Artificial pollination and use of growth regulators in atemoya 'Gefner' fruits

The objective was to study the effectiveness of the growth regulator (ANA + GA3) associated or not to the application of adjuvant and artificial pollination in 'Gefner' atemoya. The experiment was conducted in the experimental orchard at Florida's Tropical Research and Education Center. The experimental design was in a randomized block, with 14 treatments, 10 repetitions and 3 flowers per plot. The highest percentages of fixed fruits were obtained with hand pollination ­ HP and 450 NAA + 1250 GA3 mg L-1 + adjuvant and HP. The use of hand pollination for 'Gefner' atemoya tree proved to be the most efficient method so far. Applying growth regulator without artificial pollination produces parthenocarpic fruits, however with high rate of abortions, and small fruits. Growth regulators together with hand pollination produces small and uneven fruits, and cause reduction in the fruits' titratable acidity. The use of adjuvant caused low fixation and toxicity to fruits, and its use is not recommended.

In vitro establishment and multiplication of Echynochloa polystachya

The objective of this work was to carry out the in vitro establishment of Echynochloa polystachya aiming at obtaining a micropropagation protocol for works involving the selection of superior genotypes and the cultivation of the species. E. polystachya stems were collected in the municipality of Manaus-AM. Explants were inoculated in test tubes containing Murashige and Skoog (MS) medium. Thirty days after in vitro establishment, the rate of sprouting and contamination were evaluated. Experiments were also carried out to assess the effects of sucrose and 6-benzylaminopurine (BAP) concentrations on the tillering rate of explants. It was found that during the successive subcultures there was a decrease in internodes and the consequent loss of vigor. There were responses in the multiplication rate at concentrations starting from 45 g L-1 sucrose. In addition, BAP and sucrose interfered the development and in vitro multiplication. Sucrose in conjunction with BAP was harmful and shortened internodes. The physiological state of the explants for the species under study was intrinsically linked to the concentrations of sucrose used for the culture medium and the concentrations of BAP. However, the sucrose and BAP concentrations suggested for in vitro cultivation of E. Polystachya must be adjusted during successive subcultures. Absence of contamination in the in vitro establishment occurred at concentrations 15, 30 and 60 g L-1 sucrose. The combination of 1.5 mg L-1 BAP and 30 g L-1 sucrose promoted greater induction of sprouts. In addition, the in vitro rooting of E. polystachya was 45%.

Application methods of biostimulants affect the production and postharvest conservation of yellow melon

Worldwide, Brazil holds the fifth position in melon fruits exportation, further expanding its products to provide for the growing demand. This expansion is the result of the development and application of new technologies, including the management of the use of biostimulants. However, for melon crops, the information in the literature on the use of biostimulants remains limited to the effects of different doses on fruit quality at the time of harvest. Therefore, this study aimed to evaluate the influence of different methods of pre-harvest application of two biostimulants on the production and postharvest conservation of fruits of yellow melon cv. Iracema. The treatments consisted of a combination of three factors: two plant biostimulants (Crop Set® and Spray Dunger®), two application methods of the products (fertigation and spraying), and five times of postharvest storage (0, 14, 21, 28 and 35 days). An additional control treatment corresponded to plants without biostimulant application. The fruits were evaluated for production and physicochemical attributes: average mass, yield, flesh firmness, titratable acidity, soluble solids content, SSC/TA ratio, pH, total soluble sugars, and weight loss. Fertigation is the recommended application method of biostimulants for yellow melon due to its effect on the increase of average mass, yield, flesh firmness, soluble solids content, and total soluble sugars of the fruits in relation to the spraying method.

