Bioprocess of Gibberellic Acid by Fusarium fujikuroi: The Challenge of Regulation, Raw Materials, and Product Yields.

Gibberellic acid (GA3) is a tetracyclic diterpenoid carboxylic acid synthesized by the secondary metabolism of Fusarium fujikuroi. This phytohormone is widely studied due to the advantages it offers as a plant growth regulator, such as growth stimulation, senescence delay, flowering induction, increased fruit size, and defense against abiotic or biotic stress, which improve the quality and yield of crops. Therefore, GA3 has been considered as an innovative strategy to improve agricultural production. However, the yields obtained at large scale are insufficient for the current market demand. This low productivity is attributed to the lack of adequate parameters to optimize the fermentation process, as well as the complexity of its regulation. Therefore, this article describes the latest advances for potentializing the GA3 production process, including an analysis of its origins from crops, the benefits of its application, the related biosynthetic metabolism, the maximum yields achieved from production processes, and their association with genetic engineering techniques for GA3 producers. This work provides a new perspective on the critical points of the production process, in order to overcome the limits surrounding this modern line of bioengineering.

Interaction between fructan metabolism and plant growth regulators.

MAIN CONCLUSION: The relationship of fructan to plant growth regulators is clearly more complicated than it looks and is likely related to differences between fructan molecules in size and structure as well as localization. Fructans are a complex group of carbohydrates composed mainly of fructose units linked to a sucrose molecule. Fructans are present in plants as heterogeneous mixtures with diverse molecular structures and mass, different polymerization degrees, and linkage types between fructosyl residues. Like sucrose, they are frequently stored in leaves and other organs, acting as carbohydrate reserves. Fructans are synthesized in the cell vacuole by fructosyltransferase enzymes and catabolized by fructan exohydrolase enzymes. Several publications have shown that fructan metabolism varies with the stage of plant development and in response to the environment. Recent studies have shown a correlation between plant growth regulators (PGR), fructan metabolism, and tolerance to drought and cold. PGR are compounds that profoundly influence the growth and differentiation of plant cells, tissues, and organs. They play a fundamental role in regulating plant responses to developmental and environmental signals. In this review, we summarize the most up-to-date knowledge on the metabolism of fructans and their crosstalk with PGR signaling pathways. We identify areas that require more research to complete our understanding of the role of fructans in plants.

Application of abscisic acid (S-ABA) at different stages of ripening on color development of 'Rubi' table grape / Aplicação do ácido abscísico (S-ABA) durante a maturação no desenvolvimento da cor da uva fina de mesa 'Rubi'

The color of the berries is an important aspect of the quality of table grapes and crucial for marketing. The 'Rubi' table grapes grown in the subtropical climate generally lack color intensity due to the inhibition of anthocyanins by high temperatures during ripening. The exogenous application of abscisic acid (S-ABA) can be used to overcome this problem as the accumulation of anthocyanins in the berry skin is regulated by this plant growth regulator. The objective of this study was to assess the effect of the exogenous application of S-ABA at different stages of ripening on color development in 'Rubi' table grapes using the soluble solids (SS) content as a marker of ripening. The study was conducted during two seasons in commercial vineyards. The first trial was conducted in Marialva, Parana, Brazil, during the 2019 summer season crop (harvest in December). S-ABA (400 mg L-1) was exogenously applied at different stages of ripening of 'Rubi' table grapes (determined by the SS content of the berries): control (without application); SS = 8-9 ºBrix; SS = 10-11 ºBrix; SS = 8-9 ºBrix (two applications; the second one applied 10 days after the first); and SS = 10-11 ºBrix (two applications; the second one applied 10 days after the first). The second trial was conducted in Cambira, Parana, Brazil, during the 2020 off-season crop (harvest in May). S-ABA (400 mg L-1) was exogenously applied at different stages of ripening of 'Rubi' grapes: control (without application); SS = 6-7 ºBrix; SS = 7-8 ºBrix; SS = 9-10 ºBrix; SS = 6-7 ºBrix (two applications; the second one applied 14 days after the first); SS = 7-8 ºBrix (two applications; the second one applied 14 days after the first); and SS = 9-10 ºBrix (two applications; the second one applied 14 days after the first).(AU)

