SUMMARY Cordia trichotoma, popularly known in Brazil as ‘louro-pardo’, has numerous environmental and timber-related applications. This species is naturally propagated by seeds; however, this form of propagation results in restricted seedling production due to high genetic variability associated with a low degree of forest improvement. Thus, cloning of selected adult trees is an alternative for producing high-quality plants. The aims of this work were to evaluate the emission of epicormic shoots from pruned branches and to define a protocol for the in vitro establishment of C. trichotoma selected adult trees. Propagules used in these experiments were derived from the selection of four C. trichotoma adult trees. The branches were placed in a greenhouse to induce epicormic shoots. Number of shoots according to the climatic season (autumn and spring) and shoot collection time were evaluated. Three sodium hypochlorite concentrations were evaluated for five minutes (C1 = 0.58 % active chlorine, C2 = 1.12 % active chlorine, and C3 = 2.12 % active chlorine) for in vitro establishment. Results indicated that the epicormic shoot technique could be considered viable for shoot emission of C. trichotoma, regardless of the climatic season (autumn or spring). Sodium hypochlorite solution applied for 5 minutes (1.12 % of active chlorine) was effective for the in vitro establishment of nodal segments from epicormic shoots, resulting in 61.3 % of established explants. These results are promising for the cloning of adult trees during the mature stage of development in the field without the need to cut the selected tree.

RESUMEN: Cordia trichotoma, conocida popularmente en Brasil como "louro-pardo", tiene numerosas aplicaciones ambientales y madereras. Esta especie se propaga naturalmente por semillas; sin embargo, esta forma de propagación resulta en una producción restringida de plántulas por la alta variabilidad genética asociada con un bajo grado de mejoramiento forestal. La clonación de árboles adultos seleccionados es una alternativa para producir plantas de alta calidad. El objetivo de este trabajo fue evaluar la emisión de brotes epicórmicos de ramas podadas y definir un protocolo para el establecimiento in vitro de árboles adultos seleccionados. Los propágulos utilizados se derivaron de la selección de cuatro árboles adultos y las ramas se colocaron en un invernadero para inducir brotes epicórmicos. Se evaluó el número de brotes según la época climática (otoño y primavera), el tiempo de recolección de los brotes, y tres concentraciones de hipoclorito de sodio durante cinco minutos (C1 = 0,58 % de cloro activo, C2 = 1,12 % de cloro activo y C3 = 2,12 % de cloro activo) para el establecimiento in vitro. Los resultados indicaron que la técnica de brotes epicórmicos podría considerarse viable para la emisión de brotes independientemente de la estación climática. La solución de hipoclorito de sodio (1,12 % de cloro activo) fue eficaz para el establecimiento in vitro de segmentos nodales de brotes epicórmicos, resultando en un 61,3 % de explantes establecidos. Los resultados son prometedores para la clonación de laureles durante la etapa madura de desarrollo en el campo sin necesidad de cortar el árbol seleccionado.

ABSTRACT Background: We have developed a micropropagation technique methodology to clonal micro-garden formation of Bambusa vulgaris selected adult plant. Collection site (i.e., stock plant cultivated in different environments) and seasonality of shoot collection (i.e., months of the year) effects on in vitro culture were evaluated. Explants that showed normal development were ex vitro rooted in mini-incubator system, and three culture media (WPM, MS and deionized water + agar) supplemented with plant growth regulators (IBA, NAA and BAP) and antibiotic (streptomycin sulphate and culture medium free - control) were evaluated. Micropropagated plants were acclimatized in a shadow house and transferred to a semi-hydroponic system for establishment of a clonal micro-garden. The efficacy of the cloning protocol was determined with genetic fidelity analysis by ISSR molecular markers. Results: Considering all inoculations, 21.9% of nodal segments were in vitro established in nine shoot collections. The rooting percentage was 36.6%, and no interactions were observed between the use of culture medium and antibiotic. Culture medium free antibiotic resulted in 80.0% of survival and 50.0% of adventitious rooting. Micropropagated plants presented adequate growth and adaptation to ex vitro conditions in the clonal micro-garden. Molecular analyses by ISSR markers indicated the absence of genetic variations, and histological analyses revealed normal adventitious root formation originating from meristematic cells. Conclusion: The formation of a clonal micro-garden was demonstrated, proving the feasibility of the tested technique. Our results contribute to the development of a clonal propagation protocol for B. vulgaris selected adult plants.

