Padronização de um protocolo para assepsia de segmentos nodais de Phalaenopsispara clonagem in vitro / Standardization of a protocol for assepsis of nodal Phalaenopsissegments for in vitrocloning

A biotecnologia vegetal é uma área de elevada importância, uma vez que tem a função de obter organismos vegetais com características superiores aos já existentes no mercado. A clonagem é uma das ferramentas que podem ser utilizadas para essa função, através dela, seleciona-se organismos com características de interesse e realiza-se a multiplicação deste individuo, garantindo que as plantas regeneradas sejam geneticamente idênticas a matriz desejada, estabelecendo uma padronização. Sabendo que o setor de plantas ornamentais contribui de maneira expressiva com a economia e dentre as plantas ornamentais de mais estima entre os brasileiros, encontram-se as orquídeas, que vem adquirindo visibilidade cultural e um grande número de colecionadores nos últimos anos. O objetivo, do presente trabalho, foi estabelecer um protocolo de assepsia eficiente para meristemas laterais e obtenção de clones da orquídea do gênero Phalaenopsis. Para metodologia, visando a padronização de um protocolo de assepsia, foram elaborados e testados 4 tratamentos que possuíam diferentes combinações (concentração x tempo) de agentes como o hipoclorito de sódio, álcool, cobre, tween e lavagem dos explantes com água destilada estéril para meristemas laterais da orquídea de gênero Phalaenopsis. Os meristemas, também conhecidos como gemas laterais, foram retirados do caule das plântulas, de suas hastes florais...(AU)

Plant biotechnology is an área of high importance since it has the function of obtaining plant organisms with characteristics superior to those already on the market. Cloning is one of the tools that can be used for this function, through it, organisms with characteristics of interest are selected and this individual is multiplied, ensuring that the regenerated plants are genetically identical to the desired matrix, establishing a standardization. Knowing that the ornamental plants sector contributes significantly to the economy and among the most esteemed ornamental plants among Brazilians, there are orchids which have acquired cultural visibility and a large number of collectors in recent years.  The objective of the present work was to establish an efficient assepsis protocol for lateral meristems and to obtain clones of the orchid of the genus Phalaenopsis. For methodology, aiming at the standardization o fan asepsis protocol, 4 treatments were developed and tested with different combinations (concentration x time) of agents such as sodium hypochlorite, alcohol, copper, tween and washing the explants with sterile distilled wáter for meristems of the orchid of the genus Phalaenopsis. The meristems, also known as lateral buds, were removed from the stem of the seedlings, from their floral stems. As for obtained clones, the experiment carried out consisted of...(AU)

Padronização de um protocolo para assepsia de segmentos nodais de Phalaenopsispara clonagem in vitro / Standardization of a protocol for assepsis of nodal Phalaenopsissegments for in vitrocloning

A biotecnologia vegetal é uma área de elevada importância, uma vez que tem a função de obter organismos vegetais com características superiores aos já existentes no mercado. A clonagem é uma das ferramentas que podem ser utilizadas para essa função, através dela, seleciona-se organismos com características de interesse e realiza-se a multiplicação deste individuo, garantindo que as plantas regeneradas sejam geneticamente idênticas a matriz desejada, estabelecendo uma padronização. Sabendo que o setor de plantas ornamentais contribui de maneira expressiva com a economia e dentre as plantas ornamentais de mais estima entre os brasileiros, encontram-se as orquídeas, que vem adquirindo visibilidade cultural e um grande número de colecionadores nos últimos anos. O objetivo, do presente trabalho, foi estabelecer um protocolo de assepsia eficiente para meristemas laterais e obtenção de clones da orquídea do gênero Phalaenopsis. Para metodologia, visando a padronização de um protocolo de assepsia, foram elaborados e testados 4 tratamentos que possuíam diferentes combinações (concentração x tempo) de agentes como o hipoclorito de sódio, álcool, cobre, tween e lavagem dos explantes com água destilada estéril para meristemas laterais da orquídea de gênero Phalaenopsis. Os meristemas, também conhecidos como gemas laterais, foram retirados do caule das plântulas, de suas hastes florais...