Callus induction, Indirect Organogenesis and Plantlet Regeneration from different explants of Vernonia anthelmintica (L.) Willd

Present study was conducted to standardize callus development and indirect organogenesis from differentexplants of Vernonia anthelmintica (L.) Willd. Among, the various hormonal combinations tested: IndoleAcetic Acid (IAA) and BA and IAA and Kinetin combinations were found to be optimum for inducing callusingwithin a time span of 10 days. Best callus response was observed in 1.5 mg l−1 IAA and 1.5 mg l−1 BA,which produced white friable callus. Best indirect shoot organogenesis was observed in 4 mg l−1 BA and6 mg l−1 kinetin. Elongated shoots when transferred on to half strength Murashige and Skoog (MS) Mediumsupplemented with Indole-3-butyric acid (IBA), rooting was observed. MS medium fortified with 2 mg l−1 IBAshowed better rooting than all other concentrations tested. This concentration produced maximum number ofroots and maximum percentage of rooting. Plantlets developed by indirect organogenesis of V. anthelminticawere successfully acclimatized to field conditions

Micropropagation of Stevia rebaudiana plants / Micropropagação de plantas de Stevia rebaudiana

ABSTRACT: The aim of the study was to develop optimum composition of plant growth regulators in media for the propagation and rooting of shoots of stevia (Stevia rebaudiana Bertoni) in in vitro cultures. Single-node shoot fragments obtained from plants propagated on MS medium were placed onto media supplemented with: BAP, 2iP and KIN at concentrations: 0.5, 1, 2 and 5 mg∙dm-3, whereas at the rooting stage with addition of: IAA, IBA and NAA at concentrations 1, 2, 4 and 8 mg∙dm-3. The highest number of shoots and leaves was reported for plants propagated on MS medium enriched with 0.5 mg∙dm-3 BAP. The greatest number of the longest roots was developed by stevia on the MS medium enriched with 1 mg∙dm-3 IAA.

RESUMO: O objetivo do estudo foi desenvolver uma composição ótima de reguladores de crescimento em meios para a propagação e enraizamento de brotos de estévia (Stevia rebaudiana Bertoni) em culturas in vitro. Fragmentos de parte aérea obtidos de plantas propagadas em meio MS foram colocados em meio suplementado com: BAP, 2iP e KIN nas concentrações: 0.5, 1, 2 e 5 mg∙dm-3, enquanto no estádio de enraizamento com adição de: IAA, IBA e ANA nas concentrações 1, 2, 4 e 8 mg∙dm-3.O maior número de brotações e folhas foi encontrado para plantas propagadas em meio MS enriquecido com 0.5 mg∙dm-3 de BAP. O maior número de raízes mais longas foi desenvolvido por estévia no meio MS enriquecido com 1 mg∙dm-3 de IAA.

A comparison of callus induction in 4 Garcinia species

Background: This research is intended to determine suitable types and concentrations of plant growth regulators (PGRs) to induce callus on stem and leaf sections of 4 species of the genus Garcinia, namely, Garcinia mangostana, Garcinia schomburgkiana, Garcinia cowa, and Garcinia celebica. The base medium was MS medium containing 30 g l -1 sucrose, 0.5 g l-1 polyvinylpyrrolidone (PVP), and 7 g l-1 agar, and for the different treatments, PGRs were added to the medium as follows: thidiazuron (TDZ) at concentrations of 0, 0.1, 0.5, 1, and 2 mg l-1; 6-(3- hydroxybenzylamino) purine (meta-topolin) at concentrations of 0, 0.5, 2.5, and 5 mg l-1; 4-amino-3,5,6- trichloro-2-pyridinecarboxylic acid (picloram) at concentrations of 0, 0.5, 2.5, and 5 mg l-1; and 2,4- dichlorophenoxyacetic acid (2,4-D) at concentrations of 0, 0.5, 1, 2, and 4 mg l-1. The occurrence of callus was observed after 4 weeks. Results: A maximum of 100% and 93% of G. mangostana leaf explants formed callus in the 0.5 mg l-1 and 1 mg l-1 TDZ treatments, respectively, while 100% of G. schomburgkiana stem explants formed callus in the 1 mg l-1 TDZ treatment and 89% of G. schomburgkiana leaf explants formed callus in the 0.5 mg l-1 picloram treatment. The highest callus induction rate for G. cowa was 62% in the 1 mg l-1 TDZ treatment and for G. celebica was 56% in the 0.5 mg l-1•mT-1 treatment. Conclusions: For all 4 species, the greatest amount of large nodular callus was observed in the TDZ treatments. White, friable callus was observed on most of the 2,4-D and picloram treatment groups. Most meta-topolin treatments resulted in minimal callus formation.