A cor das bagas é um aspecto importante de qualidade e comercialização de uvas de mesa. A uva fina de mesa 'Rubi' produzida em clima subtropical geralmente apresenta deficiência de cor devido à inibição da formação de antocianinas pelas altas temperaturas durante a maturação. Um dos métodos utilizados para superar esse problema é a aplicação exógena de ácido abscísico (S-ABA), uma vez que o acúmulo de antocianinas na casca das bagas é controlado por esse regulador vegetal. O objetivo deste trabalho foi determinar o efeito da aplicação do S-ABA em diferentes fases de maturação no desenvolvimento da cor da uva fina de mesa 'Rubi', visando o incremento e uniformização da cor dos seus cachos, tendo como referência o teor de sólidos solúveis (SS) das bagas. O experimento foi avaliado em dois ensaios a campo, em pomares comerciais. O primeiro ensaio foi realizado em Marialva, Paraná, Brasil, durante a safra de verão (colheita em dezembro) de 2019. Os tratamentos foram constituídos da aplicação de S-ABA na concentração de 400 mg L-1, em diferentes fases de maturação da uva 'Rubi', de acordo com o teor de SS das bagas, assim descritos: controle (sem aplicação); SS = 8-9 ºBrix; SS = 10-11 ºBrix; SS = 8-9 ºBrix em duas aplicações, sendo a segunda realizada aos 10 dias após a primeira; e SS = 10-11 ºBrix, em duas aplicações, sendo a segunda realizada aos 10 dias após a primeira. O segundo ensaio foi realizado em Cambira, Paraná, Brasil, durante a safra temporona ou de outono (colheita em maio) de 2020. Os tratamentos foram constituídos da aplicação de S-ABA na concentração de 400 mg.L-1 em diferentes fases de maturação da uva 'Rubi', de acordo com o teor de SS das bagas, assim descritos: controle (sem aplicação); SS = 6-7 ºBrix; SS = 7-8 ºBrix; SS = 9-10 ºBrix; SS = 6-7 ºBrix em duas aplicações, sendo a segunda realizada aos 14 dias após a primeira; SS = 7-8 ºBrix em duas aplicações, sendo a segunda realizada aos 14 dias após a primeira; e SS = 9-10 ºBrix em duas aplicações, sendo a segunda realizada aos 14 dias após a primeira. O delineamento experimental de ambos experimentos foi em blocos casualizados com 4 repetições, sendo que cada parcela foi composta por uma videira. As variáveis analisadas foram antocianinas totais, índice de cor (CIRG), e atributos (L*, C*, h° e ΔE) das bagas.(AU)

Trinexapac-ethyl application time in the crop corn agronomic performance grown under different plant arrangements / Épocas de aplicação de Trinexapac-etil no desempenho agronômico do milho cultivado sob diferentes arranjos de plantas

Reduced row spacing promotes more uniform spatial distribution of plants in the field. However, the adoption of reduced row spacing only is possible with smaller plants, which may be obtained with the use of plant growth regulator. This study aimed to evaluate the agronomic performance of the first corn crop with Trinexapac-ethyl applied at the different plant development stages and grown under different row spacing, with the same plant population. The experiments were arranged in a split-plot randomized block design with four replications, with row spacing for the plots (0.45 and 0.90 m) and Trinexapac-ethyl (TE) application time to subplots (control without application, at the V3, V6, V9 and V12 phenological stages). The Trinexapacethyl application time interacted with row spacings changing the growth and yield performance of the corn crop. For 0.45 m spacing Trinexapac-ethyl application at V12 and for 0.90 m spacing application at V9 and V12 reduced plant height and ear height. Trinexapac-ethyl application at V9 for both row spacings changed the plant architecture without changing the ear length and grain yield.(AU)

A redução do espaçamento entre linhas promove distribuição espacial mais uniforme das plantas na lavoura. Entretanto, a adoção do espaçamento reduzido só é possível com cultivares de menor porte, o que pode ser obtido com o uso de regulador de crescimento. Objetivou-se avaliar o desempenho agronômico do milho de primeira safra, submetido à aplicação de Trinexapac-etil (TE) em diferentes estádios de desenvolvimento vegetativo e cultivado sob diferentes espaçamentos entre linhas, com mesma população de plantas. Utilizou-se o delineamento experimental de blocos casualizados com parcelas subdivididas, com quatro repetições. As parcelas receberam os dois espaçamentos entre linhas (0,45 e 0,90 m) e as subparcelas as cinco épocas de aplicação de TE (testemunha sem aplicação, V3, V6, V9 e V12). A época de aplicação de Trinexapac-etil interage com os espaçamentos entre linhas alterando o crescimento e o desempenho produtivo da cultura. Para o espaçamento 0,45 m a aplicação de Trinexapac-etil em V12 e para o 0,90 m a aplicação em V9 e V12 reduz a altura de planta e de inserção de espiga. A aplicação de Trinexapac-etil em V9 para ambos os espaçamentos modifica a arquitetura da planta sem alterar o comprimento da espiga e produtividade de grãos.(AU)

Indolebutyric acid on the rooting of Fuchsia spp. cuttings / Ácido indolbutírico no enraizamento de estacas de Fuchsia spp

