ABSTRACT This study aimed to identify the correlations between traits of the groups stem cutting, seedling, stem, and root of cassava. Length, diameter, and weight of stem cutting (Group 1) were measured at each growing season (July, August, September, and October). A total of 300 cuttings were collected after sprouting and planted at seasons of September 22, October 7 and 19, and November 25. Plant height at planting, number of leaves at planting, and number of leaves at 7 days after planting were measured. The number of leaves at transplanting and plant height at transplanting were determined after acclimation (Group 2). Seedling transplanting was carried out on November 9 and 24 and December 3 and 26, and the traits stem (Group 3) and root (Group 4) yield were measured at harvest. Associations between the groups stem cutting and seedling were established by stem cutting diameter and weight, and height and number of leaves at planting. Seedling traits had the greatest influence on the number of buds per stem and stem diameter. Main stem branching height and stem diameter can be used for selecting plants with an indication of the best quality and yield of root traits.

ABSTRACT Microsatellites are short sequence repeats that make up the genomes of eukaryotes and prokaryotes. They are of great importance as DNA markers for studies in several fields of genetics. In the present review, we searched for studies published in the five years period of 2017 to 2021 regarding the use of microsatellites in studies with forest tree species from the Brazilian biomes, in order to examine the importance of these markers for forest resources conservation. We searched scientific papers in journals indexed on the Scopus and Web of Science databases. There were found 38 peer reviewed articles that used microsatellites in the Brazilian biomes. The Atlantic Forest was the biome with more studies (35.9 %) and most of the studies were published in 2018 (34.2 %). In addition, most of the studied species belonged to the Fabaceae family (34.2 %). The conclusions and recommendations made in these studies ratify the great contribution of microsatellite markers in the conservation of native forest species in Brazilian biomes.

RESUMO A lavanda (Lavandula dentata) possui diversas aplicações medicinais, tanto in natura como após processamento industrial. O incremento à produtividade pode ser obtido por meio da propagação massal, ampliando a possibilidade de obtenção de matéria prima para a produção de óleo essencial. O objetivo deste trabalho foi desenvolver um protocolo de micropropagação a partir de explantes obtidos de sementes. Foram avaliados aspectos da germinação, multiplicação, alongamento e enraizamento in vitro e, em seguida, o processo de aclimatização das mudas. A germinação in vitro de lavanda pôde ser obtida apenas com a utilização do meio composto por ágar e água. Para a multiplicação, o uso de meio MS (Murashige & Skoog, 1962) acrescido de 5,0 µM de 6-benzilaminopurina ao meio nutritivo é o mais apropriado. Para o alongamento e enraizamento, a utilização de reguladores de crescimento é dispensável. A aclimatização pode ser obtida diretamente com a transferência do explante para sacos plásticos com substrato, mantidos em casa de vegetação. Foi possível desenvolver um protocolo para o cultivo in vitro (estabelecimento, multiplicação, alongamento, enraizamento e aclimatização) de lavanda a partir de explantes de sementes.

ABSTRACT Lavender (Lavandula dentata) has several medicinal applications, both in the fresh form and after industrial processing. Productivity increase could be obtained through the mass propagation, expanding the possibility of obtaining raw material for production of essential oil. The objective of this work was to develop a micropropagation protocol from explants obtained from seeds. Aspects of in vitro germination, multiplication, elongation and rooting were evaluated and, in sequence, the acclimatization process as well. The in vitro germination of lavender seeds can be obtained using a medium composed of agar and water. For multiplication, the use of MS medium (Murashige & Skoog, 1962) added with 5.0 µM 6-benzylaminopurine to the nutrient medium is the most appropriate. For elongation and rooting, the use of growth regulators is unnecessary. Acclimatization can be obtained directly by transferring the explant to plastic bags with substrate, kept in a greenhouse. It was possible to develop a protocol for the in vitro cultivation (establishment, multiplication, elongation, rooting and acclimatization) of lavender from explants of seed origin.