SUMMARY: Few studies have focused on the in vitro multiplication methods for Eucalyptus cloeziana. In this work we developed an indirect organogenesis protocol to obtain micropropagated plants. The interactions of plant growth regulators in juvenile tissues were evaluated. Hypocotyl, cotyledon and root tissues obtained from in vitro germinated seedlings were subjected to combinations of α-naphthaleneacetic acid (NAA), thidiazuron (TDZ) and 2,4-dichlorophenoxyacetic acid (2,4-D). In vitro callogenesis, adventitious bud induction, shoot elongation, and ex vitro survival and rooting were evaluated. Callogenic structures were observed in all evaluated tissues. Morphogenic characteristics related to the meristematic center was observed. The tissues that presented the callus mass were subcultured in a regeneration culture medium supplemented with 1.0 mg L-1 of 6-benzylaminopurine (BAP). Only hypocotyl and cotyledon induced adventitious bud and shoot elongation. Hypocotyl subjected to 2.0 mg L-1 TDZ had the highest number of elongated shoots. The two tissues (i.e., hypocotyl and cotyledon) combined with thidiazuron were characterized by the ex vitro survival of microcuttings and by adventitious rooting. Results confirmed tissue culture efficiency for microplants production by indirect organogenesis from hypocotyl and cotyledon cultivated with TDZ, and its implementation can be an alternative for forest tree breeding programs of E. cloeziana.

RESUMEN: Pocos estudios se han centrado en los métodos de multiplicación in vitro para Eucalyptus cloeziana. En este trabajo se desarrolló un protocolo de organogénesis indirecta para obtener plantas micropropagadas. Se evaluaron las interacciones de los reguladores del crecimiento en tejidos juveniles. Los tejidos del hipocótilo, cotiledón y raíces obtenidos de plántulas germinadas in vitro se sometieron a combinaciones de ácido α-naftaleneacético (ANA), tidiazurón (TDZ) y ácido 2,4-diclorofenoxiacético (2,4-D). Se evaluaron la callogénesis in vitro, la inducción adventicia de yemas, el alargamiento de brotes, y la sobrevivencia y enraizamiento ex vitro. Se observaron estructuras calogénicas en todos los tejidos evaluados. Se observaron características morfogénicas relacionadas con la formación de centros meristemáticos. Los tejidos que presentaron la masa del callo fueron subcultivados en medio de cultivo de regeneración suplementado con 1,0 mg L-1 de 6-bencilaminopurina (BAP), y solo los tejidos del hipocótilo y cotiledón formaron yemas adventicias y brotes alargados. Los tejidos del hipocótilo sometidos a 2,0 mg L-1 de tidiazuron obtuvieron mayor número de brotes alargados. Los dos tejidos (hipocótilo y cotiledón) combinados con TDZ se caracterizaron por sobrevivencia y el enraizamiento adventicio ex vitro de las microestacas. Los resultados confirmaron la eficiencia del cultivo de tejidos para la producción de microplantas por organogénesis indirecta a partir de tejidos del hipocótilo y cotiledón cultivados con TDZ y su implementación puede ser una alternativa para los programas de mejoramiento forestal de E. cloeziana.

Resumo Visando fornecer informações que sirvam de base para estudos de melhoramento genético de Eucalyptus foi realizada a análise da diversidade genética usando marcadores ISSR. As espécies estudadas foram Eucalyptus urophylla e Eucalyptus microcorys, ambas com potencial econômico florestal. Os indivíduos estudados pertencem a um teste de espécies e procedências instalado no ano de 1974 e permanecem isentos de tratos silviculturais. Para as análises foram utilizados nove primers ISSR universais. A partir dos resultados avaliou-se a existência de variação intra e interespecífica por meio da porcentagem de polimorfismo, conteúdo de informação polimórfica (PIC) e distância Euclidiana entre indivíduos. A fim de analisar a distância Euclidiana entre os indivíduos foram feitas a análise de coordenadas principais (PCoA) e análise permutacional de dispersão multivariada (PermDisp) seguida pelo teste de Tukey. Observou-se elevada porcentagem de polimorfismo (57,14% para Eucalyptus microcorys e 80,95% para Eucalyptus urophylla). Considerando todos os grupos avaliados, os valores de PIC foram superiores a 0,5 para quatro primers (UBC827, UBC835, UBC841). A variabilidade interna foi significativamente maior na população de Eucalyptus urophylla em relação à Eucalyptus microcorys, o que pode estar associado à maior capacidade do Eucalyptus urophylla em hibridizar naturalmente.