The princess earring is an ornamental plant native to the southern region of Brazil, much appreciated due to the beauty of its outstanding and colorful flowers. This study evaluated the effect of different doses of synthetic auxin indolebutyric acid (IBA) on the rooting of herbaceous cuttings of Fuchsia regia (Vell.) Munz, native species, and Fuchsia hybrida Hort. Ex Siebert & Voss commercial variety 'General Monk Red Blue'. The experiment was carried out in a greenhouse following a randomized block design with a 2x5 factorial arrangement (two genotypes of Fuchsia x five IBA doses). The IBA doses consisted in the concentrations of 0, 200, 400, 600 and 800 mg.L-1. Evaluations were performed 20 days after staking. The parameters evaluated were length of the largest root, number of roots per cutting, fresh weight and dry weight of the aerial part and roots. The concentration of 800 mg.L-1 of indolebutyric acid resulted in greater rooting of the cuttings of both Fuchsia materials tested. Therefore, the use of IBA (800 mg.L-1) provided better quality rooted cuttings, with greater length and number of roots.

O brinco-de-princesa é uma planta ornamental nativa da região Sul do Brasil, muito apreciada devido a beleza de suas flores pendentes e coloridas. O presente trabalho foi realizado com o objetivo de avaliar o efeito de diferentes doses de auxina sintética ácido indolbutírico (IBA) no enraizamento de estacas herbáceas de Fuchsia regia (Vell.) Munz, espécie nativa, e Fuchsia hybrida Hort. Ex Siebert & Voss variedade comercial 'General Monk Red Blue'. O experimento foi conduzido em casa-de-vegetação e o delineamento experimental foi em blocos ao acaso com arranjo fatorial 2x5 (dois genótipos de Fuchsia x cinco tratamentos). Os tratamentos consistiram em controle, e doses de IBA (mg.L-1) (0, 200, 400, 600 e 800). As avaliações foram feitas 20 dias após o estaqueamento. Os parâmetros avaliados foram: comprimento da maior raiz, número de raízes formadas por estaca, massa fresca e massa seca da parte aérea e das raízes. A concentração de 800 mg.L-1 de ácido indolbutírico resultou em maior enraizamento das estacas de ambos os materiais de Fuchsia testados. Portanto, o uso de IBA (800 mg.L-1) proporcionou a obtenção de mudas enraizadas de melhor qualidade, maior comprimento e número de raízes.

Growth regulation of bermudagrass (Cynodon dactylon) and zoysiagrass (Zoysia japonica) with glyphosate.

Glyphosate can generate positive effects on turfgrass maintenance as a form of growth control by decreasing the expenses associated with mowing. However, there is little information about the effects of this herbicide on turfgrasses. This study aimed to evaluate the response of bermudagrass and zoysiagrass to the herbicide glyphosate as a growth regulator. Two studies were performed in a greenhouse and repeated at different times. The treatments involved application of glyphosate at 10 different rates (0, 5.625, 11.25, 22.5, 45, 90, 180, 360, 720, and 1.440 g ae ha-1) with four replicates. Evaluations of green cover by digital analysis, injury, and plant height were performed at 7, 14, 21, and 28 days after application, and shoot dry matter of clippings was determined for the last evaluation period. Bermudagrass and zoysiagrass presented variedtolerance to glyphosate toxicity. Overall, the digital analysis showed that green content was negatively influenced by the increase in visual injury caused by glyphosate application. Moreover, increasing the glyphosate rate decreased plant height and shoot dry matter in both turfgrasses. Glyphosate application rates up to 45 g ae ha-1 for bermudagrass and 90 g ae ha-1 for zoysiagrass decreased plant growth without affecting the factors analyzed in this study.

Cytokinin induces the development of gabirobeira root cuttings / Citocininas induzem o desenvolvimento de estacas de raiz de gabirobeira

The gabirobeira is a species native to the Brazilian Cerrado with potential for use in cropping systems. This study evaluated the effect of the cytokinin 6-benzylaminopurine (BAP) on root cuttings of gabirobeira (Campomanesia adamantium). The plant material was obtained from gabirobeira progenies of one and two-years-old. The cuttings were segmented in 5 cm length and 1.90 to 3.22 mm diameter, immersed in the following BAP concentrations: 0.0; 1.0; 2.0 and 4.0 mg L-1 for 15 seconds and planted in trays containing the substrate Bioplant®. A complete randomized experimental design was adopted in a factorial scheme 2x4, (cuttings age x BAP concentrations) with fifteen replicates per treatment. After 140 days the number of cuttings with shoots, number of shoots, number of leaves, and diameter of the main root were evaluated. The better development of the cuttings was observed on progenies of two-years-old. The lowest cytokinin concentrations promoted the better emission and number of shoots of the progenies from both ages.(AU)

