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Apuleia leiocarpa Vogel J. F. Macbr. é uma espécie arbórea nativa do Brasil que possui madeira de alta qualidade e, atualmente, se encontra ameaçada de extinção. Mudas seminais de grápia dificilmente são comercializadas, sendo técnicas de propagação vegetativa, a exemplo da micropropagação, uma alternativa a ser considerada para produção de mudas. No entanto, há uma falta de informação disponível sobre a introdução in vitro de segmentos nodais e pouca informação está disponível sobre o enraizamento adventício de grápia. Como tal, existem lacunas de conhecimento que precisam ser abordadas para definir um protocolo de micropropagação para essa espécie. Assim, o objetivo deste estudo foi avaliar diferentes soluções de desinfestação na introdução de segmentos nodais e de diferentes tipos e concentrações de auxinas no enraizamento in vitro de explantes de grápia. Para a introdução, foram testados diferentes tipos de solução de desinfestação e tempos de imersão. Para o enraizamento, foram avaliadas diferentes concentrações e tipo de auxina. O melhor tratamento de desinfestação foi a imersão em solução de hipoclorito de sódio (NaOCl) a 2,5% de cloro ativo por 5 minutos. Para o enraizamento, o tratamento com 1,0 mg L-1 de ácido naftalenoacético (ANA, C10H7CH2CO2H) resultou nas maiores taxas enraizamento adventício. Os segmentos nodais de grápia podem ser estabelecidos in vitro, consistindo em boa fonte de propágulos para a micropropagação, e o enraizamento pode ser favorecido pela aplicação de ANA.

Mate (Ilex paraguariensis A. St.-Hil) is an arboreal species of great economic and socio-environmental importance, which presents difficulties in the adventitious rooting process. The rhizogenic competence of vegetative propagules of mate can be attained by coppicing, but the factors that influence the success of this technique have not yet been elucidated. Therefore, the aim of this study was to evaluate the effects of the stock plant, time of shoot collection, treatment with indolebutyric acid (IBA) and diameter of vegetative propagules in the adventitious rooting of cuttings from shoots induced by coppicing of selected adult plants of mate. Shoots produced from coppiced 13SM01 and 13SM05 stock plants were collected at different times of the year to prepare single-bud cuttings. The cuttings were measured as their diameter in the central portion and treated with 0 and 3000 mg L-1 of IBA. After 60 days, cuttings were evaluated to determine survival and rooting percentages, number of roots, and length of the three largest roots. A completely randomized design was used in a 4 × 2 × 2 × 13 (collection times x stock plants x IBA treatment x diameter classes) factorial scheme with 15 replications. Competence for adventitious rooting was highest for stock plant 13SM05. Cuttings collected in November and February had the highest rooting percentages, without the need of IBA treatment. Cuttings from 13SM01 and 13SM05 with diameters smaller than 0.636 cm (classes 1 to 6) and smaller than 0.712 cm (classes 1 to 7), respectively, had the highest rooting percentages and differed significantly from cuttings with larger diameters. Thus, the results of the present study indicate that stock plants, time of shoot collection, and diameter of vegetative propagules influence adventitious rooting competence of mate cuttings from coppicing adult plants. Rooting of mate cuttings with lower rhizogenic competence is influenced by the application of 3000 mg L-1 of IBA.

