ABSTRACT: Cadmium (Cd) is a heavy metal that is extremely dangerous to human health and can be found naturally in soils, deposited through industrial waste or phosphate fertilization. In this study, we evaluated the morphological responses of in vitro grown plants of potato in the presence of Cd, and define a procedure for assessing Cd sensitivity of different clones. The potato clone SMIJ461-1 was cultured in the presence of Cd at concentrations of 0, 20, 40, 60, 80, 90, 110, 120, 140, and 160 µM. Survival, rooting, number and height of shoots, leaf and root counts were evaluated at 7, 14, 21, and 28 days of cultivation. Adverse effects of Cd on the growth of the potato plants, exerted in a concentration-dependent manner, were observed for shoot height, leaf and root counts. Results of this study indicated that Cd concentrations of 0, 45, 90, and 135 µM can be used for future in vitro evaluation of potato clone sensitivity to Cd exposure.

RESUMO: O cádmio (Cd) é um metal pesado extremamente perigoso à saúde humana, podendo ser encontrado naturalmente nos solos, depositado através de resíduos industriais ou da adubação fosfatada. Este trabalho teve por objetivo avaliar as respostas morfológicas de plantas de batata cultivadas in vitro na presença de Cd e definir uma metodologia para inferir sobre a sensibilidade de diferentes clones. Foi estudado o clone SMIJ461-1 de batata, nas concentrações de 0, 20, 40, 60, 80, 90, 110, 120, 140, 160 µM de Cd adicionadas ao meio de cultura. A sobrevivência, o enraizamento, o número de brotações, a altura da parte aérea e o número de folhas e raízes foram avaliados aos 7, 14, 21 e 28 dias de cultivo. Foram observados efeitos adversos de concentrações de Cd sobre o crescimento in vitro das plantas de batata do clone SMIJ461-1 para a altura da parte aérea e o número de folhas e raízes, sendo estes efeitos dependentes das concentrações de Cd adicionadas ao meio de cultura. Os resultados deste estudo indicam que as concentrações de 0, 45, 90 e 135 µM de Cd podem ser utilizadas para a avaliação in vitro da sensibilidade de clones de batata a presença de Cd.

ABSTRACT: Acacia mearnsii De Wild. (Black wattle) is a forest species with great social and economical importance for the southern region of Brazil. This species has multifunctional characteristics, being cultivated to produce tannin, cellulose and energy. This research identified black wattle genotypes with competence for adventitious rooting for mini-cutting propagation. Single-bud mini-cuttings were treated with IBA at a concentration of 2000 mg L-1. After 30 days of cultivation in a humid chamber, the mini-cuttings were evaluated for percentages of survival, rooting, number of roots, average length of the three largest roots, and the number of mini-cuttings rooted per mini-stump. The identification of the best genotypes was performed with the Selegen REML/BLUP software. Selection between and within black wattle progenies can be performed based on the number of rooted mini-cuttings, making it possible to select genotypes with high competence for adventitious rooting while maintaining genetic variability for new selection cycles to develop clones for vegetative propagation by mini-cutting.

RESUMO: Acacia mearnsii De Wild. (Acácia-negra) é uma espécie florestal de grande importância social e econômica para a região sul do Brasil. Essa espécie apresenta características multifuncionais, sendo cultivada para produção de tanino, celulose e energia. Este trabalho teve por objetivo identificar genótipos de acácia-negra com competência ao enraizamento adventício para a propagação por miniestaquia. Miniestacas de gema única foram tratadas com AIB na concentração de 2000 mg L-1. Aos 30 dias de cultivo as miniestacas foram avaliadas quanto às porcentagens de sobrevivência e enraizamento, número e comprimento médio das três maiores raízes e número de miniestacas enraizadas por minicepa. A identificação dos melhores genótipos foi realizada com o auxílio do software Selegen REML/BLUP. A seleção entre e dentro de progênies de acácia-negra pode ser realizada para o número de miniestacas enraizadas, sendo possível selecionar genótipos com alta competência ao enraizamento adventício, mantendo variabilidade genética para novos ciclos de seleção, visando desenvolver clones para a propagação vegetativa por miniestaquia.

