ABSTRACT: The present study evaluated the efficiency of a protocol for micropropagation of stem apexes and nodal segments of basil ‘Grecco a Palla’ in various concentrations of 6-benzylaminopurine (BAP) and 3-indole butyric acid (IBA). A completely randomized design was used with six treatments distributed in five replications. A medium without growth regulators favored the survival of Ocimumbasilicum stem apexes inoculated in vitro, and thereby promoted the sprouting of explants, whereas, for nodal segments, it was necessary to use regulators, and the concentration of 0.5 mg.L−1 BAP 0.0 mg.L−1 of IBA was more beneficial for the species.

RESUMO: O objetivo deste trabalho foi avaliar a eficiência de um protocolo de micropropagação de ápices caulinares e segmentos nodais da cultivar de manjericão (Ocimum basilicum L.) ‘Grecco a palla’ em diferentes concentrações de BAP (6-benzilaminopurina) e de AIB (ácido 3-indol butírico). Foi utilizado delineamento experimental inteiramente casualizado, com seis tratamentos distribuídos em cinco repetições. Para ápices caulinares, meio sem a adição de reguladores de crescimento favoreceu a sobrevivência de ápices caulinares de O. basilicum inoculados in vitro, promovendo a brotação dos explantes. Enquanto que para segmentos nodais houve necessidade do uso de reguladores, sendo que a concentração de 0,5 mg.L-1 de BAP e 0,0 mg.L-1 de AIB foi mais benéfica para a espécie.

Summary: Benzo(a)pyrene (BaP) is a highly distributed molecule in ecosystems and a component of products that are used and consumed regularly. Recent studies have shown this xenobiotic metabolized by organisms forming carcinogenic metabolites, as well as having genotoxic and teratogenic effects associated with infertility and endocrine disorders. Similarly, due to its dispersion and bioaccumulation, this molecule can severely damage various ecosystems. Therefore, the objective of this study is to conduct a systematic review to demonstrate the importance of BaP in biological systems and its biodegradation as an alternative to bioremediation.

Resumen: El benzo(a)pireno (BaP) es una molécula que se encuentra altamente distribuida en los ecosistemas, así como también forma parte de productos que se utilizan y consumen de forma recurrente. Estudios recientes demuestran que este xenobiótico es metabolizado por los organismos formando metabolitos carcinogénicos, así como también tiene efectos genotóxicos, teratogénicos y se encuentra asociado a la pérdida de fertilidad y trastornos endócrinos. De la misma manera, debido a su dispersión y bioacumulación puede dañar severamente diversos ecosistemas. El objetivo de la presente es realizar una revisión sistemática para evidenciar la importancia del BaP en los sistemas biológicos y su biodegradación como una alternativa de biorremediación.

Resumen Los reguladores de crecimiento facilitan la propagación y aumentan el rendimiento en la producción de plantas. La adición en diferentes cantidades determina una mayor efectividad en la regeneración celular. Por tanto, este estudio evaluó el efecto de varias dosis del GA3 (ácido giberélico) y de la BAP (bencilaminopurina) en la productividad de minijardines clonales de teca en San Carlos, Costa Rica. Se estableció un ensayo con diseño factorial (2x4). Como factor (A) se utilizó al GA3 y la BAP, mientras que como factor (B) las dosis 0, 5, 10 y 20 mgl-1. El análisis de varianza y pruebas de comparación mostraron que el uso del GA3 aumentó significativamente la producción y longitud de brotes. Y, el BAP no presentó efectos significativos en la producción. La aplicación de 10 y 20 mgl-1 de GA3 aumentó la producción de brotes por planta madre de 1,02 a 1,47 y 1,50 aumentando la producción en un 44 y 47 % respectivamente, en cosecha quincenal ordinaria, y 169 hasta 172 brotes por metro cuadrado correspondiente a un 38 y 33 %. Al aplicar 5 mgl-1 hasta 20 mgl-1 de GA3 se obtuvo brotes desde 4,19 a 4,44 cm de longitud. En la tasa de enraizamiento, las diferencias se presentaron en el GA3 que demostró ser superior al BAP en un 49% para el enraizamiento diario medio, con una velocidad de 1,30 brotes por día. En conclusión, aplicar 10 mgl-1 de GA3 es suficiente para aumentar el rendimiento en la productividad de minijardines clonales de teca.