As the energizing and therapeutic effects of infusions of mate (Ilex paraguariensis A.St.-Hil) leaves are increasingly recognized, rising global consumption is also increasing the demand for plantlets with high genetic and morphological qualities. Mini-cuttings are an alternative for clonal plantlets; however, more details are needed on factors that affect the success of this technique. Here, toward maximizing production, we evaluated adventitious rooting competence of mini-cuttings of different sizes and the morphophysiological quality of the resultant plantlets. Small (one bud; length up to 2.5 cm), medium (multiple buds; length 2.6–5.0 cm), and large (multiple buds; length 5.1–10.0 cm) mini-cuttings were planted in a mixture of commercial substrate, vermiculite, and coarse sand (1:1:1 v:v:v), grown in a humidity chamber, then evaluated after 45, 60, 75, and 90 days for survival, percentage of callus and shoot formation, number and length of shoots, percentage of rooted cuttings, and number and length of roots. Any rooted mini-cuttings were then cultivated in commercial substrate and subsurface soil (2:1 v:v) and evaluated after 30, 60, 90 and 120 days of cultivation for morphophysiology of the plantlets, percentage of survival, number of leaves, shoot height, stem diameter, and ratio of shoot height to stem diameter. After 120 days, the plantlets were evaluated for the ratio of shoot and root dry mass, total length, surface area, total volume, and mean diameter of roots and Dickson quality index. Adventitious rooting of the mini-cuttings and the morphophysiological quality of the plantlets were not influenced by the size of the vegetative propagule. Therefore, single-bud mini-cuttings have similar adventitious rooting competence, and result in plantlets with adequate morphophysiological quality, based upon leaf development, shoot height, stem diameter and length, and surface area, volume and diameter of roots. Single-bud mini-cuttings up to 2.5 cm long can thus be used to maximize production of mate plantlets by mini-cuttings.

O objetivo deste trabalho foi avaliar o efeito de épocas do ano e de clones na produtividade das minicepas e no enraizamento de miniestacas de erva-mate (Ilex paraguariensis A. St. - Hil.) tratadas ou não com ácido indolbutírico (AIB). Com esta finalidade, nas quatro épocas do ano realizou-se a coleta de brotos das minicepas de quatro clones de erva-mate, sendo que em cada coleta foi avaliada a porcentagem de sobrevivência das minicepas e o número de miniestacas. Posteriormente, os brotos foram seccionados em miniestacas de gema única, as quais foram ou não tratadas com 2000 mg L-1 de AIB. Aos 30 e 60 dias foram avaliadas as porcentagens de sobrevivência, enraizamento e calogênese, número e comprimento das raízes. As minicepas dos quatro clones de erva-mate apresentaram alta sobrevivência, além de produção constante de miniestacas dos clones 06SM17, 06SM12 e 06SM15 durante as quatro épocas do ano. O tratamento com AIB não incrementou no enraizamento das miniestacas de erva-mate. O processo rizogênico das miniestacas variou conforme o genótipo e a sazonalidade. O clone 06SM15 apresentou a maior capacidade rizogênica nas quatro épocas do ano. As melhores porcentagens de enraizamento foram verificadas nas épocas do outono e/ou inverno para os quatro genótipos avaliados.

This study aimed to evaluate half-sibling progenies for developing breeding strategies and to select mate clones with adventitious root competence, required for vegetative propagation by mini-cuttings. For rooting, single-bud mini-cuttings of 2 cm length were treated with indolebutyric acid at 2000 mg L-1. At 60 days of cultivation, the mini-cuttings were evaluated for percentages of survival and rooting, number and mean length of the three largest roots, and number of rooted mini-cuttings per mini-stump. These data were analyzed considering the mixed model described for a completely randomized design, an environment, half-sibling progenies, and a single plant per plot, by using the SELEGEN-REML/BLUP software. The 50 genotypes with the highest number of rooted mini-cuttings were selected. The genetic gain was 48.41% for the number of rooted mini-cuttings per mini-stump. Selection for adventitious rooting based on the number of rooted mini-cuttings can be used in mate breeding programs for vegetative propagation by mini-cuttings.

Leaves of mate is one of the main non-timber forest products marketed in South America, which makes establishment of new plantations of great interest. However, vegetative propagation of mate plantlets presents difficulties, which may be associated with the complexity of adventitious root formation. The aims of this study were to anatomically characterize the adventitious roots of mate-clone mini-cuttings and investigate the relationship of phenols and starch with adventitious rooting competence in mini-cuttings treated or not with indole-butyric acid (IBA). The mini-cuttings of four clones were collected at 0, 30, and 60 days of cultivation, fixed in a solution containing 1% glutaraldehyde and 4% formaldehyde, pre-infiltrated and infiltrated in (2-hydroxyethyl) methacrylate, and sectioned in a microtome. Ferric chloride and toluidine blue were used to detect phenolic compounds and lugol to identify starch. Adventitious roots formed in mini-cuttings treated with IBA presented disorganized xylem and phloem and poles irregularly but exhibited sclerenchyma vessel elements and tracheid cells indicating functionality. Differences in the rhizogenic ability of mate clones mini-cuttings were not due to the presence of anatomical barriers or the accumulation of phenolic compounds but be associated with the presence and distribution of starch grains in vegetative propagules.