Resumo O objetivo deste trabalho foi avaliar a concentração de ácido indolbutírico (AIB), a composição e o volume do substrato, e o tipo de propágulo no enraizamento adventício e na qualidade de mudas de Cordia trichotoma produzidas por miniestaquia. As miniestacas foram avaliadas quanto à percentagem de enraizamento e número e comprimento de raízes aos 30 e 60 dias de cultivo. Já as mudas foram avaliadas quanto à altura da parte aérea e diâmetro do colo aos 30, 60, 90 e 120 dias de cultivo. O índice de qualidade de Dickson, o número de folhas, e a massa fresca e seca da parte aérea e das raízes também foram determinados aos 120 dias de cultivo. Os experimentos foram conduzidos em delineamento inteiramente casualizado, com seis repetições, em casa de vegetação, tendo-se avaliado diferentes concentrações de AIB, composição e volume do substrato, e tipo de propágulo no enraizamento adventício. As mudas de C. trichotoma podem ser produzidas com qualidade e enraizamento adequado a partir de miniestacas de uma ou duas gemas ou de múltiplas gemas (apicais) quando tratadas com 3.000 mg L-1 de AIB e plantadas em tubetes de 110 cm3 contendo igual proporção de substrato comercial e vermiculita.

Abstract The objective of this work was to evaluate the effects of indolebutyric acid (IBA) concentration, substrate composition and volume, and propagule type on the adventitious rooting and quality of Cordia trichotoma plantlets produced by mini-cuttings. Mini-cuttings were evaluated for rooting percentage and root number and length at 30 and 60 days of cultivation. Plantlets were evaluated for shoot height and stem diameter at 30, 60, 90, and 120 days of cultivation. The Dickson quality index, number of leaves, and fresh and dry weights of shoots and roots were also determined at 120 days of cultivation. The experiments were carried out in a completely randomized design, with six replicates, in a greenhouse, evaluating different concentrations of IBA, substrate composition and volume, and propagule type for adventitious rooting. Plantlets of C. trichotoma can be produced with quality and proper rooting from mini-cuttings with one or two buds or multiple buds (apical) when treated with 3,000 mg L-1 IBA and planted in 110 cm3 tubes containing equal proportions of substrate and vermiculite.

Abstract Acacia mearnsii De Wild. is one of the most widely cultivated forest species in Brazil. Despite its importance, studies on breeding strategies for this species are scarce. Therefore, the aim of this study was to evaluate the progeny and develop early selection strategies for A. mearnsii. Individuals of half-sib progenies were classified according to their genotypic value and selected based on their relative performance. The additive effect was only significant for plant height. The best progenies and plants should be selected based on plant height after approximately 60 days of being in nursery and 2 years of field cultivation. This strategy eliminates the worse progenies, discards inferior genotypes in the nursery, eliminates unselected genotypes based on plant height before flowering, and intercrosses only the best plants in field cultivation. This resulted in an annual genetic gain of 3% for plant height and 2% for diameter at breast height.

ABSTRACT In this study, we evaluated the adventitious rooting competence of mini-cuttings and plantlet growth of two clones of swamp cork (Erythrina crista-galli L.). Experiments were carried out in a factorial of two clones to study the need of application of indolebutyric acid (IBA), substrate composition for mini-cutting rooting and plantlet growth, and rooting curves of the clones 15SM05 and 15SM08, in the completely randomized design. Mini-cuttings of swamp cork clones showed high rooting competence, with mean rooting percentage above 80% even without IBA application. Vermiculite and its combination with commercial substrate resulted in the highest percentage of rooting, and number and length of roots and shoots. The clones showed differences regarding their adventitious rooting competence and the increment in rooted mini-cuttings with time in a humidity chamber, being the clone 15SM05 the most suitable for plantlet production.

Resumo 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.

Abstract Apuleia leiocarpa Vogel J. F. Macbr. is a tree species native to Brazil that has high wood quality, and is currently threatened with extinction. Seminal seedlings of grápia are rarely commercialized, and vegetative propagation techniques, such as micropropagation, are considered as alternative methods for the production of grápia trees. However, there is a lack of available information about the in vitro introduction of nodal segments, and little information is available regarding in vitro rooting of grápia trees. As such, there are knowledge gaps that need to be addressed in order to define a micropropagation protocol for this species. Thus, the objective of this study was to evaluate different disinfestation solutions in the introduction of nodal segments and of different types and concentrations of auxins in the in vitro rooting of grápia explants. For the introduction of nodal segments, different types of disinfestation solutions and immersion times were evaluated. For rooting, different concentrations and types of auxins were evaluated. The best disinfestation treatment was found to be immersion in sodium hypochlorite (NaOCl) solution with 2.5% active chlorine for 5 minutes. For rooting, treatment with 1.0 mg L-1 of naphthalene acetic acid (NAA, C10H7CH2CO2H) resulted in the highest rates of adventitious rooting. Grápia nodal segments can be established in vitro, and provide a good source of propagules for micropropagation, and rooting can be favored through the application of NAA.

