Growth regulators, DNA content and anatomy in vitro-cultivated Curcuma longa seedlings

Curcuma longa L., from the Zingiberaceae family, generally reproduces through its rhizomes, which are also utilized for therapeutic purposes because they are rich in terpenoids. Its conventional propagation has low efficiency due to the small number of seedlings and their contamination by pathogens. Therefore, this study aimed to evaluate the influence of growth regulators on the development of in vitro-cultivated C. longa as well as to determine their influence on DNA content and foliar anatomy. Shoots were inoculated in MS culture medium with the addition of 30 g/L of sucrose and 6.5 g/L of agar, and a pH adjusted to 5.8. Two assays were built to study the multiplication and rooting phases of growth. The first assay evaluated the influence of eight concentrations of cytokinins and auxins on the multiplication phase. Leaf samples were analyzed for DNA content through flow cytometry, utilizing two reference standards, green pea, and tomato. Characteristics of leaf anatomy were also measured in four time periods. The second assay analyzed the influence of six auxin concentrations on the rooting phase. The first assay showed that the root systems grew more in treatment 3 (4.44 μM benzylaminopurine [BAP], 0.46 μM kinetin [KIN]) and reached greater dry mass in T8 (8.88 μM BAP,  0.92 μM KIN, 2.16 μM naphthalene acetic acid [NAA]). The largest fresh matter of the main shoot was found in T2 (4.44 μM BAP). The estimated DNA content varied depending on the presence of supplemental growth regulators, from 2.38 to 2.77 pg, and was greater in T4 (4.44 μM BAP, 1.08 μM NAA) and T5 (4.44 μM BAP, 0.46 μM KIN, 1.08 μM NAA). Results from the latter two treatments were not significantly different. Estimates of DNA content were precise, as indicated by coefficients of variation that were much lower than 5%. The results also showed quantitative variation of evaluated anatomical traits. In general, there was a thin epidermis layer with rectangular cells, followed by parenchyma with octahedral cells and differentiated xylem and phloem. In leaf parenchyma, the presence of idioblasts containing phenolic compounds was observed in all growth stages. In the rooting phase, the supplementary auxins affected the dry matter of the aerial part and roots. The highest averages were observed in treatments with 2.0 μM NAA.Keywords: Turmeric, micropropagation, flow cytometry, vegetal anatom

UTILIZAÇÃO DE NITRATO DE AMÔNIO E DE URÉIA COMO FONTES DE NITROGÊNIO NA MICROPROPAGAÇÃO DE AMOREIRA-PRETA

The high cost allied to the difficulty in the acquisition of the ammonium nitrate has been taking the accomplishment of works looking for an alternative for the substitution of this source of nitrogen. It was aimed at to study the technical viability of the substitution of the ammonium nitrate for urea, as source of nitrogen in the culture media for the blackberry in vitro cv. Tupy (Rubus sp). Nodal segments were used, already established in vitro, were inoculated in culture media MS and 50% MS, added of 1.0 mg. dm-3 of BAP, solidified with 6 g.dm-3 of agar, pH was adjusted for 5,8 and sterilized to 121 ºC and 0,1 mPa for 20 min. The treatments consisted of the substitution of 0; 20; 40; 60; 80 and 100% of NH4NO3 for urea, and the swinging of nitrogen supplied by the culture media MS it was not altered. The explants were maintained by 60 days in growth room with temperature of 27±1 ºC, photoperiod of 16 h and luminous intensity of 32 mmol m-2 s-1. The experiment was arranged in a completely randomized design, in factorial (6 x 2) using four repetitions with 16 plants each one. From the obtained results it can be concluded that the urea doesn't substitute NH4NO3 in the culture media MS as nitrogen source in the culture vitro of blackberry.   O elevado custo do nitrato de amônio, aliado à dificuldade de aquisição do mesmo, tem levado à realização de trabalhos, no sentido de buscar alternativas para a substituição dessa fonte de nitrogênio. Objetivou-se estudar a viabilidade técnica da substituição do nitrato de amônio por uréia, como fonte de nitrogênio no meio de cultura para o cultivo in vitro de amoreira-preta (Rubus sp) cultivar Tupy. Segmentos nodais de brotações pré-estabelecidas in vitro, foram inoculados em meio de cultura MS (Murashige & Skoog) e 50% MS, acrescido de 1,0 mg dm-3 de BAP, solidificado com 6 g dm-3 de ágar, pH ajustado para 5,8 e esterilizado a 121 °C e 0,1 mPa por 20 min. Os tratamentos consistiram da substituição de 0; 20; 40; 60; 80 e 100% do NH4NO3 por uréia, não sendo alterado o balanço de nitrogênio fornecido pelo meio MS. Os explantes foram mantidos por 60 dias em sala de crescimento com temperatura de 27±1 ºC, irradiância de 32 mmol m–2 s–1 e fotoperíodo de 16 h. O delineamento experimental utilizado foi inteiramente casualisado, em esquema fatorial (6 x 2), utilizando-se de quatro repetições constituídas de quatro tubos contendo um explante cada. Com base nos resultados obtidos, pode-se concluir que é possível a substituição parcial do nitrato de amônio no meio MS na micropropagação da amoreira-preta cv. Tupy.  