O objetivo deste trabalho foi avaliar a produtividade de microcepas de grápia (Apuleia leiocarpa) mantidas em diferentes condições de cultivo in vitro, visando maximizar a taxa de multiplicação. Microcepas oriundas da poda drástica de plantas assépticas foram cultivadas em meio de cultura WPM acrescida de 0; 2,2; 4,4; 6,6 e 8,8 µM de 6-benzilaminopurina (BAP) e subcultivadas em meio de cultura WPM sem citocinina. Microcepas de grápia também foram cultivadas em meio de cultura WPM, MS ou ½ MS, acrescido ou não de 1,5 g L-1 de carvão ativado e submetidas a três coletas de brotos aos 30, 60 e 90 dias de cultivo. A manutenção das microcepas em meio de cultura WPM ou ½ MS suplementado com 8,8 µM de BAP, seguido do subcultivo em meio de cultura sem citocinina aumenta o número e o crescimento de brotações. O cultivo de microcepas de grápia em meio de cultura com carvão ativado aumenta a produção de microestacas por microcepas, enquanto a ausência de carvão ativado favorece a formação de calos e brotos por organogênese indireta. A manutenção in vitro de microcepas de grápia maximiza a taxa de multiplicação, constituindo-se de uma técnica promissora para a produção de plantas de grápia.

The exposition of mate (Ilex Paraguariensis A. St.-Hil.) to As and Cd was investigated in plants derived from young mini-cuttings. Mate plants were cultivated in a closed soilless system, composed of coarse sand as substrate and flood fertirrigation. Plantlets were fertirrigated with nutritive solution and As and Cd solutions were added to the nutritive solution in the final concentration of 8 and 17 mg L-1 (As) and of 17 and 33 mg L-1 (Cd) during 14 days. Results show that stem diameter and Dickson quality index (DQI) variables could not be used as a potential indicator of accumulation of As and Cd. The shoot height, number of leaves and chlorophyll index are variables easy and quick to measure and they can be used as parameters to evaluate the stress caused in mate plants cultivation in a closed soilless system. The highest concentration of As and Cd was in roots of plants. Beyond the roots, As and Cd also can be translocated to the leaves achieving high concentrations. In addition, leaves from the treated mate plants were submitted to a hot infusion extraction in order to simulate the traditional beverage and As and Cd were determined in the infusion. Regarding to the infusion procedure, considerable As and Cd amounts were extracted from the leaves leading to conclude that this way of consumption can be an important source of toxic elements for the human diet.