Morphological and biochemical changes during somatic embryogenesis in mahogany, Swietenia macrophylla (Meliaceae)

Intensive exploitation of mahogany wood (Swietenia macrophylla, Meliaceae) has resulted in the loss of natural populations. Somatic embryogenesis offers an alternative to clonal propagation and conservation of mahogany. This study describes biochemical (carbohydrates, total phenols, total flavonoids, protein, and plant growth regulators content) and histological characteristics of the somatic embryogenesis process in mahogany. Calli were obtained by culturing cotyledons of seeds from immature fruits for six weeks on semi-solid MS medium supplemented with 1.0 mgL-1 of kinetin and 4.0 mgL-1 of 2, 4-D. Primary callus was cultured on half strength semi-solid MS medium supplemented with 1.0 mgl-1 6-BA (6-benzylaminopurine) and embryogenic structures were obtained. Embryo development from globular-shaped somatic embryos to the cotyledonary stage was confirmed by histology and scanning electron microscopy. Shoot initiation was observed after somatic embryos were transferred to germination and maturation medium. Endogenous concentrations of carbohydrates, total phenols, total flavonoids, protein, and plant growth regulators were determined in embryogenic (EC) and non-embryogenic (NEC) calli of mahogany. Embryogenic cultures contained significantly higher concentrations of IAA (indoleacetic acid), ABA (abscisic acid), and GAs (Gibberellins 1+3+20), whereas non-embryogenic calli contained more total phenols, flavonoids and resistant starch. Fructose and glucose were not present at detectable levels in EC or NEC, whereas soluble starch and sucrose were only detectable in EC. Concentrations of total proteins, Z/ZR (Zeatin/zeatin riboside) and iP/iPA (N6-(Δ2-isopentenyl) adenine and N6-(Δ2-isopentenyl) adenosine) were similar in EC and NEC.

La explotación intensiva de la madera de caoba (Swietenia macrophylla) ha provocado la pérdida de poblaciones naturales. La embriogénesis somática ofrece una alternativa a la propagación clonal y la conservación de esta especie. Este estudio describe las características bioquímicas (contenido de carbohidratos, fenoles totales, flavonoides totales, proteínas y reguladores del crecimiento) e histológicas del proceso de embriogénesis somática en caoba. Los callos se obtuvieron cultivando cotiledones de semillas de frutos inmaduros durante seis semanas en medio MS semisólido suplementado con 1.0 mgL-1 de kinetina y 4.0 mgL-1 de 2, 4-D. Luego se cultivó el callo primario en medio MS semisólido y un suplemento de 1.0 mgl-1 BA y se obtuvieron estructuras embriogénicas. El desarrollo de embriones somáticos de forma globular a la etapa cotiledonar se confirmó por histología y microscopía electrónica de barrido. La iniciación del brote se observó después de que los embriones somáticos se transfirieron a un medio de germinación y maduración. Se determinaron las concentraciones endógenas de carbohidratos, fenoles totales, flavonoides totales, proteínas y reguladores del crecimiento en callos embriogénicos (EC) y no embriogénicos (NEC) de caoba. Los cultivos embriogénicos contenían concentraciones significativamente más altas de IAA, ABA y GA, mientras que los callos no embriogénicos contenían más fenoles totales, flavonoides y almidón resistente. La fructosa y la glucosa no estaban presentes en niveles detectables en EC o NEC, mientras que el almidón soluble y la sacarosa solo se detectaron en el EC. Las concentraciones de proteínas totales, Z / ZR e iP / iPA fueron similares en EC y NEC.

