Effective protocols for in vitro rooting for woody fruit trees are still a challenge for in vitro seedling production, especially when there is a need to insert new cultivars or rootstocks. These ...protocols are essential to accelerate studies in plant breeding programs and for seedling distribution. This study evaluated the use of 6-Benzylaminopurine (IBA) in in vitro rooting of Pyruscomunnis rootstocks, clones ‘OHxF87’ and Pyrodwarf. Explant exposure times (0, 24, 48, 72, and 96 hours) to 20 mg L-1 IBA were tested for in vitro rooting. The exposure to IBA resulted in rooting rates above 80%, surpassing some results reported in the literature. The 24-hour treatment provided 81,81% survival, leading to an average growth of five roots with 19 mm length, for ‘OHxF87’ rootstock. The same exposure time resulted in the highest survival rate (75%) and the highest mean root number, seven roots per plant with 10 mm length, for ‘PDW’ rootstock. Root formation did not occur in the absence of synthetic auxin. Therefore, it can be concluded that a 24-hour exposure at 20 mg L-1 IBA was sufficient to promote in vitro rooting in ‘OHxF87’ and Pyrodwarf rootstocks’.
RESUMO: Protocolos eficazes de enraizamento in vitro de frutíferas lenhosas ainda são um desafio para produção de mudas in vitro, especialmente quando há necessidade de inserção de novas cultivares ou porta-enxerto. Esses protocolos são essenciais para acelerar estudos nos programas de melhoramento genético e também para distribuição posterior das mudas. Nesse sentido, o objetivo deste estudo foi avaliar a utilização da 6-Benzilaminopurina no enraizamento in vitro de porta-enxerto Pirus comunnis, clones ‘OHxF87’ e Pyrodwarf. Para o enraizamento, foi testado o tempo de exposição dos explantes ao AIB. Para tanto, foram utilizados 20 mg L-1 do fitohormônio nas horas 0, 24, 48, 72 e 96 horas. A exposição ao AIB resultou em taxas de enraizamento acima de 80%, superando alguns resultados encontrados na literatura. Para o porta-enxerto ‘OHxF87’, o tratamento de 24 horas proporcionou 81,81% de sobrevivência, promovendo em média cinco raízes com comprimento de 19 mm. O mesmo tratamento para o porta-enxerto ‘PDW’ resultou na maior taxa de sobrevivência (75%), bem como no maior número médio de raízes, sete raízes por planta, com comprimento de 10 mm. Na ausência de auxina sintética, a formação de raízes não ocorreu. Assim sendo, podemos concluir que o tempo de exposição de 24 horas a 20 mg L-1 de IBA foi suficiente para promover o enraizamento de porta-enxertos Pyrus communis de ‘OHxF87’ e ‘PDW’.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract With the occurrence of the COVID-19 pandemic, different areas were affected, with positive or negative effects, as a function of the conditions imposed above all by gardening activities. ...This brought effects on the production of ornamental plants. In this context, the objective of this study was to analyse the situation of production, commercialization and the impact of the COVID-19 pandemic on the ornamental plants market in the city of Dona Euzébia-MG. A questionnaire with objective and discursive questions was applied to the city producers (30). The production of seedlings in Dona Euzébia is economically and socially important. Most producers have properties with 5 hectares, are in activity for a range of 5 to 19 years and have between 2 to 5 employees. With the onset of the pandemic, the market for seedlings and ornamental plants in Dona Euzébia was positively modified, with an increase in plant sales, which led to changes in production and in the sales process. During the period, producers took all measures to prevent the spread of the virus. The interviews showed that ornamental plants were among the main species cultivated and among the most sought during the pandemic period analyzed in this study. Furthermore, despite the restrictions and the uncertain scenario, there is optimism among producers, especially in terms of post-pandemic sales.
Resumo Com o surgimento da pandemia do COVID-19 os mercados das mais diferentes áreas foram atingidos, positivamente ou negativamente. Neste sentido, o objetivo deste trabalho foi analisar a situação de produção, comercialização e o impacto da pandemia do COVID-19 sobre o mercado de plantas ornamentais da cidade de Dona Euzébia-MG. Diante disto um questionário com perguntas objetivas e discursivas, foi aplicado aos (30) produtores da cidade. A maioria dos produtores possui propriedades com 5 hectares, estão em atividade no intervalo de 5 a 19 anos e possuem entre 2 a 5 funcionários. Com o surgimento da pandemia, o mercado de mudas e plantas ornamentais em Dona Euzébia foi modificado positivamente, sendo relatado o aumento na comercialização de plantas, o que gerou alterações na produção e no processo de vendas. Durante o período, os produtores adotaram todas as medidas de prevenção contra a disseminação do vírus. As entrevistas mostraram que as plantas ornamentais estavam entre as principais espécies cultivadas e entre as mais procuradas durante o período de pandemia em que este trabalho analisou. Além disso, apesar das restrições e do cenário de incertezas, há um otimismo dos produtores do município especialmente nas vendas pós pandemia.
