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 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 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.

Abtract Apuleia leiocarpa is an endangered tree species with high quality timber. Propagation by seed is difficult due to irregular fruiting and water-impermeable tegument, so asexual propagation is a promising alternative. This study aimed to evaluate in vitro and ex vitro rooting of A. leiocarpa and acclimatization of micropropagated plantlets. The hypothesis was that type of explant, indolebutyric acid (IBA) concentration and substrate influence the induction of adventitious roots in apuleia. For in vitro rooting, nodal segments and micro-cuttings were grown in Wood Plant Medium (WPM) with 0, 4.9, 9.8, 14.7 and 19.6 μM IBA. Compositions of commercial substrate + vermiculite + coarse sand and commercial substrate + vermiculite, in equal proportions, were tested for acclimatization. For ex vitro rooting, nodal segments and micro-cuttings were treated with 0 and 4920 μM IBA for 10 s and grown in equal proportions of: commercial substrate + vermiculite + coarse sand, commercial substrate + vermiculite, and commercial substrate + coarse sand. Nodal segments presented greater rooting in vitro than micro-cuttings without need for IBA supplementation in the culture medium. Substrate composition did not affect survival or growth of in vitro rooted plantlets during acclimatization. The best ex vitro rooting was found in nodal segments and explants treated with 4920 μM IBA and grown in commercial substrate + vermiculite + coarse sand. Ex vitro rooting is a promising technique for producing apuleia plantlets; however, adjustments to environmental conditions in both ex vitro rooting and acclimatization are necessary in order to maximize survival of micropropagated A. leiocarpa plantlets.

Resumen Apuleia leiocarpa es una especie de árbol en peligro de extinción con madera de alta calidad. Su propagación por medio de semillas es difícil por que la aparición de frutos es irregular y por el tegumento impermeable al agua; así la propagación asexual es una alternativa prometedora. El objetivo de este estudio fue evaluar el enraizamiento in vitro y ex vitro de A. leiocarpa y la aclimatación de plántulas micropropagadas. La hipótesis fue que el tipo de explante, la concentración de ácido indolbutírico (IBA) y el sustrato influyen en la inducción de raíces adventicias en A. leiocarpa. Para el enraizamiento in vitro, se cultivaron segmentos nodales y microcortes en un Medio de Plantación de Árboles (Wood Plant Medium) (WPM) con 0, 4.9, 9.8, 14.7 y 19.6 μM de IBA. Para la aclimatización se probaron mezclas de sustrato comercial + vermiculita + arena gruesa y sustrato comercial + vermiculita, en proporciones iguales. Para el enraizamiento ex vitro, se trataron segmentos nodales y microcortes con 0 y 4920 μM de IBA durante 10 s y se cultivaron en proporciones iguales de: sustrato comercial + vermiculita + arena gruesa, sustrato comercial + vermiculita y sustrato comercial + arena gruesa. Los segmentos nodales presentaron mayor enraizamiento in vitro que los microcortes sin suplemento de IBA en el medio de cultivo. La composición del sustrato no afectó la supervivencia o el crecimiento de las plántulas enraizadas in vitro durante la aclimatación. El mejor enraizamiento ex vitro se encontró en segmentos nodales y explantes tratados con 4920 μM IBA y cultivados en sustrato comercial + vermiculita + arena gruesa. El enraizamiento ex vitro es una técnica prometedora para producir plántulas de apuleia; sin embargo, se necesitan ajustes a las condiciones ambientales, en el enraizamiento ex vitro y en la aclimatación para maximizar la supervivencia de las plántulas micropropagadas de A. leiocarpa.

RESUMO A técnica de microestaquia e enraizamento ex vitro pode resultar em mudas com o sistema radicular de melhor qualidade e com maior número de raízes secundárias, quando comparada com a estaquia convencional. O objetivo deste trabalho foi avaliar o enraizamento ex vitro e a aclimatização de microestacas de erva-mate em diferentes doses do fitorregulador ácido 3-indolibutírico (AIB) e substratos. Em sala de cultivo foi avaliada diferentes doses de ácido 3-indolibutírico (0, 250, 500, 1000 e 2000 mg.L-1) e diferentes substratos utilizados puros (areia grossa, casca de arroz carbonizada, vermiculita, fibra de coco e substrato comercial). Em câmara úmida foram avaliados os mesmos substratos utilizados puros e as seguintes composições de mesmas proporções de volume: casca de arroz carbonizada + areia grossa; casca de arroz carbonizada + areia grossa + substrato comercial; casca de arroz carbonizada + substrato comercial. O enraizamento e a aclimatização ex vitro de microestacas de erva-mate podem ser realizados em câmara úmida, sendo necessário o uso de ácido 3-indolibutírico na dose de até 1250 mg.L-1. O substrato composto em iguais proporções volumétricas de casca de arroz carbonizada + areia grossa + substrato comercial proporcionou uma maior porcentagem de microestacas enraizadas.