De novo in vitro shoot morphogenesis from shoot tip-induced callus cultures of Gymnema sylvestre (Retz.) R. Br. ex Sm

BACKGROUND: Gymnema sylvestre is a medicinal woody perennial vine known for its sweetening properties and antidiabetic therapeutic uses in the modern and traditional medicines. Its over-exploitation for the therapeutic uses and to meet the demand of pharmaceutical industry in raw materials supply for the production of anti-diabetic drugs has led to considerable decline in its natural population. RESULTS: An efficient system of shoot bud sprouting from nodal segment explants and indirect plant regeneration from apical meristem-induced callus cultures of G. sylvestre have been developed on Murashige and Skoog (MS) medium amended with concentrations of cytokinins. Of the three growth regulators tested, N6-benzylaminopurine (BAP) was the most efficient and 2.0 mg L-1 gave the best shoot formation efficiency. This was followed by thidiazuron (TDZ) and kinetin (Kin) but, most of the TDZ-induced micro shoots showed stunted growth. Multiple shoot formation was observed on medium amended with BAP or TDZ at higher concentrations. The produced micro shoots were rooted on half strength MS medium amended with auxins and rooted plantlets acclimatized with 87% survival of the regenerates. CONCLUSIONS: The developed regeneration system can be exploited for genetic transformation studies, particularly when aimed at producing its high yielding cell lines for the anti-diabetic phytochemicals. It also offers opportunities for exploring the expression of totipotency in the anti-diabetic perennial vine.

Influence of Silver Nitrate on Somatic Embryogenesis Induction in Arabica Coffee (Coffea arabica L)

Abstract The influence of silver nitrate (AgNO3), benzyladenine (BAP), and indole-3-acetic acid (IAA) on low frequency somatic embryogenesis (LFSE) induction in Caturra and Catuaí arabica coffee was evaluated. For the Caturra cultivar, the production of somatic embryos was significantly increased by adding AgNO3 to the semisolid culture medium. The highest average number of somatic embryos for this cultivar was obtained using 6.6 μM BAP, 2.85 μM IAA, and 40 μM AgNO3. In contrast, for the Catuaí cultivar, the highest average number of somatic embryos was obtained using semisolid medium supplemented with 8.8 μM BAP, and 2.85 μM IAA. Using these protocols, somatic embryos were directly induced using leaf sections of in vitro plants of both coffee cultivars within 8 weeks. The somatic embryos developed into rooted plants with a 100% survival rate upon transfer to the greenhouse.

Effect of salicylic acid and silver nitrate on rutin production by Hyptis marrubioides cultured in vitro / Efeito do ácido salicílico e nitrato de prata na produção de rutina por Hyptis marrubioides cultivada in vitro

ABSTRACT: Hyptis marrubioides (Lamiaceae) is a medicinal plant that is native from Brazilian Cerrado. In vitro propagation techniques make use of elicitors to alter metabolic pathways, affecting how molecules are produced both qualitatively and quantitatively. This research aimed to evaluate how abiotic elicitors salicylic acid (SA) and silver nitrate (SN) at concentrations of 30µM or 60µM influence Hyptis marrubioides seedling growth by two different in vitro culture methods. The rutin content was quantified by HPLC-DAD. Compared to an untreated culture, the H. marrubioides methanolic extracts cultured in MS medium for 10 days followed by culture in MS medium containing SN (30µM) for 20 days had 1.28 times higher rutin content. In a second experiment, seedlings were cultured in MS medium for 20 days, and then the desired elicitor was added to the culture and allowed to remain in contact with the medium for three and six days. SA (30µM) gave the best results: rutin production was 16.56-foldhigher than the control after six days. SN (30µM) increased the rutin content by 1.17-fold. At the two concentrations evaluated during the elicitation experiments, neither SA nor SN altered the growth parameters shoot length, leaf number, and fresh and dry weight of H. marrubioides seedlings grown in vitro as compared to the control. Based on these results, the abiotic elicitors SA and SN successfully provide Hyptis marrubioides with increased rutin content in vitro.