Abstract In agricultural experiments, measuring all plants that constitute an experimental unit is the most appropriate method for estimating averages. This study analyzed sample sizes (number of plants) for estimating averages of agronomic traits in cassava. The experiment for seedling production was conducted on four sowing dates: September 22, October 7, October 19, and November 25, 2017. The evaluated characters were plant height at planting, number of leaves at planting, number of leaves at 7 days after planting, number of leaves at transplanting, and plant height at transplanting. The seedlings were transplanted to the field on November 9, November 24, December 3, and December 26. Root characteristics and root yield were measured at harvest. The following statistics were measured: minimum, maximum, range, mean, median, variance, standard deviation, and coefficient of variation. The sample size was determined by resampling with replacement when the range of the 95% confidence interval (CI) was 10%, 20%, 30%, and 40% of the average estimate. Larger sample sizes were needed to estimate trait averages with a 95% CI range of 10% of the average estimate, i.e., when estimation accuracy was higher. In contrast, lower sample sizes were required to estimate averages of all characters in all planting times with a 95% CI range of 40%. For measuring seedling production and stem and root yield, 63 and 153 plants are sufficient to estimate averages when the range of the 95% confidence interval was 20%.

Resumen En experimentos agrícolas, medir todas las plantas que constituyen una unidad experimental es el método más apropiado para estimar promedios. Este estudio analizó tamaños de muestra (número de plantas) para estimar promedios de caracteres agronómicos en yuca. El experimento para la producción de plántulas se realizó en cuatro fechas de siembra: 22 de septiembre, 7 de octubre, 19 de octubre y 25 de noviembre de 2017. Los caracteres evaluados fueron la altura de la planta en la siembra, el número de hojas en la siembra, el número de hojas a los 7 días después de la siembra, el número de hojas en el trasplante y la altura de la planta en el trasplante. Las plántulas se trasplantaron al campo el 9 de noviembre, 24 de noviembre, 3 de diciembre y 26 de diciembre. Las características de la raíz y el rendimiento de la raíz se midieron en la cosecha. Se midieron las siguientes estadísticas: mínimo, máximo, rango, media, mediana, varianza, desviación estándar y coeficiente de variación. El tamaño de la muestra se determinó mediante remuestreo con reemplazo cuando el rango del intervalo de confianza (IC) de 95% fue de 10%, 20%, 30% y 40% de la estimación promedio. Se necesitaron tamaños de muestra más grandes para estimar los promedios de rasgos con un rango de IC de 95% de 10% de la estimación promedio; es decir, cuando la precisión de la estimación fue mayor. En contraste, se requirieron tamaños de muestra bajos para estimar promedios de los caracteres en los tiempos de siembra con un rango de IC de 95% de 40%. Para medir la producción de plántulas y rendimiento de tallos y raíces, 63 y 153 plantas son suficientes para estimar promedios cuando el rango del intervalo de confianza de 95% fue de 20%.

ABSTRACT. A study was conducted during four growing seasons to investigate the rooting capacity and survival percentage of cassava seedlings from stem cuttings selected based on their number of leaves. The experimental design was a randomized block design with five replications in a factorial scheme (4 × 2 × 2), totalling 16 treatments. Treatments consisted of combinations of growing season (September 22, October 7 and 19, and November 25), stem cuttings smaller (15 to 19.99 mm) and larger (20 to 25 mm) than 20 mm in diameter, and number of leaves on the stem cuttings (3 to 5 and 6 to 8 leaves). The experiment was carried out during the four growing seasons in a Van der Hoeven greenhouse. The greenhouse, as well as the benches on which the treatments were placed, had a north-south orientation. The greenhouse has an automatic mist irrigation system, and the mean temperature was 25 °C. The plant height at planting, number of leaves at planting, and number of leaves at 7 days after planting were measured. The final number of leaves, final plant height, shoot dry matter, root dry matter, and total dry matter were measured after acclimatization. Stem cuttings between 20 and 25 mm in diameter should be used to produce cassava seedlings with the rapid multiplication method. Cuttings with 6 to 8 visible leaves should be collected, and the cuttings should be planted at the end of September.

