selected B. thuringiensis strains caused high mortality seven days after infection. The genetic divergence of B. thuringiensis strains was assessed based on Enterobacterial Repetitive Intergenic Consensus (ERIC) and Repetitive Extragenic Palindromic (REP) sequences, and five phylogenetic groups were formed. Despite their genetic diversity B. thuringiensis strains did not show any correlation between the collection sites and toxicity to larvae. Some B. thuringiensis strains are highly toxic to S. eridania, thus highlighting the potential of their endotoxins as biopesticides. Made available in DSpace on 2020-01-24T18:15:54Z (GMT). No. of bitstreams: 1 Molecularcharacterization.pdf: 1710147 bytes, checksum: 97496a069d958bd447d0de28d1e7209b (MD5) Previous issue date: 2020

Background Coffee production relies on plantations with varieties from Coffea arabica and Coffea canephora species. The first, the most representative in terms of coffee consumption, is mostly propagated by seeds, which leads to management problems regarding the plantations maintenance, harvest and processing of grains. Therefore, an efficient clonal propagation process is required for this species cultivation, which is possible by reaching a scalable and cost-effective somatic embryogenesis protocol. A key process on somatic embryogenesis induction is the auxin homeostasis performed by Gretchen Hagen 3 (GH3) proteins through amino acid conjugation. In this study, the GH3 family members were identified on C. canephora genome, and by performing analysis related to gene and protein structure and transcriptomic profile on embryogenic tissues, we point a GH3 gene as a potential regulator of auxin homeostasis during early somatic embryogenesis in C. arabica plants. Results We have searched within the published C. canephora genome and found 17 GH3 family members. We checked the conserved domains for GH3 proteins and clustered the members in three main groups according to phylogenetic relationships. We identified amino acids sets in four GH3 proteins that are related to acidic amino acid conjugation to auxin, and using a transcription factor (TF) network approach followed by RT-qPCR we analyzed their possible transcriptional regulators and expression profiles in cells with contrasting embryogenic potential in C. arabica. The CaGH3.15 expression pattern is the most correlated with embryogenic potential and with CaBBM, a C. arabica ortholog of a major somatic embryogenesis regulator. Conclusion Therefore, one out of the GH3 members may be influencing on coffee somatic embryogenesis by auxin conjugation with acidic amino acids, which leads to the phytohormone degradation. It is an indicative that this gene can serve as a molecular marker for coffee cells with embryogenic potential and needs to be further studied on how much determinant it is for this process. This work, together with future studies, can support the improvement of coffee clonal propagation through in vitro derived somatic embryos.

Hancornia speciosa Gomes is a fruit species belonging to the Apocynaceae family and holds social, cultural and economic potential mostly due to its use in composition of many food industry products and the consumption its fruits in natura . Several aspects regarding their propagation need further studies, since the species is undergoing a continuous process of domestication. The objective was to obtain an in vitro protocol for indirect organogenesis and rooting with subsequent acclimatization of H. speciosa plants. To obtain indirect organogenesis, internodal segments were inoculated in WPM culture medium gelled with 7 g L -1 agar, added with 30 g L -1 sucrose, 0.4 g L -1 PVP, and supplied with different concentrations of 2,4-D (0.0; 2.46; 7.38; 12.30; and 17.22 µM), BAP (0.0; 4.92; 9.84; 14.76; and 19.68 µM), and TDZ (0.0; 4.92; 9.84; 14.76; and 19.68 µM). For the in vitro rooting, shootings with approximately 6.0 cm diameter length kept for 15 days in WPM medium with no plant growth regulator and, afterwards, subjected to treatments with different auxins (Control; 9.84 µM IBA; 9.84 µM NAA; and 9.84 µM IAA) as well as the combination among them, in order to verify their effects on percentage of rooting (%), number of roots, and average length of the largest root (cm). The formation of calluses was observed in all explants subjected to the concentrations of the regulators tested. The highest shooting regeneration occurred with 7.38 µM 2,4-D (73%). The highest percentage of shoot rooting (80%) and roots with the largest length (1.3 cm) were found in the culture medium with the combination of 4.92 µM NAA and 4.92 µM IBA. The in vitro regeneration of H. speciosa is feasible. The acclimatization of rooted shoots in Trospstrato® was accomplished with successful and 100% survival of plant material was observed during this stage.

Este trabalho teve por objetivo avaliar a influência do tipo de vedação e substrato na pré-aclimatização e os aspectos sintomatológicos na aclimatização de Ipê-roxo. Para pré-aclimatização, plantas de Ipê-roxo obtidas in vitro por meio de cultura de embriões zigóticos foram inoculadas assepticamente em tubos de ensaio contendo diferentes tipos de vedação (algodão, tampa plástica + parafilme e tampa plástica) e diferentes substratos (ágar, vermiculita e Plantmax®) suplementados com meio de cultivo WPM acrescidos de 1 gL-1 de carvão ativado, 10 mgL-1 de ácido cítrico e 30 gL-1 de sacarose. Para a aclimatização, plantas de Ipê-roxo obtidas in vitro foram transplantadas para tubetes de 56 cm³; contendo vermiculita e Plantmax®na proporção 2:1, previamente autoclavado a 121ºC e 1 atm, por 20 minutos. Após o transplantio, as plantas foram irrigadas com diferentes concentrações do meio MS (25%, 50%, 75%, 100% e 150%), sendo utilizada como controle água destilada. Após 30 dias, foram verificados efeitos do tipo de vedação e substrato na pré-aclimatização. O algodão pode ser recomendado quando se utiliza Plantmax®ou vermiculita como substrato. Na aclimatização, verificou-se que as plantas quando irrigadas com água destilada e concentrações < 50% apresentaram sintomas de deficiência nutricional. Foram observados sintomas semelhantes com a utilização de MS em concentração igual ou superior a 100%. A concentração 75% do meio MS foi a mais eficiente na manutenção do vigor nutricional de mudas de Ipê-roxo em processo de aclimatização. This work evaluated the influence of seal type and substrate type on pre-acclimatization, and symptomatological aspects relating to acclimatization of ipê-roxo. For the pre-acclimatization, ipê-roxo plants obtained through an in vitro zygotic embryo culture were aseptically inoculated in test tubes with different types of seal (cotton plug, plastic cap + parafilm and plastic lid) and different substrates (agar, vermiculite and Plantmax®) supplemented with a WPM culture medium with 1 gL-1 of activated charcoal, 10 mgL-1 of citric acid and 30 gL-1 of sucrose added. For the acclimatization, in vitro ipê-roxo plants were transplanted into 56-cm³plastic tubes containing vermiculite and Plantmax®at a 2:1 ratio which had been previously autoclaved at 121ºC and 1 atm for 20 minutes. Once transplanted, the plants were irrigated with different concentrations of the MS medium (25%, 50%, 75%, 100% and 150%), using distilled water as control. After 30 days, the effects of seal type and substrate type on pre-acclimatization were examined. Cotton can be recommended where Plantmax®or vermiculite is used as substrate. In the acclimatization it was noted that where plants were irrigated with distilled water and concentrations < 50% they showed symptoms of nutritional deficiency. Similar symptoms were observed when using MS medium at a concentration equal to or greater than 100%. The 75% MS concentration was found to be the most effective at maintaining the nutritional vigor of ipê-roxo seedlings in the process of acclimatization.