RESUMO: Hyptis marrubioides (Lamiaceae) é uma planta medicinal nativa do Cerrado brasileiro. Técnicas de propagação in vitro fazem uso de elicitores para alterar as vias metabólicas, afetando a produção de moléculas qualitativa e quantitativamente. Este trabalho teve como objetivo avaliar como os elicitores abióticos ácido salicílico (SA) e nitrato de prata (SN) nas concentrações de 30µM ou 60µM influenciam no crescimento de plântulas de Hyptis marrubioides por dois diferentes métodos de cultivo in vitro. O teor de rutina foi quantificado por CLAE-DAD. Em comparação com uma cultura não tratada, os extratos metanólicos de H. marrubioides cultivados em meio MS por 10 dias, seguidos de cultura em meio MS contendo SN (30µM) por 20 dias, apresentaram 1,28 vezes maior teor de rutina. Em um segundo experimento, as plântulas foram cultivadas em meio MS por 20 dias, e então o elicitor desejado foi adicionado à cultura e deixado em contato com o meio por três e seis dias. SA (30µM) forneceu os melhores resultados na produção de rutina, sendo 16,56 vezes maior do que o controle após seis dias. SN (30µM) aumentou o teor de rutina em 1,17 vezes. Nas duas concentrações avaliadas durante os experimentos de elicitação, nem SA nem SN alteraram os parâmetros de crescimento, como comprimento da parte aérea, número de folhas ou peso fresco e seco das plântulas de H. marrubioides cultivadas in vitro em relação ao controle. Com base nestes resultados, os elicitores abióticos SA e SN forneceram com sucesso Hyptis marrubioides in vitro com maior conteúdo de rutina.

Induction and growth curve of calli from leaf and nodal explants of genipap / Indução e curva de crescimento de calos obtidos de explantes foliares e nodais de jenipapeiro

The aim of this study was to determine the effect of the auxin 2,4-D (2,4-dichlorophenoxyacetic) in calli formation from leaf and nodal segments of genipap and to characterize its growth curve. Explants obtained from shoots previously established from in vitro seedlings were used for calli induction. The experimental design was completely randomized in a 3x5x2 factorial with three accessions (NB, SA, SAL), five concentrations of 2,4-D (0.0; 2.0; 4.0, 6.0 or 8.0 mg L-1) and two times of measurement for calli fresh weight (30 and 60 days). There was callus formation in all treatments tested. It was observed that the best response for callus induction from leaf segments was with 2.0 mg L-1 of 2,4-D. For the nodal segment, the response among the accessions was different due to 2,4-D concentrations. The growth curve was plotted according to the fresh weight of callus obtained at intervals of 10 days up to 60 days. Through the established growth curve, the nodal-derived calli from accession SA should be transferred to a new medium, after 40 days of culture.

O objetivo desse trabalho foi determinar o efeito da auxina 2,4-D (ácido diclorofenoxiacético) na calogênese de segmentos foliar e nodal de jenipapeiro e caracterizar sua curva de crescimento. Explantes obtidos de brotações pré-estabelecidas a partir de plântulas in vitro foram utilizados na indução de calos. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 3x5x2, com três acessos (NB, SA e SAL), cinco concentrações de 2,4-D (0,0; 2,0; 4,0; 6,0 ou 8,0 mg L-1) e dois tempos de avaliação (30 e 60 dias) da massa fresca de calos. Houve formação de calos em todos os tratamentos testados. Observou-se que a melhor resposta de indução ocorreu na concentração de 2,0 mg L-1 para calos oriundos de segmentos foliares. Para o segmento nodal a resposta entre os acessos foi diferenciada em função das concentrações de 2,4-D. A curva de crescimento foi plotada a partir da massa fresca dos calos obtida em intervalos de 10 dias até os 60 dias. Através da curva de crescimento estabelecida, os calos derivados de segmentos nodais do acesso SA devem ser transferidos para um novo meio de cultura, 40 dias após à inoculação.

Influence of growth regulators on distribution of trichomes and the production of volatiles in micropropagated plants of Plectranthus ornatus

ABSTRACT The profile of volatile organic compounds, the glandular and non-glandular trichomes of Plectranthus ornatus, obtained by in vitro cultivation, was evaluated in plants grown in Murashide and Skoog medium supplemented with benylaminopurine at 4.5, 9.0, and 18.0 µM + naphthaleneacetic acid at 5.37 µM, kinetin at 4.7, 9.3 and 18.5 µM + naphthaleneacetic acid (5.37 µM) or Murashide and Skoog 0 medium (as a control). Scanning Electron Microscopy was performed on samples of the third leaf node of the 90 days old plants obtained from treatment with 4.5 or 9.0 µM benylaminopurine, and 4.7 or 9.3 µM kinetin. Headspace Solid Phase Micro-Extraction of the 30, 60 and 90 days old in vitro plants permitted to determinate by GC/MS the composition comprised of 62 compounds. The data were analyzed using Principal Component Analysis and Hierarchical Clustering Analysis and, the major constituents of these oils after treatment and aging were monoterpenes and sesquiterpenes. Morphoanatomical analysis of trichomes, by Scanning Electron Microscopy, enabled the identification of non-glandular trichomes and four types of glandular trichomes, which comprised capitate and peltate glandular trichomes that were distributed on both sides of the leaf. We observed that the regulators influenced qualitative and quantitative profiles of the volatile organic compounds and the number and distribution of hairs on the leaf surface.

