Abstract Hyptis australis is a species of the Lamiaceae family, endemic to the Atlantic Forest, whose conservation status is critical and its potential benefits for the ecosystem and society are still unknown. For rescue and conservation purposes (ex situ/in situ), the need arises to generate a vegetative propagation protocol to facilitate and increase the availability of plants. With this objective, factors such as the type of substrate, type of stake and hormone were studied. One-year-old plants were used, obtained from seeds harvested from plants located in the southern region of the province of Misiones (Argentina). Apical and subapical cuttings were used in two trials, the first studied the feasibility of inducing adventitious roots in pine bark, sand and perlite substrates. In the second test, the induction of rhizogenesis was evaluated in cuttings treated for 30 minutes with a solution of 100 mg.kg-1 of naphthalenacetic acid (ANA) or indole butyric acid (IBA) in pine bark. The best results were obtained in the sand substrate and in the terminal stakes. ANA was the hormone that generated the highest percentage of apical cuttings (80.00±14.14%) and subapical (84.00±16.73%) with roots. In the subapical cuttings the sprouting percentage was higher in both experiments. The probability that an H. australis cuttings will develop adventitious roots depends on the type of substrate, but the addition of ANA notably improves the rooting percentage.

Resumen Hyptis australis es una especie de la familia Lamiaceae, endémica del Bosque Atlántico, cuyo estado de conservación es crítico y se desconoce aún sus beneficios potenciales para el ecosistema y la sociedad. Con fines de rescate y conservación (ex situ/in situ), se plantea como necesidad, generar un protocolo de propagación vegetativa para facilitar y aumentar la disponibilidad de plantas. Con este objetivo, se estudiaron factores como el tipo de sustrato, tipo de estaca y hormona. Se utilizaron plantas de un año de edad, obtenidas de semillas cosechadas de las plantas ubicadas en la región sur de la provincia de Misiones (Argentina). Estacas apicales y subapicales fueron utilizadas en dos ensayos, en el primero se estudió la factibilidad de inducir raíces adventicias en los sustratos corteza de pino, arena y perlita. En el segundo ensayo, se evaluó la inducción de rizogénesis en estacas tratadas durante 30 minutos con una solución de 100 mg.kg -1 de ácido naftalenacetico (ANA) o ácido indolbutirico (AIB) en corteza de pino. Los mejores resultados se obtuvieron en el sustrato arena y en las estacas terminales. El ANA fue la hormona que generó mayor porcentaje de estacas apicales (80.00±14.14 %) y subapicales (84.00±16.73 %) con raíces. En las estacas subapicales el porcentaje de brotación fue mayor en ambos experimentos. La probabilidad de que una estaca de H. australis desarrolle raíces adventicia depende del tipo de sustrato, pero la adicción de ANA mejora notablemente el porcentaje de enraizamiento.

Resumen Hedeoma teyucuarensis es una especie microendémica del único fragmento del bioma Cerrado de la Argentina desarrollado sobre areniscas. Se encuentra en peligro crítico dado que es utilizada en medicina popular para combatir los parásitos intestinales. El objetivo del presente estudio es evaluar la factibilidad de obtener plantas madre de H. teyucuarensis a partir de estacas, empleando diferentes concentraciones de ácido 1-naftalenacético (ANA) en arena, perlita y corteza de pino. Se cosecharon estacas de plantas ubicadas en su área de distribución natural (San Ignacio, Misiones, Argentina). Posteriormente, del material vegetal cosechado, se obtuvieron estacas apicales y subapicales de un largo de 7 cm. Las bases de estas son sumergidas en una solución de ANA en las dosis 0, 100 y 250 mg.kg-1, durante 30 minutos y luego en una solución fúngica por 20 minutos. Las estacas son colocadas en macetas de 200 cm3, que contienen como sustrato, arena, perlita y corteza de pino. El mayor porcentaje de enraizamiento se obtiene en las estacas del tratamiento testigo. La concentración de ANA no afecta el porcentaje de enraizamiento, pero si en el número de raíces. Este trabajo ha demostrado que el tipo de estaca como de sustrato utilizado afecta el enraizamiento y por ende la obtención de plantas. Este estudio aporta una metodología de propagación vegetativa para obtener plantas, el cual puede servir para conservar esta especie en peligro.

Abstract Hedeoma teyucuarensis is a microendemic species of the only fragment of the Cerrado Biome of Argentina developed on sandstones. It is critically endangered because it is used in folk medicine to combat intestinal parasites. The aim of the present study is to evaluate the feasibility of obtaining H. teyucuarensis mother plants from cuttings, using different concentrations of 1-naphthaleneacetic acid (NAA) in sand, perlite, and pine bark. Cuttings are harvested from plants located in its natural distribution area (San Ignacio, Misiones, Argentina). Subsequently, apical and subapical cuttings 7 cm long are obtained from the harvested plant material. The bases of these are immersed in a solution of NAA at doses of 0, 100 and 250 mg/kg-1 for 30 minutes and then in a fungal solution for 20 minutes. The cuttings are placed in 200 cm3 pots containing sand, perlite, and pine bark as substrate. The highest percentage of rooting is obtained in the cuttings of the control treatment. The concentration of NAA did not affect the rooting percentage but did affect the number of roots. This work has shown that the type of stake and substrate used affects rooting and therefore the obtaining of plants. This study provides a methodology of vegetative propagation to obtain plants, which can be used to conserve this endangered species.