Abstract Growth regulators facilitate propagation and increase yield in plant production. Adding different amounts of regulators cause greater effectiveness in cell regeneration. Therefore, this study evaluated the effect of different doses of GA3 (gibberellic acid) and BAP (benzylaminopurine) on the productivity of clonal teak mini gardens in San Carlos, Costa Rica. A trial with a factorial design (2x4) was established. GA3 and BAP were used as factor (A), while doses of 0, 5, 10, and 20 mgl-1 were used as factor (B). The analysis of variance and comparison tests showed that the use of GA3 significantly increased shoot production and shoot length, while BAP had no significant effect on production. The application of 10 and 20 mgl-1 of GA3 increased shoot production per mother plant from 1.02 to 1.47 and 1.50 increasing the production by 44 and 47 % respectively, in ordinary biweekly harvest, and 169 to 172 shoots per square meter corresponding to 38 and 33 %. When 5 mgl-1 to 20 mgl-1 of GA3 were applied, shoots from 4.19 to 4.44 cm in length were obtained. In the rooting rate, the differences were presented in GA3 which proved to be superior to BAP by 49% for the average daily rooting, with a rate of 1.30 shoots per day. In conclusion, applying 10 mgl-1 of GA3 is sufficient to increase the productivity performance of clonal teak mini gardens.

Resumen Beaucarnea hookeri, es una especie endémica de México y está catalogada como amenazada en la NOM-059-SEMARNAT-2010. Con la finalidad de micropropagar esta especie, se estableció un experimento en el Campus Montecillo, Colegio de Posgraduados en 2022, donde se evaluó la respuesta de los brotes durante la multiplicación in vitro con diferentes concentraciones de bencilaminopurina (BAP) y su capacidad de enraizamiento ex vitro durante su aclimatización. Se estableció un experimento con tres subcultivos subsecuentes (SC3, SC4, SC4-1), en SC3 se utilizaron brotes generados con 0.5 mg L-1 de BAP (SC2), en SC4 brotes sanos generados del SC3 y SC4-1 con brotes del SC3, pero, con hiperhidratación inicial (HHI). En el SC3 se evaluaron 0.5, 1, 1.5, 2, 2.5 mg L-1 de BAP. En el SC4 0 y 0.5 mg L-1 BAP y en SC4-1 concentraciones de 0, 0.5 y 1 mg L-1 de BAP. Durante la aclimatización se evaluaron cuatro tratamientos de Radix® 10 000 (0, 1 000, 2 000 y 4 000 mg kg-1) y se utilizaron brotes del SC2. Durante la multiplicación se registró el número de brotes (NB) y el SC3 generó 6.35 brotes con la concentración 1.5 mg L-1 BAP, con presencia de HHI. En el SC4 se obtuvo 9.7 brotes en promedio y en SC4.1, 5.3 brotes, ambos subcultivos con 0.5 mg L-1 de BAP. Además, en el SC4-1 hubo recuperación de HHI. En el enraizamiento no existieron diferencias significativas entre los tratamientos y el testigo a 80 días del trasplante generó 73.3% de brotes con raíz (SBR). Únicamente los brotes del tratamiento testigo en multiplicación presentaron raíces lo que permite obtener plantas completas en 30 días.

Abstract Beaucarnea hookeri is a species endemic to Mexico and is listed as threatened in NOM-059-SEMARNAT-2010. In order to micropropagate this species, an experiment was established at the Montecillo Campus, College of Postgraduates in 2022, where the response of the shoots during in vitro multiplication with different concentrations of benzylaminopurine (BAP) and their capacity for ex-vitro rooting during acclimatization were evaluated. An experiment was established with three subsequent subcultures (SC3, SC4, SC4-1); in SC3, shoots generated with 0.5 mg L-1 BAP (SC2) were used; in SC4, healthy shoots generated from SC3; and SC4-1 with shoots from SC3 but with initial hyperhydration (IHH). In SC3, 0.5, 1, 1.5, 2, and 2.5 mg L-1 BAP were evaluated. In SC4, 0 and 0.5 mg L-1 BAP and in SC4-1, concentrations of 0, 0.5, and 1 mg L-1 BAP. During acclimatization, four treatments of Radix® 10 000 (0, 1 000, 2 000, and 4 000 mg kg-1) were evaluated, and shoots from SC2 were used. During multiplication, the number of shoots (NS) was recorded, and SC3 generated 6.35 shoots with the concentration of 1.5 mg L-1 BAP, with the presence of IHH. On average, 9.7 shoots were obtained in SC4, and 5.3 shoots in SC4-1, both subcultures with 0.5 mg L-1 BAP. In addition, there was a recovery of IHH in SC4-1. In rooting, there were no significant differences between treatments, and the control generated 73.3% of shoots with roots (SSR) 80 days after transplantation. Only the shoots of the control treatment in multiplication presented roots, which allowed complete plants to be obtained in 30 days.