Resumo Eugenia involucrata é uma espécie florestal nativa do Brasil com grande potencial para uso madeireiro, frutícola e medicinal. O presente estudo objetivou avaliar a influência de fitorreguladores e da luminosidade sobre a calogênese em discos foliares de Eugenia involucrata. Foi conduzido um experimento bifatorial (2x5), cujos tratamentos consistiram na combinação da ausência ou presença de luz durante o cultivo e de cinco diferentes empregos de fitorreguladores: ANA, 2,4-D, BAP e as combinações ANA + BAP e 2,4-D + BAP, todos a 5 μM, em meio nutritivo MS. Após 45 dias de cultivo in vitro foi observado que a ausência de luz durante o período de cultivo reduz a oxidação fenólica favorecendo, assim, a calogênese , especialmente na presença de ANA e das combinações ANA + BAP e 2,4-D + BAP. O uso de 2,4-D e de BAP, isoladamente, não é favorável à calogênese em discos foliares de Eugenia involucrata.

Abstract Eugenia involucrata is a native forest species from Brazil with great potential for timber, fruit and medical purpouses. This study aimed to evaluate the influence of growth regulators and the effect of light on calli induction from leaves disks of Eugenia involucrata. A bifactorial experiment (2x5) was conducted, in which the treatments consisted in the combinations of absence or presence of light during cultivation and five different uses of phytoregulators: NAA, 2,4-D, BAP and combinations of NAA and BAP, 2,4-D and BAP, all at 5 μM, in the nutritious medium MS. After 45 days of in vitro cultivation, it was observed that the absence of light during the cultivation period reduced phenolic oxidation, thus stimulated calogenesis, mainly in the presence of ANA and the combinations NAA + BAP and 2,4-D + BAP. The use of 2,4-D and BAP, on isolated way, did not favor calli formation in leaves disks of Eugenia involucrata.

ABSTRACT Physalis angulata L. is a plant with great fruit production potential, mainly in family farms, due to its versatility and valuable products such as jellies and juice concentrates. The aim of the present study is to evaluate the effect of two cytokines - i.e., plant growth regulators 6- benzylaminopurine (BAP) and kinetin (KIN) -, in association, or not, with auxin (2,4-dichlorophenoxyacetic acid - 2.4-D), on P. angulata multiplication in vitro. The experiment followed a completely randomized design, with eighteen treatments and five repetitions, based on factorial arrangement 2 x 5 x 2. Cytokinin sources were used at concentrations: 0, 2.5, 5.0, 7.5 and 10 mg L-1; in the presence (0.05 mg L-1) or absence of 2.4-D. Explants comprised nodal segments (approximately 1 cm) deriving from Physalis seed germination in vitro. Results indicate that the growth regulator KIN, at 5 mg L-1 concentration and in the absence of auxin 2.4-D, has potential to enable longer shoot length and larger number of internodes. However, the culture medium (MS) without plant growth regulators recorded higher biomass (fresh and dry weight) and increased root rate.

RESUMO A helmintosporiose está entre as principais doenças da cultura do milho. Realizou-se dois ensaios com os objetivos de avaliar a esporulação do fungo diferentes meios de cultura, métodos de inoculação e concentrações de inóculo para Exserohilum turcicum. Para a esporulação em diferentes meios de cultura, testou-se seis diferentes substratos: batata sacarose ágar (BSA), extrato de folha de milho (FM), potato dextrose ágar (PDA), suco V8 ágar (V8), lactose caseína hidrolisada ágar (LCHA) e meio semi-seletivo De Rossi e Reis (DRR) submetidos a dois regimes luminosos, fotoperíodo de 12 e escuro contínuo. E no segundo ensaio avaliou-se dois métodos de inoculação: a aspersão e a deposição do inóoculo no cartucho das plântulas, sendo testadas as concentrações de 5x103, 10x103, 15x103 20x103, 25x103 conídios/mL, e para o segundo foram depositados 0,5 mL na concentração de 20x103 conídios/mL nos cartuchos. Para ambos os métodos a inoculação foi feita no estádio V4 (quarta folha expandida, apresentando colar, lígula e aurículas visíveis), e mantidos em câmara úmida por 24 horas na temperatura de 25 0C. Quinze dias após a inoculação, avaliou-se a severidade estimada e a área da lesão. O delineamento experimental foi inteiramente casualizado com quatro repetições e os dados obtidos foram submetidos à análise de variância e de regressão. O maior número de conídios.cm-2 foi obtido no meio DRR, independente do regime luminoso. O método de aspersão mostrou-se eficaz nas concentrações de 15x103, 20x103 e 25x103 conídios/mL