A gabirobeira é uma espécie nativa do Cerrado brasileiro com potencial para uso em sistemas de cultivo. O objetivo deste estudo foi avaliar o efeito da 6-benzilaminopurina (BAP) em estacas radiculares de progênies de Gabirobeira (Campomanesia adamantium). As estacas radiculares foram obtidas de progênies de Gabirobeira de um e dois anos de idade. Estes foram segmentados em 5 cm de comprimento e apresentavam entre 1,90 a 3,22 mm de diâmetro, imersos nas concentrações: 0.0; 1.0; 2.0 e 4.0 mg L-1 de BAP por 15 segundos e plantados em bandejas contendo Bioplant®. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 2x4 (idades das estacas x concentrações de BAP), com quinze repetições por tratamento. Após 140 dias, foram avaliados o número de estacas com brotações, número de brotações, número de folhas e diâmetro da raiz principal. Estacas de raízes de progênies de dois anos de idade apresentaram melhor desenvolvimento. Menores concentrações de citocinina trouxeram melhores resultados de emissão e número de brotações das progênies de ambas as idades.(AU)

Cytokinin induces the development of gabirobeira root cuttings / Citocininas induzem o desenvolvimento de estacas de raiz de gabirobeira

ABSTRACT: The gabirobeira is a species native to the Brazilian Cerrado with potential for use in cropping systems. This study evaluated the effect of the cytokinin 6-benzylaminopurine (BAP) on root cuttings of gabirobeira (Campomanesia adamantium). The plant material was obtained from gabirobeira progenies of one and two-years-old. The cuttings were segmented in 5 cm length and 1.90 to 3.22 mm diameter, immersed in the following BAP concentrations: 0.0; 1.0; 2.0 and 4.0 mg L-1 for 15 seconds and planted in trays containing the substrate Bioplant®. A complete randomized experimental design was adopted in a factorial scheme 2x4, (cuttings age x BAP concentrations) with fifteen replicates per treatment. After 140 days the number of cuttings with shoots, number of shoots, number of leaves, and diameter of the main root were evaluated. The better development of the cuttings was observed on progenies of two-years-old. The lowest cytokinin concentrations promoted the better emission and number of shoots of the progenies from both ages.

RESUMO: A gabirobeira é uma espécie nativa do Cerrado brasileiro com potencial para uso em sistemas de cultivo. O objetivo deste estudo foi avaliar o efeito da 6-benzilaminopurina (BAP) em estacas radiculares de progênies de Gabirobeira (Campomanesia adamantium). As estacas radiculares foram obtidas de progênies de Gabirobeira de um e dois anos de idade. Estes foram segmentados em 5 cm de comprimento e apresentavam entre 1,90 a 3,22 mm de diâmetro, imersos nas concentrações: 0.0; 1.0; 2.0 e 4.0 mg L-1 de BAP por 15 segundos e plantados em bandejas contendo Bioplant®. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 2x4 (idades das estacas x concentrações de BAP), com quinze repetições por tratamento. Após 140 dias, foram avaliados o número de estacas com brotações, número de brotações, número de folhas e diâmetro da raiz principal. Estacas de raízes de progênies de dois anos de idade apresentaram melhor desenvolvimento. Menores concentrações de citocinina trouxeram melhores resultados de emissão e número de brotações das progênies de ambas as idades.

The Effect of Temperature and Growth Regulators on Callus Induction in Watermelon Anthers

HIGHLIGHTS Callogenesis was induced from watermelon anthers The auxin 2,4-D at 2.0 and 5.0 μM concentrations induced callus formation. Anthers' responses to the pre-treatment at 4 °C varied according to the watermelon genotype.

Abstract Callus induction is one of the pathways required for haploid plant regeneration through anther culture. Pollen viability, as well as the effect of growth regulators and cold pretreatment on anthers of two watermelon lines (Smile and Sugar Baby) to induce callus formation were herein evaluated. Pollen viability was estimated through the staining technique using 2% acetic carmine. Male flower buds were collected and disinfested to allow removal anthers. These anthers were placed on Murashige and Skoog medium, which was supplemented with 2,4-dichlorophenoxyacetic (2,4-D) at 0.0, 0.5, 1.0, 2.0 or 5.0 μM or with 6-benzylaminopurine at 0.0, 0.5, 1.0, 1.5, or 2.0 μM, in combination with 2.0 μM of 2,4-dichlorophenoxyacetic. Anthers were pretreated at 4 °C, for two days and then placed in vitro. Both watermelon lines provided high pollen viability rates (from 93 to 98%). The 2.0 and 5.0 μM concentrations of 2,4-D stimulated higher friable callus formation. The optimal concentration of 2,4-D was estimated at 3.78 μM and 4.17 μM, which had callus induction rates of 64% and 52%, respectively. The combination of 2.0 μM of 2,4-D and 6-benzylaminopurine did not lead to increased anther response to callus induction. The pre-treatment applied to flower buds at 4 °C enabled callus induction and the anther response to callus induction was genotype-dependent.