Resumen La eficiencia en la regeneración de frambuesa, a partir de esplantes de hojas, se ve limitada debido a diversos factores, entre que los que destacan la edad del explante y el genotipo. El objetivo de esta investigación fue determinar el efecto de los reguladores de crecimiento sobre la oxidación y la regeneración in vitro a partir de explantes de hojas de cinco genotipos de frambuesa, el año del estudio fue en 2021. Se probaron dosis y combinaciones de auxinas y citocininas para inducir organogénesis directa en explantes foliares de los genotipos de frambuesa; ‘C-6’, ‘Joan J.’, ‘A-1’, ‘UM-702’ y ‘Heritage’. Los resultados mostraron que el regulador bencilaminopurina (BAP) disminuyó la oxidación en los genotipos ‘C-6’, ‘Joan J.’, ‘A-1’ y ‘Heritage’ en 36, 48, 60 y 68% respectivamente, los que se suplementaron con cinetina tuvieron una reducción de la oxidación en el genotipo ‘C-6’ (56%), cuando se adicionó tidiazuron (TDZ) la oxidación disminuyó en los genotipos evaluados en 72, 64, 72, 84 y 68% respectivamente. La mayor regeneración (número de brotes/explate) fue con BAP (0.5 mg L-1) y TDZ (0.2 mg L-1) + ácidoindolbutírico (AIB) (0.1 mg L-1) para el genotipo ‘C-6’, y TDZ (0.2 mg L-1) + AIB (0.1 mg L-1) para ‘Joan J.’ y ‘Heritage’. En ‘A-1’y ‘UMC-702’ se sugiere el uso de TDZ (0.2 mg L-1) solo. Se concluye que el uso de reguladores de crecimiento, solos o combinanados, disminuyen la oxidación en los explantes de hojas, y aumentan la sobrevivencia y regeneración de brotes en todos los genotipos evaluados.

Abstract The efficiency in raspberry regeneration, from leaf explants, is limited due to several factors, among which the age of the explant and the genotype stand out. The aim of this research was to determine the effect of growth regulators on oxidation and in vitro regeneration from leaf explants of five raspberry genotypes in 2021. Doses and combinations of auxins and cytokinins were tested to induce direct organogenesis in leaf explants of raspberry genotypes; ‘C-6’, ‘Joan J.’, ‘A-1’, ‘UM-702’ and ‘Heritage’. The results showed that the regulator benzylaminopurine (BAP) decreased oxidation in genotypes ‘C-6’, ‘Joan J.’, ‘A-1’ and ‘Heritage’ by 36, 48, 60 and 68%, respectively, those that were supplemented with kinetin had a reduction in oxidation in the genotype ‘C-6’ (56%), when thidiazuron (TDZ) was added, oxidation decreased in the genotypes evaluated by 72, 64, 72, 84 and 68%, respectively. The greatest regeneration (number of shoots/explant) was with BAP (0.5 mg L-1) and TDZ (0.2 mg L-1) + indole butyric acid (IBA) (0.1 mg L-1) for the genotype ‘C-6’, and TDZ (0.2 mg L-1) + IBA (0.1 mg L-1) for ‘Joan J.’ and ‘Heritage’. In ‘A-1’ and ‘UMC-702’, the use of TDZ (0.2 mg L-1) alone is suggested. It is concluded that the use of growth regulators, alone or combined, decreases oxidation in leaf explants, and increases the survival and regeneration of shoots in all genotypes evaluated.

Resumen La producción de piña (Ananas comosus L.) por métodos convencionales está limitada principalmente por la falta de disponibilidad de retoños de alto rendimiento. Sin embargo, se ha demostrado que por medio de metodologías de propagación in vitro como la embriogénesis somática y organogénesis, es posible obtener plantas de alto rendimiento de una manera más eficiente y controlable. El objetivo de este estudio consistió en generar un protocolo eficiente de micropropagación de piña criolla (Ananas comosus L.) para la multiplicación y conservación in vitro de esta especie, el estudio se llevó a cabo en 2021. Se evaluó la respuesta morfogénica de la piña criolla a partir de diferentes explantes (meristemo apical y hoja), cultivados en medio de cultivo Murashige y Skoog (MS) suplementado con diversos reguladores de crecimiento: ácido naftalenacético (ANA) (0.5, 1 y 1.5 mg L-1), 6-bencilaminopurina (BAP) (1, 2 y 3 mg L-1) y ácido 2,4-diclorofenoxiacético (2,4-D) (1, 2 y 4.5 mg L-1), así como un tratamiento control libre de reguladores. Los resultados mostraron que de los explantes evaluados la mejor respuesta se observó en el meristemo apical, en el cuales se obtuvo la formación de brotes adventicios a los 60 días del tratamiento de inducción, cuando el medio de cultivo fue suplementado con BAP a una concentración de 2 mg L-1 obteniéndose ocho brotes/explante. El protocolo desarrollado es un estudio clave para la propagación masiva de piña criolla.

Abstract The production of pineapple (Ananas comosus L.) by conventional methods is limited mainly by the lack of availability of high-yielding suckers. Nevertheless, it has been shown that, through in vitro propagation methodologies such as somatic embryogenesis and organogenesis, it is possible to obtain high-yielding plants in a more efficient and controllable way. The objective of this study was to generate an efficient protocol of micropropagation of landrace pineapple (Ananas comosus L.) for the in vitro multiplication and conservation of this species, the study was carried out in 2021. The morphogenic response of the landrace pineapple was evaluated based on different explants (apical meristem and leaf), grown in Murashige and Skoog (MS) culture medium supplemented with various growth regulators: naphthaleneacetic acid (NAA) (0.5, 1 and 1.5 mg L-1), 6-benzylaminopurine (BAP) (1, 2 and 3 mg L-1) and 2,4-dichlorophenoxyacetic acid (2,4-D) (1, 2 and 4.5 mg L-1), as well as a regulator-free control treatment. The results showed that, of the explants evaluated, the best response was observed in the apical meristem, in which the formation of adventitious shoots was obtained 60 days after induction treatment, when the culture medium was supplemented with BAP at a concentration of 2 mg L-1, obtaining eight shoots/explant. The protocol developed is a key study for the mass propagation of landrace pineapple.