Thidiazuron (TDZ) increases fruit set and yield of 'Hosui' and 'Packham's Triumph' pear trees

ABSTRACT The low fruit set is one of the main factors leading to poor yield of pear orchards in Brazil. The exogenous application of thidiazuron (TDZ) and aminoethoxyvinilglycine (AVG) has shown promising results in some pear cultivars and other temperate fruit trees. The objective of this study was to evaluate the effect of TDZ and AVG on fruit set, yield, and fruit quality of 'Hosui' and 'Packham's Triumph' pears. The study was performed in a commercial orchard located in São Joaquim, SC. Plant material consisted of 'Hosui' and 'Packham's Triumph' pear trees grafted on Pyrus calleryana. Treatments consisted on different rates of TDZ (0 mg L-1, 20 mg L-1, 40 mg L-1 and 60 mg L-1) sprayed at full bloom for both cultivars. An additional treatment of AVG 60 mg L-1 was sprayed one week after full bloom in 'Hosui'. The fruit set, number of fruit per tree, yield, fruit weight, seed number, and fruit quality attributes were assessed. Fruit set and yield of both cultivars are consistently increased by TDZ, within the rates of 20 to 60 mg L-1. Besides, its application increased fruit size of 'Hosui' and did not negatively affect fruit quality attributes of both cultivars.

Kernel size and weight affected by three plant bioregulators applied at bloom to Non Pareil and Carmel almond cultivars

Background: The yield of almonds [Prunus dulcis (Mill.) D.A. Webb] could be low due to climatic problems and any factor improving kernel size and weight, such as the use of plant bioregulators (PBRs), should be beneficial. Results: Three plant bioregulators: 24-epibrassinolide (BL), gibberellic acid (GA3) and kinetin (KN) were applied at three spray concentrations to Non Pareil and Carmel cultivars, at two phenological stages during bloom, in the 2014 and 2015 seasons. The results showed significant differences (P b 0.0001). For total dry weight of Non Pareil, the best treatment was BL (30 mg·L-1), with an average of 1.45 g, while the control was 1.30 g, at pink button during 2015. For Carmel, the best dry weight was 1.23 g, achieved with BL (30 mg·L-1) at fallen petals in both seasons. The average dry weight of the controls varied between 1.13 and 1.18 g. The greatest almond lengths and widths in Non Pareil were 24.98 mm and 15.05 mm, achieved with BL (30 mg·L-1) and KN (50 µL·L-1) treatments, respectively, applied at pink button in 2015. In Carmel, the greatest length and width were 24.38 and 13.44 mm, obtained with BL (30 mg·L-1) applied at the stages of pink button and fallen petals, respectively, in 2015. The control reached lengths between 22.33 and 23.38 mm, and widths between 11.99 and 12.93 mm. Conclusions: The use of the bioregulators showed significant favorable effects on dry weight, length and width of kernels at harvest, in both cultivars.

Micropropagation of the new apple rootstock ‘G. 814’ / Micropropagação do novo porta-enxerto de macieira ‘G. 814’

ABSTRACT: International breeding programs launched new genetic material of apple rootstocks that in addition to precocity and great yield are resistant to major diseases and soil pests encountered in the largest apple producing regions in Brazil. Given this, there is a necessity for vegetative propagation of these materials for study and possible replacement of existing rootstocks. The objective was to adapt a micropropagation protocol for new apple rootstock ‘G. 814’. In the multiplication phase were evaluated BAP concentrations: 0; 0.5; 1; 2 and 4mg L-1 and in the rooting phase were evaluated IBA concentrations: 0; 0.25; 0.50; 1; 1.5 and 2.5mg L-1. These new results demonstrated that this new rootstock selection can be propagated with this tissue culture adapted protocol. For the successful in vitro propagation of apple rootstock ‘G. 814’ it is indicated the use of 1mg L-1 BAP at multiplication phase and 1.5mg L-1 IBA at rooting phase.