ABSTRACT The technique of microcutting and ex vitro rooting can result in plantlets with better quality of radicular system and larger number of secondary roots, when compared with conventional cutting. The objective of this work was to evaluate the ex vitro rooting and acclimatization of holly microcuttings in different doses of phytoregulator indole-3-butyric acid (IBA) and substrate. In the growth room were evaluated different doses of indole-3-butyric acid (0, 250, 500, 1000 and 2000 mg.L-1) and different substrates used pure (coarse sand, carbonized rice husk, vermiculite, coconut fiber and commercial substrate). In humid chamber were evaluated the same pure substrates and the following combinations of the same volume ratios: carbonized rice husk + coarse sand; carbonized rice husk + coarse sand + commercial substrate; carbonized rice husk + commercial substrate. The ex vitro rooting and acclimation of holly microcuttings can be done in the humid chamber, necessitating the use of indole-3-butyric acid at a dose of 1250 mg.L-1. The substrate composed in equal proportions of carbonized rice husk + coarse sand + commercial substrate provided a higher percentage of rooted microcuttings.

O objetivo, neste trabalho, foi estimar o impacto de cenários de temperaturas elevadas no desenvolvimento foliar da cultura da batata, em Santa Maria-RS, Brasil. A emissão de folhas da cultura da batata foi estimada por um modelo multiplicativo com função de reposta não linear à temperatura que calcula a taxa diária de aparecimento de folhas (TAF, folhas dia-1) e o número acumulado de folhas (NF) a partir da data de emergência da cultura até o surgimento da última folha. A emissão de folhas foi estimada em 100 anos de cada um dos cenários climáticos: clima atual, +1 °C, +2 °C, +3 °C, +4 °C e +5 °C. O modelo da TAF foi estimado com coeficientes da cultivar Asterix, em cinco datas de emergência e em duas estações de cultivo (Outono e Primavera). A variável de interesse foi duração (em dias) da fase de emergência das plântulas até o aparecimento da folha final (EM-FF). A análise estatística constou de um experimento trifatorial, com os fatores principais sendo cenários climáticos, estações de cultivo e datas de emergência no delineamento inteiramente casualizado, com anos (cem anos) como repetições. Observou-se que cenários mais quentes levam a um aumento, no cultivo de outono, e a uma diminuição, no cultivo de primavera, da duração da fase de emissão de folhas, indicando grande vulnerabilidade e complexidade da resposta da batata cultivada em ambiente Subtropical à mudança climática.

The objective of this study was to simulate the impact of elevated temperature scenarios on leaf development of potato in Santa Maria, RS, Brazil. Leaf appearance was estimated using a multiplicative model that has a non-linear temperature response function which calculates the daily leaf appearance rate (LAR, leaves day-1) and the accumulated number of leaves (LN) from crop emergence to the appearance of the upper last leaf. Leaf appearance was estimated during 100 years in the following scenarios: current climate, +1 °C, +2 °C, +3 °C, +4 °C e +5 °C. The LAR model was estimated with coefficients of the Asterix cultivar in five emergence dates and in two growing seasons (Fall and Spring). Variable of interest was the duration (days) of the crop emergence to the appearance of the final leaf number (EM-FLN) phase. Statistical analysis was performed assuming a three-factorial experiment, with main effects being climate scenarios, growing seasons, and emergence dates in a completely randomized design using years (one hundred) as replications. The results showed that warmer scenarios lead to an increase, in the fall, and a decrease, in the spring growing season, in the duration of the leaf appearance phase, indicating high vulnerability and complexity of the response of potato crop grown in a Subtropical environment to climate change.