ABSTRACT Cordia (Cordia trichotoma (Vell.) Arrab. ex Steud.) is a native species that has high quality wood and potential for the establishment of commercial plantations. However, its propagation by seeds is difficult, and vegetative propagation is a good alternative. The aim of this study was to evaluate the vegetative propagation of cordia by cuttings from shoots and roots. In one experiment, cuttings from shoots of adult plants were treated with 0 and 40 mM of indolbutyric acid (IBA). In other experiment, cuttings from roots of adult plants were classified by diameter as thick (2.0-3.0 cm) and thin (<2.0 cm) and treated with 0, 20, 40 and 60 mM of IBA. In other experiment, cuttings from roots of three-year-old plants were treated with 0, 20 and 40 mM of IBA. In all experiments, the percentages of survival, rooting and shooting, the number and length (cm) of shoots and roots were evaluated. Cuttings from roots and shoots of adult plants were not responsive to propagation, because they produced new shoots without rooting. Cuttings from roots of young plants differentiate roots, even without AIB application, enabling the production of cordia new plantlets.

Abstract: 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.

Abstract 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.

RESUMO: Os objetivos deste trabalho foram avaliar a competência ao enraizamento de miniestacas ao longo das quatro estações do ano e determinar o tempo de enraizamento adventício de clones de canjerana. O minijardim clonal foi estabelecido com 11 clones em um sistema fechado de cultivo. Foram realizadas avaliações do número total de miniestacas produzidas por minicepa, da percentagem de sobrevivência e de enraizamento das miniestacas, do número de raízes, do comprimento médio das raízes e contabilizado o número de miniestacas enraizadas por minicepa, ao longo das quatro estações do ano. Os dados foram submetidos à análise de variância e realizado teste de comparação de médias. Também foi elaborada a curva de enraizamento para os clones 10SM05, 12SMI25 e 12SMI43, com alta competência ao enraizamento adventício. Clones de canjerana podem ser selecionados para a competência ao enraizamento adventício das miniestacas nas diferentes estações do ano. Miniestacas de canjerana devem ser cultivadas em câmara úmida por 63 dias para o enraizamento.

ABSTRACT: The objectives of this research were to evaluate the rooting competence of mini-cuttings throughout the four seasons and to estimate the adventitious rooting time of canjerana clones. A clonal mini-garden was established with 11 clones in a closed hydroponic system. Evaluations were performed throughout the four seasons for the number of mini-cuttings produced per mini-stump, percentage of survival and rooting of mini-cuttings, number of roots, average root length, and number of rooted mini-cuttings per mini-stump. Data were submitted to analysis of variance and means were compared. A rooting curve was estimated for clones 10SM05, 12SMI25, and 12SMI43 that exhibited high competence for adventitious rooting. Our results indicated that canjerana clones can be selected for adventitious rooting competence of mini-cuttings during different seasons, and that canjerana mini-cuttings should be cultivated for 63 days in a rooting chamber.

Resumo 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 obtidas por minicepa. 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 incrementa o enraizamento das miniestacas de erva-mate. O processo rizogênico das miniestacas varia conforme o genótipo e a sazonalidade. O clone 06SM15 apresenta a maior capacidade rizogênica nas quatro épocas do ano. As melhores porcentagens de enraizamento são verificadas nas épocas do outono e/ou inverno para os quatro genótipos avaliados.

Abstract The objective of this work was to evaluate the effect of season and clone in the productivity of the mini-stumps and the rooting of mini-cuttings of erva mate (Ilex paraguariensis A. St.-Hil.) treated or not with indolbutyric acid (IBA). Mini-cuttings were collected from mini-stumps of four clones during the four seasons of the year. In each collection, it was evaluated the percentage of mini-stumps survival and the number of mini-cuttings obtained per mini-stump. Single-budded mini-cuttings were treated or not with 2000 mg L-1 IBA before planting. At 30 and 60 days, the percentages of survival, rooting and callus formation in mini-cuttings, the number and length of roots were evaluated. The mini-stumps of the four erva mate clones showed high survival. The clones 06SM17, 06SM12 and 06SM15 had a uniform production of mini-cuttings per mini-stump during the four collection times. IBA treatment is not necessary for mini-cutting rooting of these clones. The mini-cutting rooting varied with the evaluated clone and collection time. The clone 06SM15 had the highest rhizogenesis capability in the four collection times. The highest rooting percentage was obtained during fall and winter seasons for the four clones.