Resumen Antecedentes: Agave potatorum es una especie endémica importante ecológica, cultural y económicamente. Poco se cultiva y sus poblaciones naturales están desapareciendo, por lo que una alternativa es la propagación por cultivo de tejidos vegetales. Preguntas: ¿Es posible regenerar nuevos individuos partiendo de estructuras somáticas? ¿Qué explante regenera más plántulas? ¿Qué combinación de reguladores del crecimiento vegetal estimula una mayor formación de brotes? Especie estudiada: Agave potatorum, semillas de Oaxaca, México. Lugar de estudio y fechas: Jardín Botánico, Instituto de Biología, UNAM, Ciudad de México, México. Desde 2020. Métodos: Semillas se desinfectaron y germinaron in vitro y ex vitro. Se cultivaron in vitro explantes de cotiledones, tallos y hojas en medio MS modificado, un mes con BAP (0-2 mg/L) combinado con 2,4-D (0-0.5 mg/L), posteriormente en MS sin reguladores del crecimiento vegetal. Las plantas obtenidas con tres o más raíces se sometieron a un proceso de aclimatización. Resultados: A dos meses de iniciados los cultivos las semillas germinaron in vitro (56.04 %) y ex vitro (31.87 %). Después de 10 meses del período de inducción, se obtuvieron 228 brotes y plántulas, 206 procedían de los tratamientos BAP 1.5-2 mg/L con 2,4-D 0.5 mg/L, con 8.1-12.5 brotes/explante de tallo y hoja. Más del 70 % de las plantas sobrevivieron en invernadero luego de dos meses. Conclusiones: Esta investigación puede contribuir a la conservación de la especie, enfrentar los efectos del cambio climático, la conservación de servicios ecosistémicos y potenciar la economía mediante un aprovechamiento sustentable de ésta y otras especies amenazadas.

Abstract Background: Agave potatorum is an endemic species of ecological, cultural and economic importance. Despite its importance and its overexploited status, it is barely cultivated and its natural populations have been disappearing, so an alternative is propagation by plant tissue culture. Questions: Is it possible to regenerate new individuals from somatic structures? From which explant do more plantlets regenerate? What combination of plant growth regulators stimulates more bud formation? Species studied: Agave potatorum, seeds from Oaxaca, Mexico Study site and dates: Botanical Garden, Institute of Biology, UNAM, Mexico City, Mexico. Since 2020 Methods: The explant culture of cotyledons, stems and leaves sections in modified MS medium was explored, one month with BAP (0-2 mg/L) combined with 2,4-D (0-0.5 mg/L). Subsequently in MS without plant growth regulators. The obtained plants with 3 or more roots underwent an acclimatization process. Results: The seeds' germination was achieved and at two months, the in vitro (56.04 %) and ex vitro (31.87 %) germination were obtained. At 10 months after the induction period, the total number of shoots and plantlets of all treatments was 228, most of them (206) were with BAP 1.5-2 mg/L with 2,4-D 0.5 mg/L promoted the regeneration of 8.1-12.5 shoots/explant of stem and leaf. More than 70 % of the plants survived in greenhouse after two months of culture. Conclusions: This investigation can contribute to the conservation of Agave potatorum, address climate change, conserve ecosystemic services, and strengthen the economy by using this and other endangered species sustainably.

ABSTRACT Melissa officinalis L., popularly known as lemon balm, is an aromatic plant widely used in medicine, cosmetics, and pharmaceutical industries for its essential oil rich in phenylpropanoids, terpenes, and phenolics. This study aimed to assess the effect of growth regulators on the development and physiological and biochemical metabolism of M. officinalis cultured in vitro. Seeds were inoculated in Murashige and Skoog medium and added with the regulators 6-benzylaminopurine (BAP) and 1-naphthaleneacetic acid (NAA) according to six different treatments. After 90 days of culture, plants were evaluated for growth and biochemical and physiological parameters (flavonoids, anthocyanins, and chlorophyll). The balance between regulators interfered with plant growth, which increased in the presence of 0.2 mg L-1 BAP. In this treatment, the plants had greater growth with more leaves, and the biomass production of shoots and roots was higher than the control. Growth regulators did not influence nitrogen assimilation or flavonoid production; however, total chlorophyll and anthocyanin indexes were enhanced by treatment with BAP at concentrations ranging from 0.2 to 0.5 mg L-1. Auxin treatment did not improve root production or growth but favored callus formation when combined with 0.5–3.0 mg L-1 BAP. The results indicate that high BAP concentrations (above 1.0 mg L-1) should not be used in in vitro production of lemon balm.