Costus root aqueous extract modulates rat liver toxicity, DNA damage, injury, proliferation alterations induced by plant growth regulator Ethephon

Ethephon (Ethrel®) is an ethylene-based plant growth regulator that used in agriculture and it has direct and indirect effects on human health, direct effect via its inhalation during usage in agriculture and indirect effect through the diet (Fruits and vegetables) that is sprayed with it. The current study aimed to examine the possible modifying effects of costus (Saussurea lappa) root aqueous extract against Ethephon induced liver toxicity, injury, DNA fragmentation and PCNA alterations in male rats. Fifty adult male rats were divided into 5 groups (1st, control; 2nd, Costus; 3rd, Ethephon; 4th, Post treated Ethephon with costus; 5th, self-healing Ethephon). Current results revealed that; a significant increase in aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), liver injury, DNA damage and PCNA expressions in Ethephon group when compared with control group. In contrast; a significant decrease in albumin and total proteins in Ethephon group when compared with control group. Treatment of rats with costus after Ethephon improved these alterations as compared with Ethephon self-healing. So, it could be concluded that costus root extract worth to be considered as a natural substance for ameliorating the hepatic toxicity induced by plant growth regulator Ethephon.

The era of nitric oxide in plant biology: Twenty years tying up loose ends.

Nitric oxide (NO) is an essential signal molecule to maintain cellular homeostasis in uni and pluricellular organisms. Conceptually, NO intervenes as much in sustaining basal metabolic processes, as in firing cellular responses to changes in internal and external conditions, and also in guiding the return to basal conditions. Behind these unusual capabilities of NO is the chemistry of this molecule, an unstable, reactive, free radical and short half-life gas. It is a lipophilic molecule that crosses all the barriers that biological membranes can impose. The extraordinary impact that the elucidation of physiological processes regulated by NO has had on plants, is comparable to the consequences of the discovery in 1986 that NO is present in animal tissues, and the following deep studies that demonstrated its biological activity regulating blood pressure. In this review, we have summarized and discuss the main discoveries that have emerged at Mar del Plata University over the past 20 years, and that have contributed to understand part of the biology of NO in plants. Besides, these findings are put in context with the progress made by other research groups, and in perspective, emphasizing that the history of NO in plants has just begun.

Effect of trinexapac-ethyl on sugarcane varieties / Efeito do trinexapac-ethyl em variedades de cana-de -açúcar

Growth regulators have been widely employed as maturation inducers in the sugarcane crop, as an agricultural strategy. However, the response of varieties to the use of these compounds has been poorly studied, mainly in cerrado (savannah-like biome) areas occupied by the crop. This study was carried out to examine the effects of trinexapac-ethyl on important morphological characteristics of sugarcane varieties. The experiment was set up as a randomized block design with a 4 × 2 factorial arrangement consisting of four varieties (RB83-5054, SP80-1816, RB96-6928, and RB85-5156) associated or unassociated with application of trinexapac-ethyl (375 g L­1 of the a.i. ha­1), with four replicates. The ripener was applied at 126, 178, and 228 days after planting (DAP) the first-cycle sugarcane, using the dose of 125 g L­1 a.i. ha­1 per application. Upon harvest, which occurred at 243 DAP, we determined the number of stalks per meter, weight of 30 stalks without top, internode length, number of internodes per stalk, and yield of sugarcane stalks. Ripener application increased the number of stalks in varieties RB96-6928 and RB83-5054 and the weight of 30 stalks in varieties RB96-6928 and RB83-5054 and SP80-1816; reduced internode length in varieties RB85-5156 and RB83-5054; and increased stalk yield per hectare in varieties RB96-6928 and RB83-5054, but did not increase the number of internodes per stalk in any of the tested varieties. The variables number of stalks, stalk weight, internode length, and stalk yield responded in a genotype-dependent manner to the application of trinexapac-ethyl.