RESUMO: Programas de melhoramento internacional lançaram novos materiais genéticos de porta-enxertos de macieira que além de precoces e produtivos são resistentes as principais doenças e pragas de solo das maiores regiões produtoras de maçã no Brasil. Diante disto, existe a necessidade de propagação vegetativa destes materiais para estudos e possível substituição dos atuais porta-enxertos. O objetivo foi adaptar um protocolo de micropropagação para o novo porta-enxerto de macieira ‘G. 814’. Na fase de multiplicação dos explantes foram avaliadas concentrações de BAP: 0; 0.5; 1; 2 e 4mg L-1 e na de enraizamento concentrações de AIB: 0; 0.25; 0.50; 1; 1.5 e 2.5mg L-1. Esta seleção de porta-enxerto pode ser micropropagada com este protocolo adaptado. Para o sucesso na propagação in vitro do porta-enxerto de macieira ‘G. 814’ é indicado o uso de 1mg L-1 de BAP na fase de multiplicação e de 1.5mg L-1 de AIB na fase de enraizamento.

In vitro morphogenic response from zygotic embryos of Genipa americana / Resposta morfogênica in vitro de embriões zigóticos de Genipa americana

ABSTRACT: The aim of this study was to evaluate the in vitro morphogenic potential of genipap (Genipa americana L.) zygotic embryos. Seeds obtained from ripe fruits had their zygotic embryos excised and inoculated in MS medium with 4.44µM of 6-benzylaminopurine (BAP) and supplemented with 0.0; 1.07; 2.14 and 3.21µM of naphthalene acetic acid (NAA). The potential of explants regeneration and the shoot length and number of leaves in plantlets were evaluated. The in vitro regeneration of genipap is possible from the conversion of zygotic embryos in a MS medium with 4.44µM BAP supplemented with 3.21µM NAA.

RESUMO: O objetivo do trabalho foi avaliar o potencial morfogênico in vitro de embriões zigóticos de jenipapeiro (Genipa americana L.). Sementes obtidas de frutos tiveram seus embriões zigóticos excisados e inoculados em meio MS com 4,44µM de 6-benzilaminopurina (BAP) suplementado com 0,0; 1,07; 2,14 e 3,21µM de ácido naftaleno acético (ANA). O potencial de regeneração dos explantes e o comprimento da parte aérea e o número de folhas nas plântulas formadas foi avaliado. Observou-se que é possível a regeneração in vitro de jenipapeiro a partir da conversão de embriões zigóticos em meio MS com 4,44µM de BAP, suplementado com 3,21µM de ANA.

Meristem culture and subsequent micropropagation of Chilean strawberry (Fragaria chiloensis (L) Duch. )

BACKGROUND: Vegetative propagation of Fragaria sp. is traditionally carried out using stolons. This system of propagation, in addition to being slow, can spread plant diseases, particularly serious being viral. In vitro culture of meristems and the establishment of micropropagation protocols are important tools for solving these problems. In recent years, considerable effort has been made to develop in vitro propagation of the commercial strawberry in order to produce virus-free plants of high quality. These previous results can serve as the basis for developing in vitro-based propagation technologies in the less studied species Fragaria chiloensis. RESULTS: In this context, we studied the cultivation of meristems and establishment of a micropropagation protocol for F. chiloensis. The addition of polyvinylpyrrolidone (PVP) improved the meristem regeneration efficiency of F. chiloensis accessions. Similarly, the use of 6-benzylaminopurine (BAP) in the culture media increased the average rate of multiplication to 3-6 shoots per plant. In addition, the use of 6-benzylaminopurine (BAP), had low levels (near zero) of explant losses due to oxidation. However, plant height as well as number of leaves and roots were higher in media without growth regulators, with average values of 0.5 cm, 9 leaves and 4 roots per plant. CONCLUSIONS: For the first time in Chilean strawberry, meristem culture demonstrated to be an efficient tool for eliminating virus from infected plants, giving the possibility to produce disease free propagation material. Also, the addition of PVP into the basal MS medium improved the efficiency of plant recovery from isolated meristems. Farmers can now access to high quality plant material produced by biotech tools which will improve their technological practices.