Abstract Here, we deployed a genetic diversity analysis using ISSR markers in two Eucalyptus species, as a fundamental step toward breeding strategies. The selected species were Eucalyptus urophylla and Eucalyptus microcorys, both with economic potential in forestry. The studied individuals belong to a species and the provenance test that was installed in 1974 and until now remains exempt from silvicultural treatments. Nine universal ISSR primers were used in the analyses. Intra and interspecific variation through the polymorphism percentage, polymorphism information content (PIC) and Euclidean distances among individuals were computed. The Euclidean distance among the individuals was used to perform a principal coordinate analysis (PCoA), as well as the permutation analysis of multivariate dispersion (PermDisp), followed by the Tukey’s test. A high percentage of polymorphic bands were detected, with 57.14% for Eucalyptus microcorys and 80.95% for Eucalyptus urophylla. PIC values were higher than 0.5 for four primers (UBC827, UBC835, UBC841, and UBC842). The genetic variability was significantly higher within the Eucalyptus urophylla population than in Eucalyptus microcorys, which may be associated with the greater ability of Eucalyptus urophylla to naturally hybridize, therefore, enabling the introduction of new alleles to their populations.

RESUMO A importância de espécies dos gêneros Eucalyptus e Corymbia vem sendo evidenciada nos programas de silvicultura, principalmente pela adaptação em diversas condições ambientais e pelos múltiplos produtos que podem ser obtidos. Como a seleção e a clonagem de indivíduos superiores geralmente são realizadas na fase adulta, o desenvolvimento e a adequação de técnicas de propagação vegetativa que possibilitem o resgate e o estabelecimento in vitro de espécies desses gêneros são necessários. Dessa forma, o presente estudo teve como objetivo induzir brotos epicórmicos a partir de ramos podados de árvores adultas e promover o estabelecimento in vitro de nove espécies, sendo seis do gênero Eucalyptus e três de Corymbia. O material utilizado para a obtenção dos explantes foi proveniente da seleção de duas matrizes de cada espécie com 44 anos de idade, oriundas da implantação de um teste de espécies e procedências. Foram avaliados o número de gemas e brotos de cada ramo aos 15, 25, 35 e 45 dias após o início do experimento em casa de vegetação. De acordo com os resultados, a indução de brotações epicórmicas a partir de ramos podados foi considerada uma técnica viável e eficiente para obter fontes de propágulos de matrizes adultas de todas as espécies, apresentando um aumento gradual das características avaliadas ao longo do tempo. Além disso, o cultivo in vitro é uma alternativa eficaz para estabelecer propágulos a partir de brotações epicórmicas de árvores adultas da maioria das espécies avaliadas, com estabelecimento de até 62,5%. Contudo, para Corymbia citriodora (Hook.) K.D. Hill & L.A.S Johnson e Eucalyptus tereticornis Smith é necessário o desenvolvimento de mais estudos para viabilizar o estabelecimento in vitro.

ABSTRACT The importance of Eucalyptus and Corymbia has been evident in forestry programs, mainly due to their adaptation to various environmental conditions and the multiple products that can be obtained. As the selection and cloning of superior individuals are usually performed in adulthood, the development and adaptation of the vegetative propagation techniques that enable the rescue and in vitro establishment of species are necessary. Thus, the present study aimed to induce epicormic shoots from pruned branches of adult trees and to promote the in vitro establishment of nine species: six of Eucalyptus and three of Corymbia. The material used to obtain the explants came from the selection of two 44-year-old mother plants of each species, from species, and provenance tests. The number of buds and shoots of each branch was evaluated at 15, 25, 35, and 45 days after the beginning of the experiment in a greenhouse. According to the results, the induction of epicormic shoots from pruned branches was considered a viable and efficient technique to obtain propagule sources from adult mother plants of all species, presenting a gradual increase in the evaluated characteristics over time. Also, in vitro culture is an effective alternative to improve the propagation of the evaluated species, with an establishment of up to 62.5%. However, for Corymbia citriodora (Hook.) K.D. Hill & L.A.S Johnson and Eucalyptus tereticornis Smith it is necessary to develop further studies to enable the in vitro establishment.