Abstract The use of agricultural residues as a substrate is a promising option for orchid acclimatization, which is a critical stage of micropropagation. Thus, this study aimed to evaluate the use of ...grape residue S-10 Beifort®, isolated or mixed with other agricultural residues, in the acclimatization of Oncidium baueri Lindl. Five treatments were studied (S-10 Beifort®; S-10 Beifort® + carbonized rice husk (CRH); S-10 Beifort® + coconut fiber (CF); S-10 Beifort® + CRH + CF; CRH + CF), with four replications containing 10 seedlings each. After 120 days, the highest survival rate occurred with the mixture CRH + CF (62.5%). The mixture of S-10 Beifort® with CRH provided a greater shoot length (3.7 cm), not differing from the mixture of the three substrates (2.9 cm). S-10 Beifort® + CRH and the mixture of the three substrates ensured greater root length (3.8 cm). The mixture of the three residues provided the highest average of fresh and dry mass accumulation. The pH variation between the substrates was from 5.2 to 6.3, while S-10 Beifort® presented the highest electrical conductivity (2030 μS cm-1) and the mixture of this material with carbonized rice husk presented the highest water retention capacity. The use of a mixture of S-10 Beifort® with carbonized rice husk or with carbonized rice husk and coconut fiber (1:1:1) is indicated for the acclimatization of Oncidium baueri Lindl.
Resumo Na aclimatização os substratos podem contribuem para a adaptação vegetal após o cultivo in vitro. Este trabalho teve como objetivo avaliar o uso de S-10 Beifort®, um resíduo agrícola à base de uva, isolado ou em misturas com outros resíduos agrícolas na aclimatização de Oncidium baueri Lindl. Os substratos foram S-10 Beifort®, e as misturas de S-10 Beifort® com Casca de Arroz Carbonizada, Fibra de Coco, e Casca de Arroz Carbonizada + Fibra de Coco. Foi utilizado delineamento experimental inteiramente casualizado, com cinco tratamentos e quatro repetições, contendo 10 plântulas cada. Após 120 dias a maior taxa de sobrevivência ocorreu com a mistura de Casca de Arroz Carbonizada e Fibra de Coco (62,5%). A mistura de S-10 Beifort® com a Casca de Arroz Carbonizada propiciou maior comprimento de parte aérea das plantas (3,7 cm), não diferindo apenas da mistura dos três substratos juntos (2,9 cm). Estas misturas garantiram maior comprimento de raiz (3,8 cm). A mistura dos três resíduos propiciou maior acúmulo de massa fresca e seca para plantas. A variação de pH entre os substratos foi de 5,2 a 6,3. O S-10 Beifort® apresentou a maior condutividade elétrica (2030 μS cm-1). Além disso, o substrato S-10 Beifort® em mistura com Casca de Arroz Carbonizada, apresentou a maior taxa de retenção de água. Podemos concluir que o uso da mistura de S-10 Beifort® com Casca de Arroz Carbonizada e com a Fibra de Coco (1:1:1) é indicado para a aclimatização de Oncidium baueri Lindl.
This study aimed to investigate the presence of beneficial microorganisms in the micropropagation of Pyrus communis rootstocks through the isolation, identification, and selection of auxin-producing ...bacteria. The selected microorganisms were also inoculated in vitro to evaluate their effect on the plant rooting process and their behavior during the acclimatization phase. The results showed the presence of endophytic microorganisms in plant tissue cultures of the ‘OH×F87′ and ‘PDW’ selections. A low diversity was observed in the population of microorganisms isolated from the in vitro culture of the ‘OH×F87’and ‘PDW’ selections, with a predominance of the genera Acinetobacter, Bacillus, and Buttiauxella. The selection of promoting microorganisms was performed based on the auxin production test, in which 30.36% of the microorganisms tested positive. In the in vitro inoculation, it was possible to observe the promotion of growth and emission of roots in the pear rootstocks, from the inoculation with bacteria identified as capable of producing auxin. This process can be used to replace the inclusion of synthetic auxin in the productive chain of woody fruit trees propagated by vegetative means, such as pears. None of the bacterial isolates was notably more promising, but the general similarity of treatments containing the A. septicus and A. ursingii strains, with the synthetic auxin treatment, suggests the possibility of its use on a large scale allowing the adoption of the cheaper method. of rooting. This work opens the door for further research using new, more promising microbial isolates, and also for lower-cost microorganism cultivation techniques, such as low-cost media obtained from agro-industrial residues.