Resumo: O objetivo deste trabalho foi avaliar diferentes solventes e tempos de extração de polifenóis com ultrassom, para quantificar os compostos fenólicos e flavonoides totais e a capacidade antioxidante em folhas de erva-mate (Ilex paraguariensis). O experimento foi realizado em delineamento inteiramente casualizado, em arranjo fatorial 8x3 (solvente x tempo de extração). Os solventes foram água destilada e as soluções aquosas de etanol, acetona e metanol, acidificados ou não com ácido clorídrico, e os tempos de extração em banho ultrassônico foram de 15, 30 e 45 min. As extrações foram concluídas com agitação mecânica de 30 min. As amostras tratadas com solventes hidroalcoólicos acidificados apresentaram os maiores valores de compostos fenólicos e flavonoides totais e capacidade antioxidante. A extração com hidroetanol acidificado não foi afetada pelo tempo em ultrassom. Houve correlação entre os teores de compostos fenólicos e flavonoides totais e destes com a capacidade antioxidante, especialmente quando esta foi determinada pelo poder antioxidante redutor do íon ferro. O solvente hidroetanólico acidificado em ultrassom por 15 min é a condição de extração mais apropriada para a quantificação dos teores de compostos fenólicos totais e flavonoides e da capacidade antioxidante em folhas de erva-mate.

Abstract: The objective of this work was to evaluate different solvents and times in the ultrasound-assisted extraction of polyphenols, in order to quantify the total phenolic and flavonoid contents in and the antioxidant activity of mate (Ilex paraguariensis) leaves. The experiment was carried out in a completely randomized design, in a 8x3 (solvent x time of extraction) factorial arrangement. The solvent extractors were distilled water and aqueous solutions of ethanol, acetone, and methanol, acidified or not with hydrochloric acid, and the time of ultrasound-assisted extractions were 15, 30, and 45 min. All extractions were finished with a mechanical agitation of 30 min. Samples treated with acidified hydroalcoholic solvents resulted in higher values of total phenolics and flavonoids and antioxidant activity. The extraction using acidified hydroethanol solvent was not affected by the time in the ultrasound. The contents of total phenolics and flavonoids were highly correlated with each other and with the antioxidant activity, especially when it was determined by the ferric-reducing antioxidant power method. Acidified hydroethanol solvent in ultrasound for 15 min is the most suitable extraction condition for the quantification of the contents of total phenolics and flavonoids in and the antioxidant activity of mate leaves.

Resumo: O objetivo deste trabalho foi definir uma estratégia de seleção precoce para identificar clones de Cabralea canjerana (Meliaceae) com alta taxa de multiplicação. Um minijardim com 109 clones de plântulas de canjerana foi estabelecido com um delineamento inteiramente casualizado em casa de vegetação climatizada. Das plântulas, foram obtidas as minicepas e as miniestacas. As miniestacas foram coletadas em cinco épocas, e foram quantificados o número total de miniestacas por minicepa, a percentagem de enraizamento e o número de miniestacas enraizadas. O número de miniestacas enraizadas por minicepa foi o único caráter que apresentou alta correlação com os demais. Foram estabelecidos cinco grupos de clones com base no número de miniestacas enraizadas por minicepas, pelo agrupamento das k-médias, e estimados o ganho genético de seleção e a correlação de Pearson. A seleção dos dois melhores grupos em cada época resultou em altos ganhos de seleção para os caracteres avaliados. A seleção precoce para o número de miniestacas enraizadas descartou 65% dos clones avaliados, o que aumenta a precisão experimental em avaliações de caracteres associados ao crescimento e à qualidade das mudas. A seleção precoce do número de miniestacas enraizadas por minicepas, em diferentes épocas, permite identificar clones de Cabralea canjerana com alta taxa de multiplicação.