RESUMO A espécie Melissa officinalis L. conhecida como erva cidreira é uma planta aromática muito utilizada na medicina, indústria de cosméticos e farmacêutica, em função do seu óleo essencial rico em fenilpropanóides, terpenos e fenólicos. Objetivouse com esta pesquisa avaliar a ação dos reguladores de crescimento sobre o crescimento, processos fisiológicos e bioquímicos de plantas de M. officinalis cultivadas in vitro. Sementes foram inoculadas em meio de cultura Murashige e Skoog com os reguladores benzilaminopurina - BAP e ácido 1-naftalenoacético - ANA em seis diferentes tratamentos. Ao final de 90 dias foram avaliados: crescimento da planta, índices bioquímicos e fisiológicos sendo flavonoides, antocianinas e clorofila. O balanço entre os reguladores interferiu no crescimento da melissa que foi incrementado em 0,2 mg L-1 de BAP. Neste tratamento, as plantas tiveram maior crescimento com mais folhas como também a produção de biomassa das brotações e das raízes foi maior comparada ao controle. Os reguladores de crescimento não influenciaram na assimilação de nitrogênio e na produção de flavonoides, no entanto as clorofilas totais e as antocianinas foram incrementadas com a adição de BAP na faixa de 0,2 a 0,5 mg L-1. A adição de auxinas não melhorou aspectos de produção e crescimento da raiz, mas favoreceu a formação de calos quando foi combinada com o BAP a 0,5 e 3,0 mg L-1. Portanto, concentrações acima 1,0 mg L-1 não devem ser utilizadas no cultivo in vitro da melissa.

ABSTRACT Velloziaceae is one of the main families in the floristic composition of the Campos Rupestres Montane Savanna ecoregion of the Chapada Diamantina Highland, Bahia, Brazil, and has species with significant ornamental potential and resistance to climate changes. The species Vellozia seubertiana stands out for its beautiful flowers and stems covered by leaf sheaths that ensure protection when in contact with fire. However, there is no information on its propagation, conservation, and physiology, which justifies this study. The objective of this work was to establish a micropropagation protocol for V. seubertiana. Seeds were disinfected and inoculated in Murashige and Skoog culture medium (MS) with half salt concentration (MS½) for in vitro establishment. Plantlets established in vitro were used to induce sprouting in MS½ supplemented with 6-benzylaminopurine (BAP; 0.00, 4.44, 8.88, and 17.76 µM) and 1-naphthaleneacetic acid (NAA; 0.00 and 2.22 µM). The shoots obtained were inoculated in MS½ containing activated charcoal (0.0 and 1.0 g L−¹) and indole-3-butyric acid (IBA; 0.00 and 2.22 µM) for rooting. The rooted plantlets were acclimated under greenhouse conditions. A mean of 5.7 shoots were generated through organogenesis in medium containing 8.75 µM of BAP and 2.22 µM of NAA. The use of activated charcoal resulted in the highest means for aerial part and root lengths in the in vivo rooting phase. Acclimated plants reached 75% survival at 60 days after transplanting to ex vitro conditions. The results indicate that micropropagation is a promising technique for the production of V. seubertiana seedlings.

RESUMO Velloziaceae é uma das principais famílias da composição florística dos campos rupestres da Chapada Diamantina e possui espécies com significativo potencial ornamental e resistência a mudanças climáticas. A espécie Vellozia seubertiana se destaca pela beleza das flores e por possuir caules cobertos por bainhas foliares que asseguram proteção quando em contato com o fogo. Não há relatos sobre a sua propagação, conservação e entendimento da sua fisiologia, o que justifica a realização deste estudo. Este trabalho teve como objetivo estabelecer um protocolo de micropropagação da espécie V. seubertiana. Para o estabelecimento in vitro, as sementes foram desinfestadas e inoculadas em meio MS com metade das concentrações salinas (MS ½). Microplantas estabelecidas in vitro foram utilizadas para a indução de brotos em meio MS ½ suplementado com BAP (0,00; 4,44; 8,88 e 17,76 µM) e ANA (0,00 e 2,22 µM). Os brotos obtidos foram inoculados em meio MS ½ contendo carvão ativado (0,0 e 1,0 g L-¹) e AIB (0,00 e 2,22 µM) para enraizamento. Microplantas enraizadas foram aclimatizadas em casa de vegetação. Obteve-se uma média de 5,7 brotos via organogênese em meio contendo 8,75 µM de BAP e 2,22 µM de ANA. Na fase de enraizamento, a presença do carvão ativado proporcionou as maiores médias para comprimento de parte aérea e comprimento de raiz. As plantas aclimatizadas atingiram 75% de sobrevivência após 60 dias da transferência para a condição ex vitro. Conclui-se que a micropropagação é uma técnica promissora para a produção de mudas de V. seubertiana.