Eucalyptus shading and allelopathy in the germination and development of pitaya (Hylocereusundatus)

Eucalyptus spp. it is known to be part of most forests planted for commercial use in Brazil, however when intercropped with Pitaia (Hylocereus undatus), few studies report this interaction. The objective of this work was to evaluate the effects of shading and the existence of allelopathic interaction between Eucalyptus spp and pitaia (H. undatus) in the field, as well as the action of eucalyptus leaf extract in the germination of pitaia seeds in laboratory conditions. In the field experiment, the statistical model of randomized block design (DBC) was used, with the use of adult plants of pitaia and eucalyptus, evaluating the following variables: number of shoots in the aerial part; number of flowers; crown diameter; circumference of the cladode; number of fruits and the variation in the amount of light reaching the plants. It was observed that the plants that were outside the eucalyptus forest showed better results. In the second experiment, the allelopathic action of different concentrations of aqueous extracts of eucalyptus leaves on the germination of pitaia seeds was evaluated. This experiment was carried out in DIC with four repetitions of 60 pitaia seeds. These seeds were then subjected to treatments with different dilutions, varying from 0% (control), 12.5%, 25% and 50% of the stock solution. It was observed that as the leaf extract concentrations increased, germination decreased. The concentrations of 0% (control) and 12.5% ​​showed better results. In conclusion, in fact, eucalyptus exerted an allelopathic action on pitaia plants.Eucalyptus spp. it is known to be part of most forests planted for commercial use in Brazil, however when intercropped with Pitaia (Hylocereus undatus), few studies report this interaction. The objective of this work was to evaluate the effects of shading and the existence of allelopathic interaction between Eucalyptus spp and pitaia (H. undatus) in the field, as well as the action of eucalyptus leaf extract in the germination of pitaia seeds in laboratory conditions. In the field experiment, the statistical model of randomized block design (DBC) was used, with the use of adult plants of pitaia and eucalyptus, evaluating the following variables: number of shoots in the aerial part; number of flowers; crown diameter; circumference of the cladode; number of fruits and the variation in the amount of light reaching the plants. It was observed that the plants that were outside the eucalyptus forest showed better results. In the second experiment, the allelopathic action of different concentrations of aqueous extracts of eucalyptus leaves on the germination of pitaia seeds was evaluated. This experiment was carried out in DIC with four repetitions of 60 pitaia seeds. These seeds were then subjected to treatments with different dilutions, varying from 0% (control), 12.5%, 25% and 50% of the stock solution. It was observed that as the leaf extract concentrations increased, germination decreased. The concentrations of 0% (control) and 12.5% ​​showed better results. In conclusion, in fact, eucalyptus exerted an allelopathic action on pitaia plants