ABSTRACT Helminthosporiosis is among the major corn diseases. Two experiments were carried out with the aim of evaluating fungal sporulation in different culture media, inoculation methods and inoculum concentrations for Exserohilum turcicum. For sporulation in different culture media, six different substrata were tested: potato sucrose agar (BSA), maize leaf extract (FM), potato dextrose agar (PDA), V8 juice agar (V8), lactose casein hydrolysate agar (LCHA) and semi-selective medium De Rossi and Reis (DRR) subjected to two light regimes, 12 hours photoperiod and continuous dark. In the second assay, two inoculation methods were evaluated: spray and deposition of the inoculum in the seedling cartridge, testing the concentrations of 5x103, 10x103, 15x103 20x103, 25x103 conidia / mL, and in the second one, 0.5 mL at the concentration of 20x103 conidia/mL were deposited in the cartridges. For both methods, inoculation was done in stage V4 (fourth expanded leaf, showing collar, ligule and visible auricles) and kept in a humid chamber for 24 hours at the temperature of 25 0C. Fifteen days after inoculation, the estimated severity and the lesion area were evaluated. The experimental design was completely randomized with four replicates, and data were subjected to analysis of variance and regression. The highest number of conidia.cm-2 was obtained in the DRR medium, independent of the light regime. The spray method was effective at the concentrations of 15x103, 20x103 and 25x103 conidia/mL.

RESUMO: A helmintosporiose e a ferrugem comum estão entre as principais doenças fúngicas que afetam a produção do milho. Os objetivos desse trabalho foram avaliar a suscetibilidade de dez híbridos de milho a helmintosporiose e a ferrugem comum e verificar a eficiência de fungicidas no controle de Exserohilum turcicum. No primeiro experimento utilizaram-se os híbridos Pioneer (30F53, P1630H, P2530), Monsanto (AG 8045, AG 9045), Dow AgroSciences (2A550, 2A106 e 2B587) e Syngenta (SYN7205 VIPTERA, SW 3949 TL), e no experimento de eficiência de fungicidas no controle de helmintosporiose, testou-se a eficiência dos fungicidas propiconazol, azoxistrobina, ciproconazol + azoxistrobina, protioconazol + trifloxistrobina, benzovindiflupir + azoxistrobina, ciproconazol + azoxistrobina + mancozebe, no híbrido Pioneer P1630H. Em ambos os experimentos avaliaram-se a severidade foliar das doenças (%), o rendimento e o peso de mil sementes. O delineamento experimental foi em blocos ao acaso com quatro repetições. Os híbridos SYN7205, P2530, SW 3949 TL, 2B587, AG 9045, 2A550, P1630H, 2A106 e AG 8025 apresentam as menores áreas abaixo da curva de progresso de severidade de ferrugem comum. Os híbridos AG9045, 30F53 e 2A550 apresentam as menores áreas abaixo da curva de progresso de helmintosporiose. Os híbridos AG8025, 2B587, P1630H, AG9045, 2A106 e 2A550 apresentam os maiores rendimentos. Os fungicidas protioconazol + trifloxistrobina apresentam a maior eficiência de controle químico de helmintosporiose e a menor AACPD.

ABSTRACT: Northern corn leaf blight (NCLB) and common rust are among the primary fungal diseases affecting maize production. This study aimed to evaluate the susceptibility of ten maize hybrids to NCLB and to common rust and to verify the efficiency of fungicides in the chemical control of Exserohilum turcicum. In the first experiment, hybrids Pioneer (30F53, P1630H, P2530), Monsanto (AG 8045, AG 9045), Dow AgroSciences (2A550, 2A106 and 2B587) and Syngenta (SYN7205 VIPTERA, SW 3949 TL) were used and in the experiment for effectiveness of fungicides in the control of NCLB. The efficiency of fungicides propiconazole, azoxystrobin, cyproconazole + azoxystrobin, prothioconazole + trifloxystrobin, benzovindiflupir + azoxystrobin, cyproconazole + azoxystrobin + mancozeb were tested in the Pioneer P1630H hybrid. In both experiments, the leaf disease severity (%), yield and the weight of one thousand seeds were evaluated. The experimental design was carried out in randomized blocks with four replicates. The hybrids SYN7205, P2530, SW 3949 TL, 2B587, AG 9045, 2A550, P1630H, 2A106 and AG 8025 showed the smallest areas under the common rust severity progress curve. Hybrids AG9045, 30F53, and 2A550 presented the smallest areas under the NCLB progress curve. Hybrids AG8025, 2B587, P1630H, AG9045, 2A106, 2A550, present the highest yields. The fungicides prothioconazole + trifloxystrobin present the highest chemical control efficiency for NCLB and the lowest area under the disease progress curve (AUDPC).