Abstract Green and variegated Benjamin fig (Ficus benjamina) often suffer from root restriction when grown in pots. While exogenous cytokinin applications have proven effective in reversing this stress, the possibility that exogenous auxins, either alone or in combination with cytokinin, may also be helpful has received little attention. In this work, we analyse the response of green and variegated Ficus benjamina rooted cuttings growing in small pots to exogenous supply of auxin and cytokinin at different concentrations, either in single or combined applications. Our results show that both benzyl aminopurine (BAP) and indole acetic acid (IAA), at the highest concentration tested (100 mg L-1) increased leaf development and plant biomass accumulation in green and variegated Ficus genotypes. However, exogenous IAA and BAP appeared to elicit differential plant morpho-physiological responses. While BAP tended to enhance leaf appearance more than IAA did, the latter promoted leaf expansion in a steadier manner than BAP, thus resulting in plants with less, but larger, leaves than those treated with cytokinin. Despite these differences in plant architecture, regression analysis suggests that hormonal-induced growth promotion was solely attributable to enhanced carbon assimilation. Rather unexpectedly, IAA promoted net assimilation and photosynthesis rates at least as effectively as cytokinin. Possible mechanisms involved in growth and development promotion by exogenous application of both hormones are discussed. Auxin treatment may help overcome root restriction in Ficus as effectively as cytokinin in terms of growth promotion, although differences in plant architecture may arise as compared with plants sprayed with the latter hormone.

Resumo Ficus Benjamina (Ficus benjamina) verde e variegado geralmente sofre de restrição no crescimento das raízes quando cultivado em vasos. Embora as aplicações de citocinina exógena tenham se mostrado eficazes na reversão desse estresse, a possibilidade de que auxinas exógenas, sozinhas ou em combinação com citocinina, também possam ser benéficas tem recebido pouca atenção. Neste trabalho, foi analisada a resposta de estacas enraizadas de Ficus benjamina verdes e variegadas cultivadas em pequenos vasos, em relação ao fornecimento exógeno de auxina e citocinina em diferentes concentrações, em aplicações únicas ou combinadas. Nossos resultados mostram que tanto a benzilaminopurina (BAP) quanto o ácido indol-acético (IAA), na maior concentração testada (100 mg L-1), aumentaram o desenvolvimento foliar e o acúmulo de biomassa vegetal nos genótipos de Ficus verde e variegado. No entanto, AIA e BAP exógenos parecem provocar respostas morfofisiológicas diferenciadas nas plantas. O uso de BAP teve a tendência de melhorar a aparência das folhas mais do que AIA, sendo que este promoveu a expansão foliar de maneira mais estável do que o BAP, resultando em plantas com menos folhas, porém maiores, do que as tratadas com citocinina. Apesar dessas diferenças na arquitetura da planta, a análise de regressão sugere que a promoção do crescimento induzida por hormônios foi atribuída exclusivamente ao aumento da assimilação de carbono. De forma bastante inesperada, o AIA promoveu assimilação líquida e taxas de fotossíntese pelo menos tão efetivamente quanto a citocinina. Possíveis mecanismos envolvidos na promoção do crescimento e desenvolvimento pela aplicação exógena de ambos os hormônios são discutidos. O tratamento com auxina pode ajudar a superar a restrição radicular em Ficus de forma tão eficaz quanto a citocinina em termos de promoção de crescimento, embora possam surgir diferenças na arquitetura da planta em comparação com plantas pulverizadas com o último hormônio.

ABSTRACT Cut flowers are known for their beauty and variety of colors and shapes. However, they quickly lose their commercial value after harvest due to the intensity of physiological processes that result in senescence. This work aimed to evaluate the effects of bioregulators on the postharvest longevity of lisianthus flowers (Eustoma grandiflorum cv. Flare Deep Rose) by applying a pulsing solution for 24 hours. The treatments consisted of 70 µM of 6-benzylaminopurine (BAP); 5 µM of gibberellic acid (GA3); 10 µM of abscisic acid (ABA); and deionized water as control. Turgidity, floral development, total and reducing sugar contents, respiration rate, colorimetry, anthocyanin contents, phenolic compound contents, and phenylalanine ammonia-lyase (PAL) enzyme activity were evaluated. BAP resulted in higher PAL enzyme activity and greater accumulation of anthocyanins when compared to the other treatments. The treatment GA3 resulted in the highest increase in respiration rate during storage, causing a larger number of inflorescences with wilting and senescence symptoms, reducing postharvest quality. The treatment ABA resulted in greater turgidity and floral opening, delayed senescence, and maintained respiration rate due to the greater total sugar contents on the fourth and 12th days. The application of ABA contributes to the maintenance of inflorescence quality for lisianthus at postharvest, but it reduces anthocyanin contents, providing petals with lighter colors.