The objective of the research was to evaluate cytokinin concentrations and agricultural residues as physical structuring agents of the culture medium in the in vitro propagation of highbush blueberry ...(Vaccinium corymbosum ‘Duke’). To that end, three different concentrations of 2-isopentenyladenine (2iP) (0, 5, and 10 mg L-1)in woody plant medium (WPM) and five structuring agents (in natura rice husks, carbonized rice husks, coconut fiber, S-10 Beifort®, and agar)were tested. After 60days of culture, the following parameters were evaluated: survival (%),sprout and shoot lengths (cm),propagation rate, number of sprouts, and shoot dry mass (g). The substrates used as structuring agents were analyzed in terms of pH and electrical conductivity. The in natura rice husk, S-10 Beifort®, and carbonized rice husk did not differ from the agar in terms of the sprout length. The shoots were longer (1.64 cm) in cultures within natura rice husk than in other treatments. In the absence of 2iP, S-10 Beifort® resulted in the highest propagation rate (2.97). Concerning the number of sprouts, S-10 Beifort®, in natura rice husks, and carbonized rice husks did not differ from agar. However, when the regulator was added, the agar performed better in comparison to the other residues. Thus, in natura rice husks, carbonized rice husks, and S-10 Beifort®are potential physical structuring agents of the culture medium that can be used without 2iP.
RESUMO: O objetivo deste trabalho foi avaliar concentrações de citocinina e resíduos agrícolas como agentes físicos de estruturação do meio na multiplicação in vitro de mirtileiro (Vaccinium corymbosum) ‘Duke’. Para isso, foram testadas três concentrações de 2-isopenteniladenina (2iP) (0; 5 e 10 mg L-1) no meio WPM (Wood Plant Media); e cinco agentes estruturantes (casca de arroz in natura, casca de arroz carbonizada, fibra de coco, S-10 Beifort® e ágar). Após 60 dias foram avaliados: sobrevivência (%); comprimento de brotações e de parte aérea (cm); taxa de multiplicação; número de brotações e massa seca de parte aérea (g). Analisou-se os substratos utilizados como agentes estruturantes quanto ao pH e condutividade elétrica. A casca de arroz in natura, o S-10 Beifort®, e a casca de arroz carbonizada não diferiram do ágar quanto ao comprimento de brotações. Na casca de arroz in natura obteve-se o maior comprimento de parte aérea (1,64 cm), diferindo dos demais tratamentos. Na ausência de 2iP o S-10 Beifort® apresentou a maior taxa de multiplicação (2,97). Para o número de brotações o S-10 Beifort®, a casca de arroz in natura e carbonizada não diferiram do ágar. Entretanto, quando acrescido de regulador, o ágar apresenta um desempenho maior em relação aos resíduos. Sendo assim, a casca de arroz in natura, a casca de arroz carbonizada, e o S-10 Beifort® apresentam-se como potencias estruturadores físicos do meio de cultura, podendo ser utilizados sem o uso de 2iP.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
An adequate concentration of growth regulators as well as the replacement of agar by an alternative medium may be promising from practical and financial points of view to produce orchid plants by ...micropropagation. The objective of this work was to evaluate different concentrations of growth regulator and alternative substrates for agar replacement in culture medium for in vitro multiplication and rooting of Oncidium baueri. In the explant multiplication phase, two experimental factors were evaluated- various concentrations of 6-benzylaminopurine (BAP) (0.0, 1.0, 2.0, and 3.0 mg L-1) and substrates (agar, vermiculite, and coconut fiber) added to MS medium. In the rooting phase, different concentrations of indole butyric acid (IBA) (0.0, 0.5, 1.0, and 1.5 mg L-1) were added to culture medium containing the same substrate. Six months after the experiments were initiated, the survival percentage, number of leaves, shoots, and roots and length of the aerial part and the major root were evaluated. The results suggested that addition of 1.0 mg L-1 BAP is necessary for the O. baueri in vitro multiplication phase, but IBA is not necessary in the rooting phase. For the substrate, vermiculite is not indicated as an agar replacement. In contrast, coconut fiber can be used in both multiplication and rooting phases of Oncidium baueri in vitro culture.
