Adenium obesum
seeds germinated and in vitro cultivated under lighting with different wavelengths of light from light emitting diodes (LEDs) (white LED—6400 K—λ = 525 nm; blue LED—λ = 430 nm; green ...LED—λ = 520 nm; orange LED—λ = 595 nm; purple LED—λ = 440 nm “2 blue LEDs + 1 red LED”; and red LED—λ = 670 nm) and control—absence of LED, combined with different culture media (MS and MRA). This work aimed to evaluate the influence of LED lighting conditions and culture media on seed germination, initial in vitro growth of
A. obesum
seedlings and production of photosynthetic pigments and soluble sugars. The study demonstrated a significant effect of red LED light combined with MRA medium and purple LED combined with MS medium, promoting the highest germination rates and the lowest mortality rates. The best initial in vitro development of
A. obesum
seedlings occurred under red LED in both culture media, which generated positive changes in the morphological variables analyzed. The highest pigment contents were obtained by combining white light with MS medium and green light with MRA medium. This is the first report to provide evidence of the stimulating effect of light quality on germination, early growth, production of photosynthetic pigments by
A. obesum
seedlings in vitro.
Key message
The influence of the culture media MS and MRA in combination or not with different LED colors in the stimulation of germination and production of photosynthetic pigments in plants of
Adenium
obesum
was proven.
Banana micropropagation allows the production of vigorous and high-quality phytosanitary plants, which can be improved with the use of endophytic growth-promoting bacteria (PGPB) that stimulate the ...growth and development of plants. It is possible to associate them with hydroponics, allowing a high supply of seedlings and reducing the production cycle. The objective was to evaluate the effect of PGPB in a floating hydroponic system in the acclimatization phase of banana. The cultivars studied were Prata Anã and BRS Princesa. The treatments evaluated were as follows: control (nutrient broth without bacteria); Bacillus cereus strain 1 (BC1); Bacillus cereus strain 2 (BC2); Bacillus thuringiensis (BT); Buttiauxella agrestis (BA). Total height, pseudostem diameter, root length, number of leaves, fresh root mass, pseudostem, leaf and leaf area, stomatal conductance, internal carbon concentration, photosynthesis rate, transpiration rate, leaf temperature and chlorophyll. Bacteria B. cereus strain 2 and B. agrestis in the cultivar Prata Anã and B. agrestis in BRS Princesa improved the acclimatization process of the seedlings in a floating hydroponic system. Stimulating plant growth, fresh weight and promoting root growth. The association of bacteria and hydroponics allowed the reduction of the seedling acclimatization period from 90 to 25 (Prata Anã) and 15 days (BRS Princesa).
Agriculture is a fundamental activity for human development. However, its sustainable practice is required to ensure the perpetuity of future resources. In this way, bacteria can benefit crops by ...making available nutrients and metabolites, mainly contributing to reducing the demand for chemical fertilizers. This study aimed to evaluate the biofertilizing capacity of Azospirillum brasilense, Bacillus megaterium, and Brevibacillus fluminis and their effects on improving the physiological and morphoanatomical properties of strawberry seedlings. In vitro tests were performed to evince their potential to supply nutrients (P and K) and produce siderophores and indole-acetic acid. In an inoculation experiment, these strains were inoculated in isolation and mixed in pairs and triples. This experiment was carried out in a greenhouse in a completely randomized design (CRD). The inoculated treatments were fertilized with 30% N and P demands; the uninoculated control received 30% and 100% of these demands. Leaf gas exchange, total chlorophylls, and crown diameter were evaluated during cultivation. After 138 days, leaf number, nutrient content, root length, root and shoot fresh and dry weight, and total seedlings were evaluated. The bacteria tested positive in all in vitro evaluations except for siderophore production. The strawberry responded positively to inoculation. The inoculation, either in isolation or in a mixture, improved stomatal conductance, leaf transpiration, internal CO2 concentration, leaf N and Mg contents, crown diameter, leaf area, and root elongation. We can conclude that the intermediation of microorganisms improves nutrient use efficiency and reduces the strawberry’s fertilizer demand by up to 70%, leading to plant development and yields comparable to complete fertilization.
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.
•Vegetation indices can be used to estimate lettuce growth.•UAV image data showed more accuracy than field data in measuring lettuce growth.•Vegetation indices can be applied to detect diseases that ...affect lettuce growth.•Vegetation index values from RGB images should not be compared between flights.
Lettuce (Lactuca sativa) is an important horticultural commodity all over the world, and its growth can be affected by root-knot nematodes (Meloidogyne spp.). To keep track of plant behaviors, growers are using new technologies. In this paper, aerial images were obtained using a low-cost unmanned aerial vehicle (UAV) to gather crop information in a short time giving acceptable accuracy for decision-making in the field. Evaluations were done to check the flight height interference in the image's quality for lettuce mapping, and select the best one to estimate the effect of root-knot nematode incidence on lettuce growth. In a field infested with M. incognita, lettuce seedlings were planted in plots treated with bionematicide and control plots. Aerial images were obtained using low-cost UAV in four flight heights performed for five weeks, along with field measurements. Images were processed and used to calculate vegetation indices (VI) and vegetation cover (VC). After lettuce harvesting, nematode eggs were extracted from plants' roots and quantified. Plots treated with bionematicide showed no difference from the control plots in eggs number and lettuce growth. Differences in VI values between the flight heights were not consistent, suggesting that VI values could be affected by the lack of luminosity calibration in each flight condition. VC values calculated from field data presented strong positive correlations with VI and VC values from UAV image data, indicating that RGB images obtained by UAV can be used in the detection of diseases that affect plant growth, as well as following up harvesting time.
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
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.
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 Pyrus comunnis rootstocks, clones 'OHxF87' and Pyrodwarf. Explant exposure times (0, 24, 48, 72, and 96 hours) to 20 mg L.sup.-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.sup.-1 IBA was sufficient to promote in vitro rooting in 'OHxF87' and Pyrodwarf rootstocks'. Key words: 'OHxF87', 'PDW', plant tissue culture, Pyrodwarf, seedling production, 6-Benzylaminopurine. Protocolos eficazes de enraizamento in vitro de frutiferas lenhosas ainda sao um desafio para producao de mudas in vitro, especialmente quando ha necessidade de insercao de novas cultivares ou porta-enxerto. Esses protocolos sao essenciais para acelerar estudos nos programas de melhoramento genetico e tambem para distribuicao posterior das mudas. Nesse sentido, o objetivo deste estudo foi avaliar a utilizacao da 6-Benzilaminopurina no enraizamento in vitro de porta-enxerto Pirus comunnis, clones 'OHxF87' e Pyrodwarf. Para o enraizamento, foi testado o tempo de exposicao dos explantes ao AIB. Para tanto, foram utilizados 20 mg L.sup.-1 do fitohormonio nas horas 0, 24, 48, 72 e 96 horas. A exposicao 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 sobrevivencia, promovendo em media cinco raizes com comprimento de 19 mm. O mesmo tratamento para o porta-enxerto 'PDW' resultou na maior taxa de sobrevivencia (75%), bem como no maior numero medio de raizes, sete raizes por planta, com comprimento de 10 mm. Na ausencia de auxina sintetica, a formacao de raizes nao ocorreu. Assim sendo, podemos concluir que o tempo de exposicao de 24 horas a 20 mg L.sup.-1 de IBA foi suficiente para promover o enraizamento de porta-enxertos Pyrus communis de 'OHxF87' e 'PDW'. Palavras-chave: cultura de tecidos vegetais, OHxF87, PDW, Pyrodwarf; Producao de mudas, 6-Benzylaminopurine.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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