Abstract It has been suggested that the response of the specialty cut flower Limonium sinuatum to different abiotic stress situations related to the plug tray cell size during nursery could be associated with the synthesis and translocation of endogenous cytokinins produced in the root tips. To validate this hypothesis, the aim of this work was to evaluate the participation of cytokinins in the process of biomass accumulation in L. sinuatum plants through foliar spraying with a synthetic cytokinin (benzyl aminopurine, BAP) and an inhibitor of the synthesis of endogenous cytokinins (dopamine). Our results indicated that spraying L. sinuatum plants with BAP increased leaf area initiation and expansion, biomass accumulation through increased plant photosynthetic capacity, and differential partitioning towards the shoot apical meristem by a positive feedback mechanism that has a threshold of optimal response close to 100 mg L-1 BAP. Dopamine spraying appeared to affect the synthesis of endogenous cytokinins, reducing the previously mentioned responses. Responses were dose-dependent, with an optimum of 100 mg L-1 BAP and 200 mg L-1 dopamine. Our results allow concluding that the level of endogenous cytokinins during the abiotic stress such as root restriction during nursery is a determining variable of the biomass accumulation process in this species.

Resumo A bibliografia aponta que existe resposta de Limonium sinuatum a diferentes situações de estresse abiótico relacionadas ao tamanho das células durante o cultivo no viveiro e que este pode estar associada à síntese e translocação de citocininas. Para testar essa hipótese, o objetivo deste trabalho foi avaliar a participação das citocininas no processo de acúmulo de biomassa em plantas de L. sinuatum por meio de pulverização foliar com uma citocinina sintética (benzilaminopurina, BAP) e um inibidor da síntese de citocininas endógenas (dopamina). Nossos resultados indicaram que a pulverização com BAP aumentou a iniciação e expansão da área foliar, acúmulo de biomassa através do aumento da capacidade fotossintética da planta e partição diferencial em direção ao meristema apical da parte aérea com um ponto de máxima próximo a 100 mg L-1 BAP. A pulverização de dopamina pareceu afetar a síntese de citocininas endógenas, reduzindo as respostas mencionadas anteriormente. As respostas foram dose-dependentes, com um ótimo de 100 mg L-1 de BAP e 200 mg L-1 de dopamina. Nossos resultados permitem concluir que o nível de citocininas endógenas durante o estresse abiótico como a restrição radicular durante a fase de viveiro é uma variável determinante do processo de acúmulo de biomassa nesta espécie.

RESUMO Reclaimed Asphalt Pavement (RAP) has a variety of organic and inorganic compounds that can interact with the environment and promote deleterious effects on human health. This study investigated the potential toxicity of RAP through metal determination, polycyclic aromatic hydrocarbon (PAH) analysis and acute toxicity tests with Daphnia magna. Leached and solubilized extracts of RAP samples and a freshly produced asphalt sample were compared. Regarding metals, Mn was above the Brazilian acceptance criteria in the solubilized extract. The samples showed concentrations of Cd, Cr, and Pb, which are on the list of substances that render waste hazardous. For PAH, two samples of leachate had BaP concentration above the maximum value allowed and the other samples had BaP values close to the established limit. In addition, the samples still presented concentrations of BaA, BbF, IcdP, and Chr. For the acute toxicity tests, two solubilized samples indicated acute toxicity to Daphnia magna. The results indicated that the method of preparing the leached and the solubilized extract influenced the values of metals and acute toxicity. Two samples of RAP could be classified as hazardous waste, pointing out that these materials have the potential to leach hazardous substances to the environment. Therefore, the disposal of this type of waste should be carefully evaluated, as its composition contains substances that may degrade the environment and cause toxicological effects on living organisms.

ABSTRACT Pavimentos asfálticos fresados (PAF) apresentam uma variedade de compostos orgânicos e inorgânicos que podem interagir com o meio ambiente e promover efeitos deletérios à saúde humana. Este estudo investigou o potencial de toxicidade dos PAF por meio da determinação de metais, hidrocarbonetos policíclicos aromáticos (HPA) e testes de toxicidade aguda com Daphnia magna. Foram comparados extratos lixiviados e solubilizados de amostras de PAF e de resíduo asfáltico fresco. As análises de Mn apresentaram concentrações acima do critério de aceitação normativo brasileiro para os extratos solubilizados. As amostras resultaram em concentrações de Cd, Cr e Pb, que estão na lista de substâncias que conferem periculosidade aos resíduos. Em relação aos HPA, duas amostras de lixiviado apresentaram concentração de BaP acima do valor máximo permitido e as demais amostras apresentaram valores de BaP próximos ao limite estabelecido. Ademais, foram identificadas nas amostras concentrações de BaA, BbF, IcdP e Chr. Para os ensaios de toxicidade aguda, duas amostras solubilizadas indicaram toxicidade aguda para Daphnia magna. Os resultados indicaram que o método de preparo dos lixiviados e do extrato solubilizado influenciaram os valores de metais e a toxicidade aguda. Duas amostras de PAF foram classificadas como resíduos perigosos, sinalizando que tais materiais apresentam potencial para lixiviar substâncias perigosas ao ambiente. Portanto, a disposição em solo desse tipo de resíduo deve ser criteriosa, uma vez que sua composição contém substâncias que podem impactar o meio ambiente e causar efeitos toxicológicos em organismos vivos.