This study aimed to evaluate the rooting capability of apical and nodal mini-cuttings of ipe-roxo ( Handroanthus heptaphyllus ) in different substrates. Shoots produced from mini-stumps were fractioned into mini-cuttings 2-cm long apical or nodal mini-cuttings and treated with 1000 mg L-1 of indolebutyric acid (IBA). Four substrate combinations were evaluated: commercial substrate composed of pine bark and vermiculite in proportions of 1:1, 2:1 and 1:2 (v /v) and commercial substrate, vermiculite and sand in the proportion of 1:1:1 (v/v). The factorial experiment utilized a completely random design, with five replicates of four mini-cuttings. Rooting, shooting and survival percentage, number and length of shoots and roots were evaluated at 60 and 90 days of growth. Commercial substrate and vermiculite are a good combination for rooting mini-cuttings of ipe-roxo. Apical and nodal mini-cuttings exhibit similar rooting behavior and both are feasible for production of ipe- roxo plantlets. RESUMO: O objetivo deste estudo foi avaliar o enraizamento de miniestacas apicais e nodais de ipê-roxo ( Handroanthus heptaphyllus ) em diferentes substratos. Brotos coletados de minicepas foram seccionados em miniestacas de 2cm de comprimento, classificadas em apical ou nodal e tratadas com 1000mg L-1 de ácido indolbutírico (AIB). Foram também testadas as composições de substrato comercial à base de casca de pinus e vermiculita nas proporções de 1:1; 2:1 e 1:2 (v/v) e de substrato comercial, vermiculita e areia grossa (1:1:1 v/v). O experimento foi um fatorial no delineamento inteiramente casualizado, com cinco repetições de quatro miniestacas. A porcentagem de enraizamento, de brotação e de sobrevivência, o número e comprimento de brotos e raízes foram avaliados aos 60 e 90 dias. Miniestacas de ipê-roxo cultivadas em substrato comercial e vermiculita apresentam maior capacidade de enraizamento. Miniestacas apicais e nodais apresentam similar comportamento de enraizamento, podendo ambas serem utilizadas para a produção de mudas de ipê-roxo.

O objetivo deste trabalho foi avaliar o estabelecimento e crescimento in vitro de plantas de grápia (Apuleia leiocarpa (Vogel) J. F. Macbr.) em diferentes condições de cultivo. Sementes de grápia tratadas com ácido sulfúrico (H2SO4) por 20min foram imersas em etanol a 70% por 30s e em hipoclorito de sódio (0; 2,5 ou 5,0% de cloro ativo) por 5, 10 ou 15min. Aos 30 dias de cultivo, as sementes foram avaliadas quanto às porcentagens de desinfestação e germinação. As plantas assépticas foram transferidas para os meios de cultura WPM, MS e ½MS e avaliadas quanto ao comprimento (cm) da parte aérea e total das raízes e ao número de segmentos nodais e folhas aos 15 dias. Sementes de grápia também foram semeadas em meio de cultura WPM, suplementado com 4, 5 ou 6g L-1 de agar combinado com 10, 20 ou 30g L-1 de sacarose, e mantidos sob duas condições de luminosidade: luz durante todo o período de estabelecimento e escuro durante sete dias após a semeadura. Foram avaliados a porcentagem de germinação das sementes, o comprimento (cm) da parte aérea e total das raízes e o número de segmentos nodais e folhas aos 15 dias. Concluiu-se que os tratamentos com ácido sulfúrico e etanol foram suficientes para o estabelecimento in vitro de plantas assépticas de grápia. Plantas assépticas podem ser cultivadas em meio de cultura WPM ou MS, suplementados com 10g L-1 de sacarose e 4g L-1 de agar. The aim of this study was to evaluate the in vitro establishment and growth of apuleia (Apuleia leiocarpa (Vogel) J. F. Macbr.) seedlings under different culture conditions. Apuleia seeds were treated with sulfuric acid (H2SO4) for 20min and disinfected by the immersion in 70% of ethanol for 30s and sodium hypochlorite with 0, 2.5 and 5.0% of active chlorine for 5, 10 and 15min. The percentage of disinfection and germination were evaluated at 30 days. Aseptic seedlings were transferred to WPM, MS and ½ MS culture medium and evaluated for shoot and root (cm) growth and number of nodal segments and leaves at 15 days. Apuleia seeds were also sown in WPM medium supplemented with 4, 5 or 6g L-1 of agar combined with 10, 20 or 30g L-1 of sucrose. The cultures were kept under two luminescence conditions: light throughout the establishment period and dark during the first seven days. The percentage of germination, shoot and root (cm) growth and number of nodal segments and leaves were evaluated at 15 days. In conclusion, the sulfuric acid and ethanol treatments were enough for the in vitro production of apuleia aseptic seedlings. The aseptic seedlings can grow in both WPM and MS medium, supplemented with 10g L-1 of sucrose and 4g L-1 of agar.