Abstract: The objective of this work was to define an early selection strategy to identify Cabralea canjerana (Meliaceae) clones with high multiplication rate. A mini-garden of 109 clones of canjerana seedlings was established in a completely randomized design, in an acclimatized greenhouse. From seedlings, the mini-stumps and mini-cuttings were obtained. Mini-cuttings were collected at five different times, and the number of mini-cuttings per mini-stump, rooting percentage, and number of rooted mini-cuttings were quantified. The number of rooted mini-cuttings per mini-stump was the only trait that showed high correlation with the others. Five groups of clones based on the number of rooted mini-cuttings per mini-stump were separated using k-means clustering, and the genetic gain from selection and Pearson correlation were estimated. The selection of the two best groups in each evaluation period resulted in high genetic gains from selection for all evaluated traits. Early selection for the number of rooted mini-cuttings discarded 65% of the evaluated clones, which increases experimental precision in evaluations of traits associated with plantlet growth and quality. Early selection for the number of rooted mini-cuttings per mini-stump at different times allows the identification of Cabralea canjerana clones with high multiplication rate.

RESUMO 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 acrescido 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.

ABSTRACT The aim of this work was to evaluate the in vitro productivity of grapia (Apuleia leiocarpa) micro-stumps cultivated in different media conditions to maximize its multiplication rate. Micro-stumps from aseptic seedlings were cultivated in WPM medium added with 0, 2.2, 4.4, 6.6 and 8.8 µM of 6-benzylaminopurine (BAP) and subcultured in WPM medium without cytokinin. Micro-stumps were also cultivated in WPM, MS or ½ MS base media with or without the addition of 1.5 g L-1 of activated charcoal and submitted to drastic pruning at 30, 60 and 90 days of cultivation. The in vitro cultivation of grapia micro-stumps in WPM or ½ MS media added with 8.8 µM of BAP and the subcultivation in media without cytokinin increase the number and length of shoots. The cultivation of grapia micro-stumps in media with activated charcoal increases the productivity of micro-cuttings per micro-stumps, but in the absence of activated charcoal induces callus formation and indirect organogenesis of shoots. The in vitro conservation of grapia microstumps maximizes the multiplication rate, being a feasible technique for the production of grapia plantlets.

RESUMO A competência ao enraizamento adventício é essencial para viabilizar o resgate vegetativo de plantas adultas de erva-mate (Ilex paraguariensis St. Hil.). Os objetivos deste trabalho foram avaliar plantas adultas de erva-mate para a competência ao enraizamento adventício e estudar o resgate destas plantas, por estaquia de brotações epicórmicas, induzidas em diferentes posições do tronco. Sete plantas adultas foram avaliadas quanto à porcentagem de sobrevivência e enraizamento das estacas, oriundas de brotações induzidas pelo anelamento do tronco. Duas plantas que apresentaram a maior competência ao enraizamento foram submetidas à poda da parte aérea e ao anelamento da base, para estimular novas brotações epicórmicas e avaliar o efeito da posição de coleta no enraizamento das estacas. O resgate por estaquia, das mesmas plantas, também foi estudado em brotações epicórmicas induzidas pela decepa. As brotações foram seccionadas em estacas de gema única, tratadas ou não com 3.000 mg L-1 de ácido indolbutirico e mantidas em câmara úmida por 60 dias. As estacas foram avaliadas quanto as porcentagens de sobrevivência e enraizamento. Concluiu-se que é possível resgatar plantas adultas de erva-mate por estaquia de brotações epicórmicas induzidas por poda, anelamento ou decepa. Plantas adultas de erva-mate diferem quanto a competência ao enraizamento adventício das estacas e também quanto a posição de coleta das brotações epicórmicas.

ABSTRACT The competence of adult plants of mate (Ilex paraguariensis St. Hil.) to undergo adventitious rooting is essential to their vegetative rescue by cuttings. This study aimed to evaluate the adventitious rooting competence of adult mate plants, and then rescue these plants by making cuttings from epicormic shoots induced in different trunk positions. The percent survival and rooting of cuttings from epicormic shoots induced by girdling in seven adult plants were evaluated. The two stock plants whose cuttings had the highest rooting competence were further pruned and girdled to evaluate the effect of the position of epicormic shoots on their adventitious rooting competence. The potential success of rescuing of the same adult plants was also studied with cuttings of epicormic shoots induced by coppicing. The shoots were sectioned in single-bud cuttings, either treated with 3,000 mg L-1 indolebutyric acid or untreated, and then cultivated in a humid chamber for 60 days, and then the percent survival and rooting of cuttings was evaluated. In conclusion, we found that it is possible to rescue adult mate plants by cuttings from epicormic shoots induced by pruning, girdling, or coppicing. The adventitious rooting competence of cuttings differs among adult mate plants, and depends on the position of the epicormic shoots on the trunk from which epicormic shoots are collected.