ABSTRACT Yerba mate is a tree species whose natural distribution occurs in the countries of Argentina, Paraguay, and Brazil, where most of the plantations are concentrated. For the establishment of plantations seedlings are commonly used. But alternatively, there are ex vitro vegetative propagation techniques like mini-cuttings technology, which has the potential to facilitate plant production and increase the amount of plants needed for the industry. Yerba mate is sensitive to drought stress, negatively affecting the plantation productivity. Therefore, the objective of this work was to evaluate the growth and physiological responses of yerba mate seedlings and mini-cuttings to conditions of drought stress (field capacity, moderate drought, and severe drought). Total height, diameter at root collar, accumulation of dry weight (roots, leaves and stem), leaf number and area, and the content of chlorophylls were measured as response variables. Drought stress produced a decrease in height, dry wight accumulation, leaf number and area, and chlorophyll content, which was more pronounced in a situation of severe stress. The comparative analysis did not detect significant differences between seedlings and mini-cuttings, and there was also no interaction between the water restricted factors under consideration and type of propagule.

RESUMO A produção de mudas de erva-mate através de sementes tem várias limitações, que podem ser superadas por técnicas de propagação vegetativa ex vitro, como miniestacas, nas quais geralmente é necessário o uso de fertilizantes químicos sintéticos e fungicidas. Portanto, há uma tendência para a agricultura sustentável, usando biofertilizantes (bactérias promotoras de crescimento) e biocontroladores (Trichoderma sp.). Portanto, os objetivos deste trabalho foram avaliar o efeito dos biofertilizantes na produção de miniestacas a partir de minicepas de erva-mate; bem como o efeito dos biocontroladores na sobrevivência e na capacidade de enraizamento de miniestacas. Bacillus sp. e Trichoderma asperelloides de erva-mate foram utilizados sob duas condições de radiação. Houve uma relação positiva entre a disponibilidade de radiação e a produção de miniestacas e a capacidade de enraizamento. Todos os minicepas brotaram independentemente dos tratamentos. A maior produção de miniestacas viáveis ocorreu em uma situação de alta radiação e fertilização; enquanto os tratamentos com bactérias promotoras de crescimento e alta radiação apresentaram valores intermediários. As miniestacas inoculadas com Trichoderma asperelloides apresentaram maior porcentagem de enraizamento, maior número e longitude de raízes que as miniestacas tratadas com fungicida. Portanto, provamos que o uso de produtos químicos pode ser substituído por produtos biológicos e esse fato atingem alcança rendimentos aceitáveis.

ABSTRACT The production of yerba mate seedlings through seeds has several limitations, which can be overcome by ex vitro vegetative propagation techniques such as the mini-cuttings, in which it is usually necessary to use synthetic chemical fertilizers and fungicides. However, there is a tendency towards sustainable agriculture, using biofertilizers (growth-promoting bacteria) and biocontrollers (Trichoderma sp.). Therefore, the objectives of this work were to evaluate the effect of biofertilizers on the production of mini-cuttings from yerba mate mini-stumps; as well as the effect, of biocontrollers on survival and rooting capacity of mini-cuttings. Strains of Bacillus sp. and Trichoderma asperelloides of yerba mate were used under two radiation conditions. There was a positive relationship between the availability of radiation and the production of mini-cuttings and the rooting capacity. All the mini-stumps sprouted regardless of treatments. The largest production of viable mini-cuttings occurred in a situation of high radiation and fertilization; while the treatments with growth-promoting bacteria and high radiation had intermediate values. The mini-cuttings inoculated with Trichoderma asperelloides had higher rooting percentage, greater number and length of roots than the mini-cuttings treated with fungicide. Therefore, we demonstrated that the use of chemical products can be replaced by biological ones and achieves acceptable yields.

RESUMEN Phaius tankervilleae es una orquídea terrestre altamente apreciada como ornamental y medicinal, razón por la cual se encuentra en peligro de extinción en algunos países como Australia y Japón. Generar información sobre las dimensiones y el vigor de la semilla es importante para entender aspectos de la evolución de la especie y encontrar métodos de conservación. Este estudio tuvo como finalidad poner a prueba la hipótesis, de que el tamaño y viabilidad de las semillas de P. tankervilleae están positivamente relacionados con el tamaño del fruto. Para realizar el estudio se cosecharon frutos de diferentes tamaños, de los cuales se tomaron muestras de 2,5 mg de semillas por frutos. Se realizó la caracterización morfológica de las semillas mediante observaciones en microscopio. Las semillas de cada tamaño de fruto fueron sometidas a un test de Tetrazolio para determinar viabilidad y se les tomaron mediciones del largo, ancho y volumen tanto de la testa como del embrión. Las semillas con embrión son fusiformes y las vanas son filiformes, el embrión es relativamente pequeño y las semillas de fruto mediano son las que presentan menor espacio de aire. Los resultados confirman la hipótesis planteada, cuanto más pequeño es el fruto menor es el tamaño y la cantidad de semillas viables. Por consiguiente, si se desea tener mayor cantidad de semillas de buena calidad es recomendable cosechar frutos de mayor tamaño.

ABSTRACT Phaius tankervilleae is a terrestrial orchid highly prized as ornamental and medicinal, which is why it is in danger of extinction in some countries such as Australia and Japan. Generating information on seed size and vigor is important in understanding aspects of the evolution of the species and finding conservation methods. This study aimed to test the hypothesis that the size and viability of P. tankervilleae seeds are positively related to fruit size. In order to carry out the study, fruits of different sizes were harvested, from which samples of 2.5 mg of seeds per fruit were taken. Morphological characterization of the seeds was carried out by means of microscope observations. A Tetrazolium test was carried out to determine the viability of seeds and measurements were taken of the length, width, and volume of both the testa and the embryo. Seeds with embryos are fusiform and the empty one are filiform, the embryo is relatively small and the seeds of medium size fruit are those that have less air space. The results confirm the hypothesis, the smaller the fruit the smaller the size and the number of viable seeds. Therefore, to have more seeds of good quality it is advisable to harvest larger fruits.