ABSTRACT The relevance of Eucalyptus dunnii has been evidenced mainly for its wood quality and cold tolerance among cultivated subtropical eucalypts. However, rooting is a challenge for its propagation, particularly when adult material is involved. This study aimed to assess the mixotrophism on the in vitro elongation and adventitious rooting phases in Eucalyptus dunnii microcutting. The experimental material used was obtained from a ministumps of Eucalyptus dunnii clones. In order to evaluate gas exchange and sucrose supplementation on in vitro elongation and adventitious rooting, the experiment was prepared in a 3×4 factorial arrangements with three forms of sealing (rigid polypropylene caps with no membrane (0/M), with a membrane (1/M), with three membranes (3/M) and four sucrose concentrations (0, 10, 20 and 30 g.L-1). At 30 days in the elongation phase it was evaluated (length, number of shoots per explant, oxidation, bud vigor, pigment content, leaf area and anatomy) and rooting (length, root diameter and rooting). Results show that sucrose should be added in the culture medium for in vitro elongation and can be reduced to concentrations between 10 and 20 g.L-1. In vitro rooting requires the use of 30 g.L-1 of sucrose. The use of flasks with membranes that allow gas exchange is an effective alternative to promote the in vitro elongation and adventitious rooting of Eucalyptus dunnii microcutting.

Abstract The objectives of this research were to verify the relationships between the dendrometric and edaphic variables with the yield of oleoresin from Copaifera spp., and to adjust equations to predict yield from a primary forest. Thirty Copaifera spp. trees were selected to extract oleoresins over 24 hours, using a 1.91 cm (¾ inch) auger. In addition, data were collected on tree size and the edaphic characteristics of the topsoil around of each tree. Principal components analysis was used to verify the relationships between variables and a regression analysis was used to verify variables that may be best to predict oleoresin yield. After the principal components analysis, the only variable related to the oleoresin yield was the stem height, which had the best adjusted coefficient of determination (0.84) and relative standard error (13.11%). We found the yield of oleoresin from Copaifera spp. in primary a forest had a significant and positive correlation with the stem height, whereas no significant correlations were found between yield, or any other dendrometric or topsoil variables studied.

Resumen El objetivo de este estudio fue investigar la relación entre las variables dendrométricas y del suelo con el rendimiento de aceite de Copaifera spp. y ajustar una ecuación para predecir la productividad en bosque primario. En el área de la investigación, 30 árboles de Copaifera spp. fueron seleccionados como muestras para la extracción del aceite por un período de 24 horas, con el uso de la barrena con 1,91 cm (3/4"). Además, fueron colectadas informaciones sobre el tamaño de los árboles y las características del suelo superficial en los alrededores de cada árbol. Se aplicó el análisis de componentes principales para verificar la relación de las variables con el rendimiento de aceite y, posteriormente, fue ajustada una ecuación para predecir este rendimiento mediante análisis de regresión. La única variable relacionada con el rendimiento de aceite fue la altura del fuste, y fue selecionada como el modelo que presentó mejor coeficiente de determinácion (0,84) y error típico de estimación (13,11%). Por lo tanto, se concluyó que el rendimiento del aceite de Copaifera spp. en bosque primario tiene una correlación positiva y significativa con la altura del fuste, mientras que las otras variables dendrométricas y del suelo superficial no presentaron correlación significativa con el rendimiento de aceite.

ABSTRACT Khaya senegalensis, is a promising species for forest production, as it has excellent timber properties and adapts well to local edaphoclimatic conditions. To achieve better results in plant production and growth, some factors are important, such as nutrients, water and light. Light interferes directly with photosynthesis, plant growth and biomass. This study aims to investigate the morphological response and nutrient accumulation in seedlings of Khaya senegalensis under luminosity levels. An experiment was installed in the forest nursery during 150 days. The seedlings were distributed in a completely randomized design with five treatments in luminosity levels (full sun, 70%, 50%, 30% and natural shade), and 16 replicates. Height and diameter were measured in 30 days intervals. At the end of the experiment, mass weights (leaf, stem, root and total) were measured, and the root-shoot ratio and seed quality index proposed by Dickson were calculated. The accumulated macro and micronutrient contents were determined from the dry leaf material. The highest plants, diameters and total dry matter were found at levels of 70%, 50%, 30%, respectively. Plants exposed to natural shade grew less, in relation to plants with higher luminosity levels. As for nutrient accumulation, plants under natural shade accumulated higher levels of iron, while plants in the full sun accumulated more nitrogen contents. Plants with partial light conditions (70%, 50%, and 30%) were heavier in total biomass. Thus, the initial growth of Khaya senegalensis in low light conditions is compromised, whereas partial luminosities favor the growth and quality of seedlings.