Índice de DNA e aspectos anatômicos da microenxertia de pitaia em diferentes porta-enxertos

The objective of this work was to evaluate the viability of the micrografting of yellow dragon fruit (Selenicereus megalanthus) on different rootstocks, based on DNA content and anatomical analyses. The used rootstocks were: yellow dragon fruit, white dragon fruit (Hylocereus undatus), Saborosa (Selenicereus setaceus) dragon fruit, and the Cebra and Orejona red dragon fruit (Hylocereus polyrhizus) varieties. The experimental design was completely randomized with five treatments and four replicates of five plants. After 30 days of cultivation, the following traits were evaluated: length and diameter of the micrografts and microrootstocks; and root length, percentage of setting, and fresh mass of the micrografts. Flow cytometry analyzes were performed before and after micrografting to verify genetic stability and the occurrence of endoreduplication. In addition, histological sections were made in the micrografting region to verify the connections of vessels and tissues between the graft and the rootstock. Endoreduplication was observed in all treatments. The amount of DNA in the yellow dragon fruit micrograft increased on the red Orejona variety. The presence of vessel connections was verified between the micrografts and microrootstocks. The yellow dragon fruit was also more vigorous when grafted on Orejona. Based on DNA content and anatomical analyses, in vitro yellow dragon fruit micrografting is feasible in all used rootstocks.O objetivo deste trabalho foi avaliar a viabilidade da microenxertia de pitaia amarela (Selenicereus megalanthus) sobre diferentes microporta-enxertos, com base em análises de conteúdo de DNA e anatômicas. Os porta-enxertos utilizados foram: pitaia amarela, pitaia branca (Hylocereus undatus), pitaia Saborosa (Selenicereus setaceus), e as variedades Cebra e Orejona de pitaia vermelha (Hylocereus polyrhizus). O delineamento experimental foi inteiramente casualizado, com cinco tratamentos e quatro repetições de cinco plantas. Após 30 dias de cultivo, avaliaram-se as seguintes características: comprimento e diâmetro dos microenxertos e dos microporta-enxertos; e comprimento de raízes, percentagem de pegamento e massa fresca dos microenxertos. Realizaram-se análises de citometria de fluxo antes e depois da microenxertia, para verificação da estabilidade genética e da ocorrência de endoreduplicação. Além disso, foram feitos cortes histológicos na região da microenxertia, para verificação das conexões dos vasos e dos tecidos entre o enxerto e o porta-enxerto. Observou-se endoreduplicação em todos os tratamentos. A quantidade de DNA do microenxerto de pitaia amarela aumentou sobre a variedade vermelha Orejona. Verificou-se a presença de conexões de vasos entre os microenxertos e os microporta-enxertos. A pitaia amarela também foi mais vigorosa quando enxertada sobre Orejona. Com base nas análises de conteúdo de DNA e anatômicas, a microenxertia de pitaia amarela in vitro é viável em todos os porta-enxertos utilizados

Modificações morfoanatômicas e fisiológicas de maracujazeiro fertilizado com silício