Plant biotechnology is an área of high importance since it has the function of obtaining plant organisms with characteristics superior to those already on the market. Cloning is one of the tools that can be used for this function, through it, organisms with characteristics of interest are selected and this individual is multiplied, ensuring that the regenerated plants are genetically identical to the desired matrix, establishing a standardization. Knowing that the ornamental plants sector contributes significantly to the economy and among the most esteemed ornamental plants among Brazilians, there are orchids which have acquired cultural visibility and a large number of collectors in recent years.  The objective of the present work was to establish an efficient assepsis protocol for lateral meristems and to obtain clones of the orchid of the genus Phalaenopsis. For methodology, aiming at the standardization o fan asepsis protocol, 4 treatments were developed and tested with different combinations (concentration x time) of agents such as sodium hypochlorite, alcohol, copper, tween and washing the explants with sterile distilled wáter for meristems of the orchid of the genus Phalaenopsis. The meristems, also known as lateral buds, were removed from the stem of the seedlings, from their floral stems. As for obtained clones, the experiment carried out consisted of...

Class I KNOX Is Related to Determinacy during the Leaf Development of the Fern Mickelia scandens (Dryopteridaceae).

Unlike seed plants, ferns leaves are considered to be structures with delayed determinacy, with a leaf apical meristem similar to the shoot apical meristems. To better understand the meristematic organization during leaf development and determinacy control, we analyzed the cell divisions and expression of Class I KNOX genes in Mickelia scandens, a fern that produces larger leaves with more pinnae in its climbing form than in its terrestrial form. We performed anatomical, in situ hybridization, and qRT-PCR experiments with histone H4 (cell division marker) and Class I KNOX genes. We found that Class I KNOX genes are expressed in shoot apical meristems, leaf apical meristems, and pinnae primordia. During early development, cell divisions occur in the most distal regions of the analyzed structures, including pinnae, and are not restricted to apical cells. Fern leaves and pinnae bear apical meristems that may partially act as indeterminate shoots, supporting the hypothesis of homology between shoots and leaves. Class I KNOX expression is correlated with indeterminacy in the apex and leaf of ferns, suggesting a conserved function for these genes in euphyllophytes with compound leaves.

Leaf ontogeny of Schinus molle L. plants under cadmium contamination: the meristematic origin of leaf structural changes.

Previous works show the development of thicker leaves on tolerant plants growing under cadmium (Cd2+) contamination. The aim of this study was to evaluate the Cd2+ effects on the leaf meristems of the tolerant species Schinus molle. Plants were grown in nutrient solution containing 0, 10, and 50 µM of Cd2+. Anatomical analysis was performed on leaf primordia sampled at regular time intervals. Under the lowest Cd2+ level (10 µM), increased ground meristem thickness, diameter of the cells, cell elongation rate, and leaf dry mass were found. However, 50 µM of Cd2+ reduced all these variables. In addition, the ground meristem cells became larger when exposed to any Cd2+ level. The epidermis, palisade parenchyma, and vascular tissues developed earlier in Cd2+-exposed leaves. The modifications found on the ground meristem may be related to the development of thicker leaves on S. molle plants exposed to low Cd2+ levels. Furthermore, older leaves showed higher Cd2+ content when compared to the younger ones, preventing the Cd2+ toxicity to these leaves. Thus, low Cd2+ concentrations change the ground meristem structure and function reflecting on the development of thicker and enhanced leaves.

Morphology, secretion composition, and ecological aspects of stipular colleters in Rubiaceae species from tropical forest and savanna.

Colleters are secretory structures that produce and release mucilage or a mucilage-resin mixture protecting meristems and young structures against desiccation, herbivores, and pathogens. The secretions may vary in colleters of same or different types, indicating that the functionality of colleters may be more specific than previously thought. In this study, we compared 17 Rubiaceae species from savanna and forest environment focusing on colleter secretions and its ecological role. First, we evaluated the morphology, distribution, and histochemistry of stipular colleters using light and scanning electron microscopy. Additionally, we investigated the phenology, microclimate, and the proportion of damaged apices in the savanna and forest species. We recorded standard-type colleters, variable in distribution and size, in 14 of the 17 studied species. The secretion varied from predominantly hydrophilic, mixed to predominantly lipophilic. During the budding period, secretion covered the vegetative apices. Savanna species had a prevalence of lipid secretion in habitats with higher luminosity, which had a lower proportion of damaged apices. In contrast, forest species occurred in habitats with lower luminosity and had a higher proportion of damaged apices, in general with the absence of lipids in the colleters. These results highlight that colleters with similar morphology clearly differed in secretions among species, especially between species from savanna and forest, in which the colleters appear potentially associated with protection against irradiation in savanna, but not in the forest environment.