ABSTRACT We addressed a major challenge in the in vitro clonal propagation of Corymbia citriodora, Eucalyptus urophylla and E. benthamii by using an ex vitro adventitious rooting strategy in a mini-incubator. Mini-incubators were placed in four environments for rooting. A shade house with no fogging system and a greenhouse with no ventilation but with a fogging environment had the best performance in terms of rooting, root growth and survival of microcuttings. Daily recording of the temperature within each mini-incubator in each environment allowed the verification of negative correlations between the maximum average temperature and the survival, adventitious rooting and root growth. The ideal maximum air temperature for the efficient production of clonal plants was 28.4°C (± 5.5°C), and the minimum was 20.3°C (± 6.2°C). E. benthamii was more sensitive to higher temperatures than C. citriodora and E. urophylla. Nevertheless, placing mini-incubators in the shade house with no fogging system resulted in a stable and uniform performance among the three species, with 100.0% survival and 81.4% rooting. Histological sections of the adventitious roots revealed connection with the stem vascular cambium. Therefore, our experimental system demonstrated the potential of mini-incubators coupled with the proper environment to optimize the adventitious rooting performance of microcuttings.

ABSTRACT Copaiba trees, of the genus Copaifera (Fabaceae), produce an oleoresin that has pharmacological applications. The yield from the trees is very variable, and factors affecting production are still unknown. We evaluated the yield of oleoresin from Copaifera spp. in the Cerrado- Amazonia ecotone, as well as its relationship with the growth and age of trees. We sampled 30 Copaifera trees by extracting oleoresin for 24 h with a metal borer. Increment cores were collected from 15 trees to determine their age by counting growth rings and to calculate the mean annual increment of the diameter at breast height. The cylinders were sanded and the number of growth rings was counting with a magnifying glass (10x). The ages of trees from which increment cores were not collected were estimated by simple regression analysis. The proportions of productive and non-productive trees were recorded. The best adjusted model for age estimation showed R²adjust. = 0.616 and Syx% = 4.42. The average productivity of oleoresin was 0.124 L per day, and 30% of the trees were productive. The proportion of productive trees increased with increasing diameter at breast height and age, but after a point, increasing diameter was associated with reduced productivity. The mean annual increment had an inverse relationship with diameter for the productivity of oleoresin. The results suggest that other factors could be triggering and controling the oleoresin production and not only the age.

RESUMO: As raízes de Cochlospermum regium são usadas na medicina popular, pois seu extrato apresenta diversas moléculas fitoquímicas, algumas com atividade antimicrobiana, que, consequentemente, expõe esta espécie ao risco de erosão genética. Assim, o objetivo deste estudo foi elaborar um protocolo de multiplicação in vitro para explantes de C. regium usando esterilização química do meio de cultura. Gemas apicais obtidas de plântulas de C. regium germinadas in vitro foram inoculadas em meio de cultivo MS suplementado com 0,05mg L-1 de ANA e 1mg L-1 de BAP e esterilizado pela adição do agente químico hipoclorito de sódio (NaOCl) nas concentrações de cloro ativo de 0,001%, 0,003% e 0,005%. O meio autoclavado foi utilizado como controle. Os resultados mostraram que a contaminação por bactérias aos 91 dias de cultivo foi significativamente (P<0,05) controlada pela autoclavagem, 0,001% e 0,005% de cloro ativo. Além disso, a indução de calos no meio de cultura com 0,001% e 0,005% de cloro ativo foi, respectivamente, 30% e 20% maior do que na esterilização por autoclavagem. Não houve diferença significativa (P<0,05) da porcentagem de indução de brotos entre os métodos de esterilização e 65% dos explantes sobreviveram na presença de 0,005% de cloro ativo. Análises histológicas indicaram que o cloro ativo não afetou os eventos morfogênicos. Os resultados indicaram que a esterilização química por meio do uso de 0,001% - 0,005% de cloro ativo auxiliou no controle da proliferação de bactérias e fungos no meio de cultura e não afetou o desenvolvimento dos explantes de C. regium, tornando-a uma alternativa em relação a autoclavagem.