Strawberry is a pseudofruit of great economic importance, and most of its production is carried out in a conventional system. However, abiotic stresses can affect the culture. Salt stress is one of ...the problems that can cause damage, and consequently impair the growth and productivity of the crop. Therefore, the objective of this study was to evaluate the influence of growth-promoting bacteria in mitigating the morphological effect of salt stress caused by NaCl in strawberry. The experiment consisted of six treatments, two controls (0 and saline) and four containing the bacteria (
Pseudomonas fluorescens
,
Streptomyces
sp.,
Rhizobium
sp.,
Enterobacter
sp.) plus 50 mM NaCl. Strawberry plants of cultivars Pircinque and PRA Estiva were inoculated with the bacteria and transferred to 2L pots containing commercial substrate plus 50 mM NaCl, where they remained for 90 days. Subsequently, aerial part and root length, number of leaves, fresh and dry mass, chlorophyll
a
,
b
, total and carotenoids were evaluated. The bacterium Streptomyces sp. stood out positively in all phytotechnical parameters analyzed. For the cultivar Pircinque, in terms of pigment content, the microorganism
Enterobacter
sp. stood out among all the others for all the analyzed pigments, while for the cultivar PRA Estiva there was a greater emphasis on the microorganism Rhizobium sp. in all analyzed pigments. The growth-promoting bacteria mitigated the effects of salinity on strawberry plants, making their growth and photosynthetic production not compromised by NaCl toxicity.
The association of different species of endophytic bacteria with the rhizosphere of the host plants can stimulate growth, development and acclimatization, offering a greater quantity of seedlings, in ...addition to reducing the cycle, providing economic return to the producer. The objective of this study was to evaluate the effect of introduction four bacterial isolates through inoculation into the root system in three banana cultivars (Prata Anã, Grande Naine and BRS Princesa) in the acclimatization phase. The evaluated treatments were: control (nutrient broth without bacteria); Bacillus cereus strain 1 (BC1); Bacillus cereus strain 2 (BC2); Bacillus thuringiensis (BT); Buttiauxella agrestis (BA). The morphological characteristics related to the development of the plants (total height and pseudostem diameter) were evaluated throughout the acclimatization period. After 90 days of transplanting and acclimatization, root length, leaf number, dry root weight, pseudostem and leaf, leaf area, internal carbon concentration, stomatal conductance, photosynthesis rate, transpiration rate, leaf temperature and chlorophyll were evaluated.
The bacteria showed different results in relation to the studied cultivars. Considering the morphological and physiological characteristics observed in this study, B. thuringiensis for the cultivars Prata Anã and Grande Naine and the B. agrestis for the cultivar BRS Princesa are recommended for the process of acclimatization of banana seedlings, as they stimulated growth of the plant, increasing the dry mass, besides promoting the growth of roots. In this way, they improved the physiological aspects of the plants and reduced the period of acclimatization of the banana.
This study investigated the in vitro use of humic and fulvic acids to enhance salt stress tolerance in strawberry plants. The concentration of 37.5 mM NaCl induced stress in the plants, resulting in ...reduced growth. An enhancement in the antioxidant system was observed at higher concentrations of humic acid (15 mg L
−1
), with a similar pattern for fulvic acid, indicating an increase in these enzymes at higher concentrations (15 mg L
−1
) and a decrease at lower concentrations (5 mg L
−1
). Concentrations of 5 mg L
−1
and 15 mg L
−1
of humic acid led to an increase in chlorophyll
a
, while fulvic acid treatments showed an increase in chlorophyll
b
and total chlorophyll at higher concentrations (15 mg L
−1
). Regarding macronutrients and micronutrients, groups treated with humic and fulvic acids exhibited significant differences, with higher accumulations in control groups. In summary, humic and fulvic acids incorporated in vitro demonstrated the potential to induce the development of salt-tolerant strawberry plants, promoting reinforcement in the defense system, chlorophyll accumulation, and nutrient absorption. These findings suggest a promising approach to address the challenges of salt stress in strawberry plants.
Key Message
The use of humic and fulvic acids increased the activity of the plant defense system in response to NaCl. Therefore, plants developed in vitro in the presence of acids respond to abiotic stress more quickly.
Graphical abstract
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