Abstract Plants raised in small cell trays are often subjected to root growth restrictions. Root tips are a source of cytokinin, and insufficient biosynthesis and transport of this hormone to the aerial part severely impairs shoot development. Exogenous supply of cytokinin to the foliage has been shown to effectively counteract these effects in several horticultural crops, but the physiological processes involved are still unclear. The aim of this work was to study the effect of spraying the cytokinin 6-benzylaminopurine (BAP) on growth and development of plug lettuce seedlings focusing on the morpho-physiological mechanisms involved in plant response. Two experiments were conducted in a greenhouse. Lettuce (Lactuca sativa L. Crimor INTA) seedlings were grown for 35 days in 128-, 200- and 288-cells trays (17.37, 13.90 and 6.18 cm3·cell-1 respectively), after which they were sprayed with BAP (6-benzylaminopurine) solutions (0, 5, 50 or 100 mg·L-1) either immediately before transplant, or 7 days after transplant. Seedlings were transplanted into larger (3,000 cm3) pots in which they grew for further 60 days. Decreasing plug cell volume resulted in a steep decrease in plant net assimilation rate and leaf net photosynthetic rate, but the impact on the relative growth rate was somewhat lower due to an increased leaf area ratio. BAP sprays increased plant biomass accumulation and enhanced the development of photosynthetic area, in parallel with a strong promotion of carbon assimilation, and these effects were more remarkable in plants raised in smaller plugs, and when hormone was supplied at the pre-transplant stage.

Resumen Las plantas cultivadas en charolas de germinación de celdas pequeñas frecuentemente son sometidas a restricciones radicales. Las puntas de las raíces son una fuente de citoquinina, y la biosíntesis y el transporte de esta hormona a la parte aérea restringe severamente el desarrollo de los brotes. La aplicación de citoquinina al follaje ha demostrado ser efectiva para contrarrestar los efectos negativos en muchos cultivos hortícolas, pero los procesos fisiológicos involucrados permanecen inciertos. El objetivo de este trabajo fue evaluar el efecto de asperjar citoquinina 6-bencilaminopurina (BAP) sobre el crecimiento y desarrollo de plántulas de lechuga, concentrándose en los mecanismos morfo-fisiológicos relacionados con la respuesta de la planta. Se realizaron dos experimentos en un invernadero; para ello, se cultivaron plántulas de lechuga (Lactuca sativa L. Crimor INTA) durante 35 días en charolas de germinación de 128, 200 y 288 celdas (17.37, 13.90 y 6.18 cm3·celda-1, respectivamente), después se asperjaron con soluciones de BAP (0, 5, 50 o 100 mg·L-1), antes del trasplante o 7 días después de este. Las plántulas se trasplantaron en macetas más grandes (3,000 cm3), donde crecieron por 60 días. La disminución de la celda redujo la tasa de asimilación neta de la planta y la tasa fotosintética neta, pero el impacto en la tasa de crecimiento relativo fue un poco menor debido al incremento de la relación del área foliar. Las aspersiones de BAP incrementaron la acumulación de biomasas y ampliaron el desarrollo del área fotosintética; asimismo, se promovió la asimilación de carbono. Estos efectos fueron destacables en las plantas cultivadas en celdas menores, y cuando la hormona fue suministrada en la etapa de pre-trasplante.

Human urine constitutes 1% of domestic wastewater and can be used to recover nitrogen and phosphorus when collected separately at source. Sustainable nutrient (nitrogen, phosphate, potassium) cycling requires the recovery of these valuable resources from human urine. As nitrogen and phosphorus are valuable nutrients needed for plant growth, these components of urine are an excellent fertilizer. Phosphorus can be applied in natural fertilizers and in addition the pollution load of wastewater treatment plants is reduced. Different nutrient removal and recovery methods from urine have been studied at lab scale, but none so far has reached technological competence and none has been extended to practical use. The focus of this study was to evaluate electrocoagulation as a process for the removal of phosphate from fresh human urine using iron plate electrodes. The effect of pH and current density on phosphate removal was investigated. While determining the optimum conditions for removal, classical and chemometric methods were compared. Using the central composite design (CCD), optimum conditions were determined with only 13 experiments, and time and labour savings were achieved compared to the classical method. Initial pH values and current density were controlled within the range of pH 5-9 and current density 12-40 mA/cm². From the obtained results, it was found that optimal initial current density is 40 mA/cm² for both methods, and optimal pH is 7 for the classical method and 6.24 for CCD, which is the natural pH of human urine. Realization of phosphate removal using optimum conditions discovered with CCD, provides savings on experimental effort, time, chemicals and energy consumption, and will contribute to resource recovery, reduction of wastewater load and sustainable fertilizer production.