The objective of this work was to evaluate the effect of silicon fertilization on gas exchange, leaf anatomy, and ultrastructural characteristics of passion fruit (Passiflora edulis). The treatments comprised four concentrations of silicon (0, 0.28, 0.55, and 0.83 g per pot) at 1% silicic acid solution (SiO2.XH2O). This solution was applied around the stems of the plants. The first application was made 15 days after seedlings were transplanted. In total, three applications were made at 15-day intervals. The pots that constituted the control treatment received water in the same amount. After the final application, the plants were subjected to analyses of gas exchange, anatomical changes, and ultrastructural characteristics. The use of silicon promotes anatomical changes in passion fruit seedlings, such as increased adaxial epidermis thickness, reduced palisade parenchyma, and increased polar diameter/equatorial diameter ratio, which is related to stomata functionality. The concentrations of 0.55 and 0.83 g silicon per pot provide higher rates of photosynthesis, of transpiration, and stomatal conductance. The concentration of 0.83 g silicon per pot results in the greatest deposition of silicon in the abaxial epidermis of leaf surface.O objetivo deste trabalho foi avaliar o efeito da adubação silicatada nas trocas gasosas, na anatomia foliar e nas características ultraestruturais de maracujazeiro (Passiflora edulis). Os tratamentos consistiram em quatro concentrações (0, 0,28, 0,55, e 0,83 g por vaso) de silício, na forma de solução de ácido silícico (SiO2.XH2O) a 1%. Esta solução foi aplicada ao redor do caule das plantas. A primeira aplicação foi realizada 15 dias após o transplantio das mudas. No total, foram realizadas três aplicações, em intervalos de 15 dias. Os vasos que constituíram o controle (testemunha) receberam água na mesma quantidade. Após a última aplicação, as plantas foram submetidas a análises de trocas gasosas, alterações anatômicas e características ultraestruturais. O uso de silício promove mudanças anatômicas em mudas de maracujazeiro, como o aumento da espessura da epiderme adaxial, a redução do parênquima paliçádico e a maior relação diâmetro polar/diâmetro equatorial, que está relacionada à funcionalidade dos estômatos. As concentrações de 0,55 e 0,83 g de silício por vaso proporcionam maiores taxas fotossintéticas, de transpiração e de condutância estomática das mudas de maracujazeiro. A concentração de 0,83 g de silício por vaso proporciona maior deposição de silício na epiderme abaxial da superfície foliar

Regeneração de pitaya por organogênese indireta avaliada por microscopia eletrônica de varredura e citometria de fluxo

The objective of this work was to evaluate the induction of indirect organogenesis by concentrations of dichlorophenoxyacetic acid (2,4-D) and thidiazuron (TDZ) in pitaya (Hylocereus undatus) explants, using scanning electron microscopy and the flow cytometry technique. The treatments consisted of the concentrations of 0, 2.0, and 4.0 mg L-1 2,4-D and TDZ and of the combinations of these regulators. Percentages of callus coverage at 45 and 60 days were evaluated. The explants subjected to the treatments were analized by flow cytometry and scanning electron microscopy. All treatments induced endoreduplication, and there was no somaclonal variation. Under the combination of 2.0 mg L-1 TDZ and 4.0 mg L-1 2,4-D, calluses were formed in 95% of the explants, but were smaller than those produced with 2,4-D separately. The concentration of 2.0 mg L-1 TDZ induces the indirect organogenesis in pitaya explants, confirmed by the presence of conducting vessels through scanning electron microscopy.O objetivo deste trabalho foi avaliar a indução de organogênese indireta por concentrações de ácido diclorofenoxiacético (2,4-D) e tidiazurom (TDZ) em explantes de pitaia (Hylocereus undatus), por meio de microscopia eletrônica de varredura e da técnica de citometria de fluxo. Os tratamentos consistiram das concentrações de 0, 2,0 e 4,0 mg L-1 de 2,4-D e TDZ e das combinações desses reguladores. Avaliaram-se as percentagens de cobertura de calos aos 45 e 60 dias. Os explantes submetidos aos tratamentos foram analizados por citometria de fluxo e microscopia eletrônica de varredura. Todos os tratamentos induziram endorreduplicação, e não houve variação somaclonal. Na combinação de 2,0 mg L-1 TDZ e 4,0 mg L-1 2,4-D, calos foram formados em 95% dos explantes, mas foram menores do que os produzidos com 2,4-D separadamente. A concentração de 2,0 mg L-1 de TDZ induz organogênese indireta em explantes de pitaia, comprovada pela presença de vasos condutores por meio da microscopia eletrônica de varredura