O uso de reguladores de crescimento como indutores da maturação em cana-de-açúcar tem sido uma prática agrícola bastante empregada. Entretanto, a resposta das variedades à utilização desses compostos tem sido pouco estudada, principalmente em áreas de cerrado ocupadas pela cultura. O objetivo deste estudo foi avaliar os efeitos do trinexapac-ethyl em características morfológicas importantes para a produtividade de variedades de cana-de-açúcar. O delineamento experimental utilizado foi o de blocos casualizados em esquema fatorial 4 x 2, sendo quatro variedades (RB83-5054, SP80-1816, RB96-6928 e RB85-5156), combinadas com e sem aplicação de trinexapac-ethyl (375 g L-1 do i.a. ha-1) e quatro repetições. A aplicação do maturador ocorreu aos 126, 178 e 228 dias após o plantio (DAP) da cana planta, com dose de 125 g L-1 i.a. ha-1 por vez. Por ocasião da colheita, realizada aos 243 DAP, foram avaliados o número de colmos por metro, massa de 30 colmos sem ponteiro, comprimento de entrenós, número de entrenós por colmo e produtividade de colmos de cana-de-açúcar. Verificou-se que a aplicação do maturador incrementou o número de colmos para as variedades RB96-6928 e RB83-5054, a massa de 30 colmos para as variedades RB96-6928 e RB83-5054 e SP80-1816, maior redução no comprimento de entrenós para as variedades RB85-5156 e RB83-5054 e maior aumento na produção de colmos por hectare para as variedades RB96-6928 e RB83-5054, mas não aumentou o número de entrenós por colmo nas variedades testadas. A resposta das variáveis: número de colmos, massa de colmos, comprimento dos entrenós e produtividade de colmos à aplicação do trinexapac-ethyl mostrou-se genótipo dependente.

Responses of the weed Bidens pilosa L. to exogenous application of the steroidal saponin protodioscin and plant growth regulators 24-epibrassinolide, indol-3-acetic acid and abscisic acid.

The exogenous application of plant hormones and their analogues has been exploited to improve crop performance in the field. Protodioscin is a saponin whose steroidal moiety has some similarities to plant steroidal hormones, brassinosteroids. To test the possibility that protodioscin acts as an agonist or antagonist of brassinosteroids or other plant growth regulators, we compared responses of the weed species Bidens pilosa L. to treatment with protodioscin, brassinosteroids, auxins (IAA) and abscisic acid (ABA). Seeds were germinated and grown in agar containing protodioscin, dioscin, brassinolides, IAA and ABA. Root apex respiratory activity was measured with an oxygen electrode. Malondialdehyde (MDA) and antioxidant enzymes activities were assessed. Protodioscin at 48-240 µm inhibited growth of B. pilosa seedlings. The steroidal hormone 24-epibrassinolide (0.1-5 µm) also inhibited growth of primary roots, but brassicasterol was inactive. IAA at higher concentrations (0.5-10.0 µm) strongly inhibited primary root length and fresh weight of stems. ABA inhibited all parameters of seedling growth and also seed germination. Respiratory activity of primary roots (KCN-sensitive and KCN-insensitive) was activated by protodioscin. IAA and ABA reduced KCN-insensitive respiration. The content of MDA in primary roots increased only after protodioscin treatment. All assayed compounds increased APx and POD activity, with 24-epibrassinolide being most active. The activity of CAT was stimulated by protodioscin and 24-epibrassinolide. The results revealed that protodioscin was toxic to B. pilosa through a mechanism not related to plant growth regulator signalling. Protodioscin caused a disturbance in mitochondrial respiratory activity, which could be related to overproduction of ROS and consequent cell membrane damage.

Nitrogen supply associated with the application of trinexapac-ethyl in upland rice irrigated by sprinkler / Fornecimento de nitrogênio associado a aplicação de etil-trinexapac em arroz de terras altas irrigado por aspersão

The lodging of rice plants significantly increases the losses of this crop. Lodging is caused by the inadequate management of water and fertilizers, particularly nitrogenous fertilizers. The use of growth regulators causes a reduction in plant height and consequently lodging, and may reduce harvest losses. The objective of this study was to evaluate nitrogen (N) doses with and without application of plant growth regulator in upland rice irrigated by a sprinkler system. The experimental design consisted of randomized blocks arranged in a 4 × 2 factorial design with four replicates. The treatments consisted of four N doses (0, 40, 80, and 120 kg ha-1) combined with the presence or absence of foliar application of a plant growth regulator. The application of 150 g ha-1 of trinexapac-ethyl at the flower differentiation stage reduced plant height and lodging. In addition, this treatment promoted increased 100-grain mass. The use of N doses in topdressing increased plant heights and grain yield. The plant growth regulator did not interfere with the milling yield of upland rice. Nitrogen fertilization in the topdressing did not interfere with the milling yield of upland rice irrigated by a sprinkler system.(AU)