Resumo A mastite bovina está associada a uma resposta antibacteriana endógena mediada pela produção de espécies reativas. Contudo, o excesso de reações oxidativas pode desencadear apoptose celular agravando o quadro clínico dos animais. Neste contexto, o objetivo deste estudo foi avaliar a resposta redox no plasma de vacas leiteiras com e sem mastite submetidas ou não ao tratamento com antibioticoterapia. As vacas foram divididas em Grupo Controle (G1), vacas sem mastite; grupo G2, vacas com mastite sem tratamento com antimicrobianos; grupo G3, vacas com mastite tratadas com antibiótico. As amostras sanguíneas foram coletadas após a primeira ordenha da manhã. Foram analisados a existência de lipoperoxidação (LPO) e os níveis de proteínas carboniladas (PCs), de glutationa reduzida (GSH), de ácido ascórbico (ASA) e de ácido úrico (AU). Os animais do G3 apresentaram aumento na LPO e das PCs. Em todos os grupos, os níveis de GSH permaneceram inalterados. Os valores plasmáticos de ASA e de AU mostraram-se diminuídos nos animais dos grupos G2 e G3. Os resultados demonstraram que o tratamento com antimicrobianos parece agravar os danos oxidativos presentes na mastite bovina, reforçando a importância da busca por alternativas terapêuticas a fim de minimizar esse efeito.

Abstract Bovine mastitis is associated with an endogenous antibacterial response mediated by the production of reactive species. However, excess oxidative reactions can trigger cellular apoptosis, aggravating the clinical state of the animals. In this context, the objective of this study was to evaluate the plasma redox response of dairy cows with and without mastitis submitted or not to antibiotic therapy. The cows were divided into control group (G1), cows without mastitis; group G2, cows with mastitis without antimicrobial treatment; group G3, cows with mastitis treated with antibiotics. Blood samples were collected after the first milking of the morning. The existence of lipoperoxidation (LPO) and the levels of carbonylated proteins (CPs), reduced glutathione (GSH), ascorbic acid (ASA), and uric acid (UA) were analyzed. The G3 animals showed increase in LPO and CPs. In all groups GSH levels were unchanged. Plasma ASA and AU values were decreased in the G2 and G3 groups. The results demonstrated that antimicrobial treatment seems to aggravate the oxidative damages present in bovine mastitis, reinforcing the importance of the search for therapeutic alternatives in order to minimize this effect.

RESUMO Eugenia involucrata DC. (Myrtaceae) é uma espécie florestal com potencialidade econômica, para uso madeireiro, frutícola e ornamental. Este trabalho objetivou avaliar o efeito de Thidiazuron (TDZ) e Acido α-Naftaleno Acético (ANA) sobre a multiplicação in vitro de segmentos nodais de E. involucrata. Foi testada a ausência e a presença de ANA (a 0,5 µM) combinadas ao TDZ nas concentrações 0, 2, 4, 8, 16 ou 32 µM sobre algumas variáveis da multiplicação in vitro de E. involucrata. O uso de TDZ combinado a ANA (a 0,5 µM) favoreceu a emissão de brotações e de gemas nos explantes, especialmente a 32 µM. Concentrações intermediárias de TDZ também promoveram brotações, mas induziram à ocorrência de hiperidricidade nos explantes. É possível multiplicar e induzir segmentos nodais de E. involucrata à organogênese na presença de TDZ, preferencialmente combinado com ANA.