Atoxicidade do alumínio é um problema sério em solos brasileiros e a seleção de clones de batata é uma estratégia importante para produzir essa cultura em tais solos. Clones de batata, Macaca, SMIC148-A, Dakota Rose e Solanum microdontum, foram cultivados em solução nutritiva (pH 4.0) com 0, 50, 100, 150 e 200 mg Al L-1. Após 7 d, o teor de Al em raízes e parte aérea em todos clones aumentou linearmente com o suprimento de Al. Baseado no crescimento relativo da raiz, os clones S. microdontum e SMIC148-A foram considerados tolerantes ao Al, enquanto os clones Macaca e Dakota Rose foram considerados sensíveis. O crescimento da parte aérea do clone Macaca diminuiu linearmente com o Al. A concentração de H2O2 nas raízes de ambos os clones sensíveis ao Al aumentou com o suprimento de Al, enquanto nos clones tolerantes houve decréscimo (SMIC148-A) ou falta de resposta (S. microdontum). A concentração de H2O2 na parte aérea aumentou linearmente em Macaca, enquanto em Dakota Rose houve uma relação quadrática com os níveis de Al. Por outro lado, nos clones tolerantes ao Al a concentração de H2O2 não foi alterada (S. microdontum) ou foi reduzida (SMIC148-A). A atividade da catalase (CAT) nas raízes de ambos clones sensíveis ao Al aumentou com o suprimento de Al, enquanto nos clones tolerantes não houve alteração (SMIC148-A) ou, então, redução (S. microdontum). Na parte aérea, a atividade da CAT em S. microdontum aumentou com o suprimento de Al. Em todos clones de batata, a concentração de clorofila variou curvilinearmente em relação ao suprimento de Al; nos clones sensíveis, a concentração de clorofila diminuiu pela adição de Al em níveis acima de 100 mg L-1, porém em SMIC148-A houve aumento na presença de Al (na faixa próxima a 100 e 150 mg L-1) e diminuição em S. microdontum, independentemente do tratamento de Al. A concentração de carotenóides nos clones sensíveis ao Al diminuiu linearmente, em resposta ao Al. O Al aumentou a peroxidação lipídica em raízes dos clones sensíveis, enquanto na parte aérea houve aumento linear nesses clones e também em S. microdontum (próximo a 50 mg Al L-1). A oxidação protéica foi observada principalmente nas raízes dos clones sensíveis ao alumínio. Entretanto, foi observada oxidação protéica na parte aérea de todos clones de batata, em resposta ao Al. Estes resultados indicam que o estresse oxidativo causado por Al em batata pode prejudicar vários componentes celulares, principalmente nos clones sensíveis ao metal.

Aluminum toxicity is a serious problem in Brazilian soils and selecting potato clones is an important strategy to produce this crop on these kinds of soils. Potato clones, Macaca, SMIC148-A, Dakota Rose, and Solanum microdontum, were grown in a nutrient solution (pH 4.0) with 0, 50, 100, 150 and 200 mg Al L-1. After 7 d, Al concentration in both root system and shoot of all clones increased linearly with increasing Al levels. Based on relative root growth, S. microdontum and SMIC148-A were considered Al-tolerant clones, whereas Macaca and Dakota Rose were considered Al-sensitive. Shoot growth in Macaca linearly decreased with increasing Al levels. Root H2O2 concentration in both Al-sensitive clones increased with increasing Al supply, whereas in Al-tolerant clones it either decreased (SMIC148-A) or demonstrated no alteration (S. microdontum). Shoot H2O2 concentration increased linearly in Macaca, whereas for Dakota Rose it showed a quadratic relationship with Al levels. On the other hand, shoot H2O2 concentration in the Al-tolerant clones either demonstrated no alteration (S. microdontum) or presented lower levels (SMIC148-A). Root catalase (CAT) activity in both Al-sensitive clones increased with increasing Al levels, whereas in Al-tolerant clones it either demonstrated no alteration (SMIC148-A) or presented lower levels (S. microdontum). Shoot CAT activity in the S. microdontum increased curvilinearly with increasing Al levels. In all potato clones, chlorophyll concentration showed a curvilinear response to Al supply, where in Al-sensitive clones it decreased upon addition of Al exceeding 100 mg L-1, but in SMIC148-A it increased at levels between approximately 100 and 150 mg L-1, and decreased in S. microdontum regardless of the Al level. Carotenoid concentrations in the Al-sensitive clones were linearly decreased with increasing Al levels. Aluminum supply caused root lipid peroxidation only in the Al-sensitive clones, whereas in the shoot it increased linearly in the Al-sensitive clones and in S. microdontum it only increased at around 50 mg L-1. Most of root protein oxidation was only observed in the Al-sensitive clones. However, shoot protein oxidation was increased with increasing Al levels for all potato clones. These results indicate that oxidative stress caused by Al in potato may harm several components of the cell, mainly in Al-sensitive clones.