Investigating the effects of phytohormones on growth and β-carotene production in a naturally isolates stain of Dunaliella salina.

The algae of the genus Dunaliella especially D. salina is among the microalgae most studied for mass culture. This alga is the richest algal source of glycerol and β-carotene, which is grown as a food source in aquaculture. In this study the effect of growth regulators (kinetin, gibberellic acid, indole-3-acetic acid, 6γ, γ-dimethylallyl aminopurine, salicylic acid and benzyl aminopurine) on the growth and β-carotene production in D. salina (MCCS 001) was investigated. Results pointed out that the β-carotene content and cell growth of D. salina could achieve the highest rates when kinetin and indole-3-acetic acid were used at 1 µM. Besides, it was shown that almost all of plant hormones has a positive effect on cell growth and β-carotene production in the microalga D. salina.

Effects of variations in culture media and hormonal treatments upon callus induction potential in endosperm explant of Barringtonia racemosa L

Objective: To induce callus from the medicinally valuable species, Barringtonia racemosa L. (B. racemosa) whereby the formation of callus is essential for micropropagation studies and in vitro plant secondary metabolites production. Methods: The callus induction potential in B. racemosa was assessed from endosperm explant cultured on different culture media and plant hormonal treatments. Lloyd and McCown's woody plant medium and Murashige and Skoog's medium were used in the study as culture media. On the other hand, various concentrations and combinations of 2,4-dichlorophenoxyacetic acid (1.0-2.0 mg/L) and kinetin (0.5-2.5 mg/L) had been incorporated in the culture media to exert the effects of auxin and cytokinin on callus induction. Results: From the present study, it was found that the profuse [(1.681 ± 0.770) g fresh weight, (0.239 ± 0.239) g dry weight] and friable callus formation was optimally produced with desirable morphology and considerable percentage of callus induction (56.70%) in endosperm explants cultured on 1.0 mg/L 2,4-dichlorophenoxyacetic acid and 1.5 mg/L kinetin in Murashige and Skoog's medium. Conclusions: A reliable protocol for inducing callus formation of profuse and friable morphology in endosperm explant of B. racemosa had therefore been successfully established.

Efficient In Vitro Somatic Embryogenesis and Plant Regeneration from Mature and Immature Embryos of Wheat ( Triticum aestivum L.)

ABSTRACT An efficient regeneration system is a pre-requisite for the application of genetic transformation and functional genomics study of important plants. In this study, the effect of different factors (plant growth regulators, casein hydrolysate, aspartic acid and ascorbic acid) on in vitro embryogenesis and regeneration of Arta, Bahar and Zagros cultivars from mature and immature explants were investigated. Immature and mature embryos were dissected from disinfected seeds 20-25 days after pollination and imbedded mature seeds, respectively, and cultured on MS (Murashige and Skoog) medium supplemented with different compounds. The results showed that immature embryos expose high capacity of embryogenesis and regeneration in comparison with mature embryos. There were significant differences between cultivars in terms of the percentage of callus induction and regeneration. Plant growth regulators had significant effect on percentage of callus induction in mature explants and percentage of regeneration from both explants. In immature explants, the highest percentage of regeneration (65%) was achieved with the Arta cultivar calli derived from MS medium supplemented with 1mg/L 2,4-D, 2 mg/L Picloram and 200 mg/L casein hydrolysate, and subcultured on MS medium. Also, the highest percentage of regeneration (52.38%) from mature embryo explants was achieved in the Arta cultivar with callus induction on MS medium supplemented with 1 mg/L 2,4-D, 2 mg/L Picloram and 200 mg/L casein hydrolysate and regeneration on MS medium containing 0.05 mg/L NAA.