ABSTRACT Eugenia involucrata DC. (Myrtaceae), an economically important forest tree species, is prized for its timber and fruits, and is also an important ornamental plant. This study aimed to evaluate the effect of Thidiazuron (TDZ) and α-Naphthaleneacetic acetic acid (NAA) on in vitro multiplication of nodal segments of E. involucrata. We tested the effect of the absence and presence of NAA (0.5 µM), combined with TDZ at concentrations of 0, 2, 4, 8, 16, or 32 µM, on the in vitro multiplication of E. involucrata. The use of TDZ combined with NAA (0.5 µM) favored the formation of shoots and buds in the explants, especially at 32 µM TDZ concentration. Intermediate concentrations of TDZ also promoted shoot formation but induced hyperhydricity in the explants. It is possible to induce organogenesis leading to the multiplication of E. involucrata nodal segments using TDZ, preferably combined with NAA.

RESUMO Culturas de cobertura são fundamentais para a sustentabilidade do sistema plantio direto por garantir a cobertura do solo e por proporcionar benefícios para a cultura subsequente. O presente trabalho teve o objetivo de avaliar a produção de biomassa, o teor e acúmulo de nutrientes por plantas de cobertura de inverno. O delineamento experimental foi o de blocos casualizados, com seis tratamentos: nabo forrageiro, ervilhaca, aveia preta, ervilhaca + aveia preta, ervilhaca + nabo forrageiro e pousio, com quatro repetições. O cultivo solteiro de aveia preta, nabo forrageiro e o consórcio de aveia preta + ervilhaca e ervilhaca + nabo forrageiro apresentam maior produção de matéria seca. O consórcio ervilhaca + nabo forrageiro demonstra desempenho superior quanto à ciclagem dos nutrientes, com maiores acúmulos de N, P, K, Ca, Mg, S, Cu, Zn, Fe, Na e B.

ABSTRACT Cover crops are of fundamental importance for the sustainability of the no-tillage system, to ensure soil coverage and to provide benefits for the subsequent crop. The objective of this study was to evaluate the production of biomass and the content and accumulation of nutrients by winter cover crops. The experimental design used in the experiment was a randomized complete block with four replications and six treatments: oilseed radish, vetch, black oats, vetch + black oats, vetch + oilseed radish and fallow. Black oat, oilseed radish in single cultivation and black oat + vetch and vetch + oilseed radish intercroppings showed higher dry matter production. Vetch + oilseed radish intercropping demonstrates higher performance regarding cycling of nutrients, with higher accumulations of N, P, K, Ca, Mg, S, Cu, Zn, Fe, Na and B.

Neste trabalho, objetivou-se identificar os principais gêneros fúngicos associados a três lotes de sementes de Pinus taeda L.; avaliar a qualidade sanitária e fisiológica desses lotes, para utilizar como critério de seleção para a cultura de tecidos e analisar o estabelecimento in vitro de explantes de origem seminal. Foi possível discriminar os lotes quanto à qualidade sanitária e fisiológica, bem como estabelecer in vitro plantas de Pinus taeda, a partir de nós cotiledonares obtidos da germinação asséptica de sementes de um lote selecionado pela qualidade sanitária e fisiológica. Os meios nutritivos MS, ½ MS e WPM são igualmente adequados para esse fim. Para a análise sanitária, os gêneros fúngicos Fusarium, Penicillium e Trichoderma são os de maior sensibilidade. Para a avaliação fisiológica mostraram-se adequadas as variáveis: plântulas anormais, plântulas normais fortes, comprimento, massa fresca e massa seca de plântulas normais fortes. As análises mostraram-se favoráveis à escolha de lotes de sementes para o cultivo in vitro e todos os meios de cultura utilizados foram adequados ao estabelecimento da espécie em cultura de tecidos.