O acamamento das plantas de arroz aumenta sensivelmente as perdas dessa cultura, que é ocasionado pelo fornecimento de água e fertilizantes, principalmente os nitrogenados, manejados de forma inadequada. O uso de reguladores vegetais propicia redução na altura de plantas e consequentemente no acamamento, podendo minimizar as perdas na colheita. O objetivo foi avaliar doses de nitrogênio (N) com e sem a aplicação de regulador vegetal em arroz de terras altas irrigado por aspersão. O delineamento experimental utilizado foi o de blocos casualizados, disposto em esquema fatorial 4 × 2, com quatro repetições. Os tratamentos foram constituídos por quatro doses de N em cobertura (0, 40, 80 e 120 kg ha-1) combinadas com ou sem aplicação de regulador vegetal. A aplicação de 150 g ha-1 de etil-trinexapac, por ocasião da diferenciação floral, reduz a altura de plantas e o acamamento, e promove aumento da massa de 100 grãos. O uso de doses de N em cobertura aumenta a altura de plantas e incrementa a produtividade de grãos. O regulador vegetal interfere pouco no rendimento de engenho do arroz de terras altas. A adubação nitrogenada em cobertura praticamente não interfere no rendimento de engenho do arroz de terras altas irrigado por aspersão.(AU)

Nitrogen supply associated with the application of trinexapac-ethyl in upland rice irrigated by sprinkler / Fornecimento de nitrogênio associado a aplicação de etil-trinexapac em arroz de terras altas irrigado por aspersão

The lodging of rice plants significantly increases the losses of this crop. Lodging is caused by the inadequate management of water and fertilizers, particularly nitrogenous fertilizers. The use of growth regulators causes a reduction in plant height and consequently lodging, and may reduce harvest losses. The objective of this study was to evaluate nitrogen (N) doses with and without application of plant growth regulator in upland rice irrigated by a sprinkler system. The experimental design consisted of randomized blocks arranged in a 4 × 2 factorial design with four replicates. The treatments consisted of four N doses (0, 40, 80, and 120 kg ha-1) combined with the presence or absence of foliar application of a plant growth regulator. The application of 150 g ha-1 of trinexapac-ethyl at the flower differentiation stage reduced plant height and lodging. In addition, this treatment promoted increased 100-grain mass. The use of N doses in topdressing increased plant heights and grain yield. The plant growth regulator did not interfere with the milling yield of upland rice. Nitrogen fertilization in the topdressing did not interfere with the milling yield of upland rice irrigated by a sprinkler system.

O acamamento das plantas de arroz aumenta sensivelmente as perdas dessa cultura, que é ocasionado pelo fornecimento de água e fertilizantes, principalmente os nitrogenados, manejados de forma inadequada. O uso de reguladores vegetais propicia redução na altura de plantas e consequentemente no acamamento, podendo minimizar as perdas na colheita. O objetivo foi avaliar doses de nitrogênio (N) com e sem a aplicação de regulador vegetal em arroz de terras altas irrigado por aspersão. O delineamento experimental utilizado foi o de blocos casualizados, disposto em esquema fatorial 4 × 2, com quatro repetições. Os tratamentos foram constituídos por quatro doses de N em cobertura (0, 40, 80 e 120 kg ha-1) combinadas com ou sem aplicação de regulador vegetal. A aplicação de 150 g ha-1 de etil-trinexapac, por ocasião da diferenciação floral, reduz a altura de plantas e o acamamento, e promove aumento da massa de 100 grãos. O uso de doses de N em cobertura aumenta a altura de plantas e incrementa a produtividade de grãos. O regulador vegetal interfere pouco no rendimento de engenho do arroz de terras altas. A adubação nitrogenada em cobertura praticamente não interfere no rendimento de engenho do arroz de terras altas irrigado por aspersão.

Gibberellic acid combined with hand pollination increases 'Red' and 'Lessard Thai' sugar apple fruit quality and produced parthenocarpic 'Gefner' atemoya fruits / Ácido giberélico associado com a polinização manual incrementa a qualidade dos frutos em anonáceas e produz frutos partenocárpicos em atemoieira 'Gefner'

The present research aimed to evaluate the effect of applying gibberellic acid (GA3) with hand (HP) or natural pollination (NP) on fruit set and the fruit quality of ‘Red and ‘Lessard Thai sugar apple and ‘Gefner atemoya fruits.This study was performed in an experimental orchard located in Homestead, Florida, USA. The experimental design included randomized blocks, with eight treatments, four replicates and four plants per plot. Treatments included: (1) HP; (2) HP + 10 mg L-1 GA3; (3) HP + 100 mg L-1 GA3; (4) HP + 1,000 mg L-1 GA3; (5) NP; (6) NP + 10 mg L-1 GA3; (7) NP + 100 mg L-1 GA3 and (8) NP + 1,000 mg L-1 GA3. The HP plus 1,000 mg L-1 GA3 promoted fruit setting above 90% over the 14 weeks for all genotypes evaluated. Significant increments for length and total fruit weight were observed. ‘Red sugar apple and atemoya had a reduced number of seeds per fruit. The NP plus GA3 (1,000 mg L-1) was effective in producing high quality seedless ‘Gefner atemoya fruits. This investigation demonstrated that GA3 plus hand pollination produced high quality sugar apple and atemoya seeded fruits and in association with natural pollination promoted seedless ‘Gefneratemoya fruits.(AU)