ABSTRACT: Cochlospermum regium roots are used in popular medicine and its extract has diverse phytochemical molecules some with antimicrobial activity, consequently exposing this specie to genetic erosion risks. Thus, the objective of this study was to develop an in vitro multiplication protocol using chemical sterilization of culture medium. Therefore, explants obtained from apical buds of C. regium seedlings were inoculated into with 0.05mg L-1 NAA and 1mg L-1 BAP sterilized by chemical agent sodium hypochlorite (NaOCl) at 0.001%, 0.003% and 0.005% of active chlorine (Cl). Autoclaved culture medium was used as control. Result showed that the contamination by bacterial at 91 days of cultivation was significantly (P<0.05) controlled by autoclaving, 0.001% and 0.005% Cl. Moreover, the callus induction in the culture medium with 0.001% and 0.005% Cl was, respectively, 30% and 20% major than autoclaving sterilization. There was not significant (P<0.05) in the percentage of shoot induction among the sterilization preparations methods, and 65% of the explants survived in the presence of culture medium with 0.005% Cl. Histological analyses indicated that the Cl did not have any deleterious effects on morphogenic events. These results indicated that the chemical sterilization using 0.001% - 0.005% Cl controlled the fungal and bacterial multiplication in the culture medium and no affected the C. regium explants development, becoming it an alternative to autoclaving method.

ABSTRACT Nidularium procerum and Nidularium innocentii (Bromeliaceae) were cultivated in vitro on media supplemented with different sources and levels of GA3 (gibberellic acid). These sources were the commercial powder (analytical degree) and fermented extract obtained by Fusarium moniliforme via solid state fermentation. The in vitro elongation and rooting of these plants were evaluated after 50 days of cultivation. The GA3 present in the fermented extract possess the same effect of purified GA3 (analytical degree) for the increase of the height of aerial part of shoots of N. innocentii, but not for the N. procerum being the GA3 fermented extract in a lesser degree. The GA3 fermented extract influences negatively the rooting in N. innocentii, while GA3 analytical degree practically does not interfere in the rooting. On the other hand, in N. procerum, both the GA3 sources reduce the root number and do not interfere in rooting percentage. GA3 crude fermented extract is an alternative to reduce costs, however, its results can vary depending on the species and parameter evaluated. The fermented extract was stored at temperature during 260 days and its shelf life presented a suitable stability, maintaining 92% of its initial GA3 amount.

SUMMARY: We evaluated the supplementation of the MS culture medium with active chlorine and activated charcoal for the in vitro culture of Bambusa vulgaris. Lateral shoots were collected from field-cultivated plants to obtain explants, which consisted of nodal segments of 1-2 cm length, containing one axillary bud. The MS culture medium was supplemented with the following treatments: E1= 0.004 % v v-1 of active chlorine + 4 g L-1 of charcoal; E2= 0.004 % v v-1 of active chlorine; E3= 4 g L-1 charcoal and E4= control (no active chlorine and no charcoal). The percentage of oxidation, fungal and bacterial contamination, explant establishment, survival, sprout and adventitious rooting were evaluated every 21 d, during 63 d. The use of active chlorine reduced the fungal (28 %) and bacterial (38 %) contamination, being the treatment with the highest percentage of established explants (16 %), survival (68 %) and sprout induction (95 %) after 63 d. After 36 days from the beginning of the multiplication stage, some explants presented spontaneous rooting, without the application of plant growth regulators. An anatomical analysis of sprouts and roots revealed the presence of meristematic zones. Furthermore, it indicated that the emergence of adventitious roots occurred from the nodal region in association with axillary buds. Our results contribute toward the development of more efficient protocols for the in vitro propagation of B. vulgaris, from which we recommend using active chlorine for further assessments.