The aim of this work was to identify the fungi genera associated with three Pinus taeda L. seed lots and to assess the sanitary and physiological quality of these lots for use as selection criteria for tissue culture and evaluate the in vitro establishment of explants from seminal origin in different nutritive media. It was possible to discriminate the lots on the sanitary and physiological quality, as well as to establish in vitro plants of Pinus taeda from cotyledonary nodes obtained from aseptic seed germination of a selected lot by the sanitary and physiological quality higher. The nutritive media MS, ½ MS and WPM were equally suitable for this purpose. For the sanitary analysis the fungal genera Fusarium, Penicillium and Trichoderma were those of the highest sensitivity. For the physiological evaluation were important the variables: abnormal seedlings, strong normal seedlings; length, fresh and dry weight of strong normal seedlings. The analyzes were favorable to choose lots of seeds for in vitro culture and all culture media were adequate for the establishment of this species in tissue culture.

O presente trabalho objetivou avaliar o efeito de diferentes formas de inoculação, no meio nutritivo, de explantes foliares de Eugenia involucrata DC., uma espécie florestal nativa com diversas potencialidades econômicas. Foram avaliadas as posições abaxial, adaxial, com e sem cortes no limbo foliar. Foi utilizado o meio de cultura MS acrescido de 10 µM de ANA isolado ou das combinações, em µM, de 2,4-D e BAP: 5-5 e 5-10. A posição dos explantes afeta a calogênese e a organogênese em segmentos foliares de E. involucrata, sendo mais adequada a abaxial sem cortes na região do limbo. A associação dos reguladores de crescimento 2,4-D + BAP na concentração de 5-10 µM foi mais promissora para a obtenção de calos, especialmente os nodulares, putativos à embriogênese somática.

The aim of this research was to evaluate the effect of different forms of leaf explants inoculation in nutritive medium of Eugenia involucrata DC., an native forest species with diverse economic potentials. Inoculations were evaluated at abaxial and adaxial positions, with and without cuts on the leaf surface in the MS nutritive medium supplemented with 10 µM NAA or combination, in µM, of 2.4-D and BAP: 5-5 and 5-10. The explants position inoculation affects the callus induction and organogenesis in E. involucrata leaf segments, being the abaxial the most suitable position, without cuts in the leaf surface. The combination of growth regulators 2.4-D and BAP, at concentrations of 5-10( µM) was most promising of callus obtaining, especially nodular callus, putative at somatic embryogenesis.

No presente trabalho, objetivou-se comparar duas metodologias de desinfestação superficial de explantes isolados de ramos semilenhosos e herbáceos de Eugenia involucrata DC. (Myrtaceae), visando à obtenção de cultivos assépticos. O melhor controle da contaminação bacteriana nos segmentos nodais provenientes de ramos semilenhosos foi obtido pela imersão, durante 25 minutos, em hipoclorito de sódio a 1,5%. Entretanto, 39,35% dos explantes apresentaram colônias bacterianas e o excesso de contaminações inviabilizou os cultivos. Segmentos apicais caulinares e segmentos nodais oriundos de ramos herbáceos não diferiram entre si e apresentaram reduzidas contaminações fúngicas (13,75%) e bacterianas (0,41%), além de elevado estabelecimento (91,92%). Hipoclorito de sódio a 1,5%, nos tempos testados, não é eficiente em promover a desinfestação superficial de segmentos nodais que já possuam aspectos lenhosos. É possível a obtenção de culturas assépticas de E. involucrata pelo cultivo de segmentos apicais caulinares e nodais obtidos após a realização de poda, e desinfestados com o auxílio de bicloreto de mercúrio e de hipoclorito de sódio.

This study aimed to compare two methods of surface disinfestation of explants isolated from semi-hardwood and herbaceous branches of Eugenia involucrata DC. (Myrtaceae) to obtain aseptic cultures. The better control of bacterial contamination in nodal segments from semi-hardwood branches was obtained by immersion for 25 minutes in sodium hypochloride at 1.5%. However, 39.35% of explants showed bacterial colonies and excessive contamination made it impossible the cultures. Apical and nodal shoot segments derived from herbaceous branches did not differ and showed reduced fungal contamination (13.75%) and bacterial contamination (0.41%), and high in vitro establishment (91.92%). Sodium hypochlorite at 1.5% in the time tested is not efficient in promoting surface disinfestation of nodal segments that already present woody aspects. It is possible to obtain aseptic cultures of E. involucrata for growing shoot apical and nodal segments obtained after the pruning, and sterilized with the aid of mercuric chloride and sodium hypochlorite.