Estabelecimento de pereira (Pyrus spp.) in vitro a partir de meristemas e gemas

The work had the purpose to determine the best type of explant and its best time of collection aiming to establish the in vitro culture for pear. In the first trial, pear buds and meristems from Carrick and Garber cultivars were isolated 28 days after the beginning of mother plants shooting. In the second trial, meristems from Carrick, Garber and Smith pear cultivars were isolated at 28, 35, 42, 49 and 56 days after shooting. The culture medium used was the MS salts added with BAP (4.44muM), NAA (0.05muM) and GA3 (0.29muM). After the inoculation the explants were subjected to a dark room for four days at temperature 25 ± 2ºC and then transferred to a growth room in a 16 - hour photoperiod, 25µmo IMG SRC="http:/img/fbpe/cr/v32n4/a05img01.gif">es.m-2.s-1 radiation and at 25 ± 2ºC. It could be concluded that: (i) for the in vitro establishment of the Carrick cultivar buds and meristems could be used, although for Garber cv., meristem is the best explant; and (ii) the time of meristem isolation showed a linear behavior to establish percentage achieving 92.9% for the meristems collected at 56 days after shooting.

O trabalho objetivou determinar o melhor tipo de explante e a melhor época de coleta destes, visando ao estabelecimento de cultivo in vitro da pereira. No experimento I, gemas e meristemas de pereira das cultivares Carrick e Garber foram isoladas 28 dias após o início da brotação das plantas matrizes. No experimento II, meristemas das cultivares Carrick, Garber e Smith foram isolados aos 28, 35, 42, 49 e 56 dias após o início da brotação. O meio de cultura utilizado foi o MS, acrescido de BAP (4,44miM), ANA (0,054miM) e AG3 (0,29miM). Após a inoculação, os explantes foram submetidos ao escuro sob temperatura de 25 ± 2ºC por um período de 4 dias e, em seguida, transferidos para sala de crescimento com 16 horas de fotoperíodo com radiação de 25µmo IMG SRC="http:/img/fbpe/cr/v32n4/a05img01.gif">es.m-2.s-1 e temperatura de 25 ± 2ºC. Os resultados permitiram concluir que, para o estabelecimento in vitro da cultivar Carrick, foi possível a utilização de gemas ou meristemas. Já para a cultivar Garber, o melhor explante foi o meristema; as épocas de isolamento dos meristemas mostraram comportamento linear para a percentagem de estabelecimento, obtendo-se 92,9% de estabelecimento nos meristemas isolados aos 56 dias após o início da brotação.

Estabelecimento de pereira (Pyrus spp.) in vitro a partir de meristemas e gemas

The work had the purpose to determine the best type of explant and its best time of collection aiming to establish the in vitro culture for pear. In the first trial, pear buds and meristems from Carrick and Garber cultivars were isolated 28 days after the beginning of mother plants shooting. In the second trial, meristems from Carrick, Garber and Smith pear cultivars were isolated at 28, 35, 42, 49 and 56 days after shooting. The culture medium used was the MS salts added with BAP (4.44muM), NAA (0.05muM) and GA3 (0.29muM). After the inoculation the explants were subjected to a dark room for four days at temperature 25 ± 2ºC and then transferred to a growth room in a 16 - hour photoperiod, 25µmo IMG SRC="http:/img/fbpe/cr/v32n4/a05img01.gif">es.m-2.s-1 radiation and at 25 ± 2ºC. It could be concluded that: (i) for the in vitro establishment of the Carrick cultivar buds and meristems could be used, although for Garber cv., meristem is the best explant; and (ii) the time of meristem isolation showed a linear behavior to establish percentage achieving 92.9% for the meristems collected at 56 days after shooting.

O trabalho objetivou determinar o melhor tipo de explante e a melhor época de coleta destes, visando ao estabelecimento de cultivo in vitro da pereira. No experimento I, gemas e meristemas de pereira das cultivares Carrick e Garber foram isoladas 28 dias após o início da brotação das plantas matrizes. No experimento II, meristemas das cultivares Carrick, Garber e Smith foram isolados aos 28, 35, 42, 49 e 56 dias após o início da brotação. O meio de cultura utilizado foi o MS, acrescido de BAP (4,44miM), ANA (0,054miM) e AG3 (0,29miM). Após a inoculação, os explantes foram submetidos ao escuro sob temperatura de 25 ± 2ºC por um período de 4 dias e, em seguida, transferidos para sala de crescimento com 16 horas de fotoperíodo com radiação de 25µmo IMG SRC="http:/img/fbpe/cr/v32n4/a05img01.gif">es.m-2.s-1 e temperatura de 25 ± 2ºC. Os resultados permitiram concluir que, para o estabelecimento in vitro da cultivar Carrick, foi possível a utilização de gemas ou meristemas. Já para a cultivar Garber, o melhor explante foi o meristema; as épocas de isolamento dos meristemas mostraram comportamento linear para a percentagem de estabelecimento, obtendo-se 92,9% de estabelecimento nos meristemas isolados aos 56 dias após o início da brotação.