RESUMEN: En el estudio se evaluó el suplemento de cloro activo y carbono activado en el cultivo in vitro de Bambusa vulgaris. Brotes laterales fueron colectados de las plantas cultivadas en el campo para obtener explantes. Los explantes consistieron en segmentos nodales de 1-2 cm de longitud que contenían una yema axilar. El medio MS se suplementó con los siguientes tratamientos: E1 = 0,004 % v v-1 de cloro activo + 4 g L-1 de carbón; E2 = 0,004 % v v-1 de cloro activo; E3 = 4 g L-1 de carbón y E4 = control (sin suplemento con cloro activo y sin carbón). El porcentaje de oxidación, la contaminación por hongos y bacterias, el establecimiento del explante, la supervivencia, la inducción del brote y enraizamiento se evaluaron durante 63 días. El uso de cloro activo redujo la contaminación por hongos (28 %) y bacterianas (38 %), siendo el tratamiento con mayor porcentaje de explantes establecidos (16 %), supervivencia (68 %) y inducción de brotes (95 %). Después de 36 días, algunos explantes presentaron enraizamiento espontáneo, sin aplicación de reguladores de crecimiento. Un análisis anatómico de los brotes y raíces mostró zonas meristemáticas, la conexión entre el sistema vascular del tallo y las hojas y la aparición de raíces adventicias en la región nodal en asociación con los brotes axilares. Los resultados contribuyen al desarrollo de protocolos más eficientes para la propagación in vitro de B. vulgaris, de los cuales se recomienda el uso de cloro activo para futuras evaluaciones.

RESUMO. Objetivou-se estudar a composição florística e estrutural de um fragmento secundário de Floresta Estacional Semidecidual em Tapurah (Estado do Mato Grosso, Brasil). Aplicou-se o método de área fixa com conglomerados de dimensões de 10 × 250 m, sendo alocados e medidos cinco conglomerados com cinco subunidades de 500 m² cada. Foram consideradas as espécies com diâmetro à altura do peito superior ou igual a 10 cm e verifirada a suficiência amostral do levantamento florístico pela curva espécie-área. A similaridade florística entre as subunidades amostrais foi obtida com o Índice de Jaccard e a diversidade de espécies pelos Índices de Diversidade de Shannon e Equabilidade de Pielou. Para caracterização da estrutura horizontal da vegetação foram utilizados a densidade, frequência e dominância, relativas e absolutas, e os valores de importância ecológica e a estrutura diamétrica pelo procedimento de Spiegel. Destacou-se a elevada representatividade das famílias Vochysiaceae, Fabaceae e Sapindaceae e como as mais importantes as espécies Qualea paraensis, Aspidosperma discolor e Matayba arborescens. Foi verificada elevada diversidade e baixa dominância ecológica das espécies e a estrutura diamétrica das árvores apresentou distribuição exponencial negativa. A estrutura, composição florística e riqueza da vegetação corresponde a de floresta com comunidade estável e autorregenerativa após a extração seletiva.

ABSTRACT. This study was conducted in one region of a Seasonal Semideciduous Forest located in Tapurah (Mato Grosso State, Brazil) with the aim of studying its floristic and structural composition. The fixed area method was applied to 10 × 250 m clusters, allocating and measuring five clusters with five subunits of 500 m² each. Species with a diameter at breast height greater than or equal to 10 cm were considered, and the sample sufficiency of the floristic survey was verified by a species accumulation curve. The similarities between the sample subunits were calculated by the Jaccard Similarity Index, and the species diversity with the Shannon Diversity Index and Pielou Evenness Index. The horizontal vegetation structure was characterized by density, frequency, dominance and the values of ecological importance, and diametric distribution were assessed by the Spiegel procedure. The families Vochysiaceae, Fabaceae and Sapindaceae were highly represented, and Qualea paraensis, Aspidosperma discolor and Matayba arborescens were the most important species. A high diversity and low ecological dominance were found, and the diametric structure of the trees presented a negative exponential distribution. In general, the structure, floristic composition and richness of vegetation correspond to a forest with stable and autoregenerative community after selective logging.

Abstract The aim of this study was to develop a shoot regeneration protocol for Tectona grandis by examining the effects of pretreatments, regeneration culture medium, adventitious rooting, and acclimatization. The best organogenic potential was achieved when hypocotyls and cotyledonary segments from seedlings germinated on a medium containing TDZ, were cultured for four weeks on MS medium supplemented with BAP/GA3. With TDZ pretreatment during seed germination, up to 70% of the cotyledonary segments (0.5 TDZ pretreatment and 1.0 BAP + 0.5 GA3 during regeneration, mg L-1) and 60% of the hypocotyl explants (0.1 TDZ pretreatment and 1.0 BAP + 0.5 GA3 during regeneration, mg L-1) resulted in shoot regeneration. Finally, 65% of the regenerated shoots rooted, of which 60% were successfully acclimatized ex vitro. Our protocol increases regeneration efficiency for teak and it can serve as a platform for genetic transformation to improve this important tree species.