O presente trabalho teve como objetivo avaliar o efeito da aplicação de ácido giberélico (GA3) associado com e sem polinização artificial, no pegamento e na qualidade de frutos das pinheiras ‘Red e ‘Lessard Thai e da atemoieira‘Gefner. O experimento foi realizado em pomar localizado em Homestead, EUA. O delineamento experimental foi em blocos casualizados, com oito tratamentos, quatro repetições e quatro plantas por parcela. Os tratamentos utilizados neste experimento foram: 1) Polinização Artificial (PA); 2) PA + 10 mg L-1 GA3; 3) PA + 100 mg L-1 GA3; 4) PA + 1000 mg L-1 GA3; 5) Polinização natural (PN); 6) PN + 10 mg L-1 GA3; 7) PN + 100 mg L-1 GA3; e 8) PN + 1000 mg L-1 GA3. A PA combinada com a concentração de 1000 mg L-1 de GA3 promoveu o estabelecimento de frutos acima de 90% durante as 14 semanas de avaliação para todos os genótipos avaliados. Incrementos significativos para o comprimento e peso dos frutos também foram observados a variedade de pinha “Red” e a atemoia, em que apresentaram redução no número total de sementes.A PN em associação com GA3 (1000 mg L-1) foi eficaz na produção de frutos sem sementes de alta qualidade em atemóia ‘Gefner. Estes dados mostram que o GA3, combinado com a polinização manual, produziu frutos com semente de alta qualidade e, em associação com a polinização natural, promoveu frutos sem sementes em atemóia ‘Gefner.(AU)

Gibberellic acid combined with hand pollination increases 'Red' and 'Lessard Thai' sugar apple fruit quality and produced parthenocarpic 'Gefner' atemoya fruits / Ácido giberélico associado com a polinização manual incrementa a qualidade dos frutos em anonáceas e produz frutos partenocárpicos em atemoieira 'Gefner'

ABSTRACT: The present research aimed to evaluate the effect of applying gibberellic acid (GA3) with hand (HP) or natural pollination (NP) on fruit set and the fruit quality of 'Red' and 'Lessard Thai' sugar apple and 'Gefner' atemoya fruits.This study was performed in an experimental orchard located in Homestead, Florida, USA. The experimental design included randomized blocks, with eight treatments, four replicates and four plants per plot. Treatments included: (1) HP; (2) HP + 10 mg L-1 GA3; (3) HP + 100 mg L-1 GA3; (4) HP + 1,000 mg L-1 GA3; (5) NP; (6) NP + 10 mg L-1 GA3; (7) NP + 100 mg L-1 GA3 and (8) NP + 1,000 mg L-1 GA3. The HP plus 1,000 mg L-1 GA3 promoted fruit setting above 90% over the 14 weeks for all genotypes evaluated. Significant increments for length and total fruit weight were observed. 'Red' sugar apple and atemoya had a reduced number of seeds per fruit. The NP plus GA3 (1,000 mg L-1) was effective in producing high quality seedless 'Gefner' atemoya fruits. This investigationdemonstratedthat GA3 plus hand pollination produced high quality sugar apple and atemoya seeded fruits and in association with natural pollination promoted seedless 'Gefner'atemoya fruits.

RESUMO: O presente trabalho teve como objetivo avaliar o efeito da aplicação de ácido giberélico (GA3) associado com e sem polinização artificial, no pegamento e na qualidade de frutos das pinheiras 'Red' e 'Lessard Thai' e da atemoieira'Gefner'. O experimento foi realizado em pomar localizado em Homestead, EUA. O delineamento experimental foi em blocos casualizados, com oito tratamentos, quatro repetições e quatro plantas por parcela. Os tratamentos utilizados neste experimento foram: 1) Polinização Artificial (PA); 2) PA + 10 mg L-1 GA3; 3) PA + 100 mg L-1 GA3; 4) PA + 1000 mg L-1 GA3; 5) Polinização natural (PN); 6) PN + 10 mg L-1 GA3; 7) PN + 100 mg L-1 GA3; e 8) PN + 1000 mg L-1 GA3. A PA combinada com a concentração de 1000 mg L-1 de GA3 promoveu o estabelecimento de frutos acima de 90% durante as 14 semanas de avaliação para todos os genótipos avaliados. Incrementos significativos para o comprimento e peso dos frutos também foram observados a variedade de pinha "Red" e a atemoia, em que apresentaram redução no número total de sementes.A PN em associação com GA3 (1000 mg L-1) foi eficaz na produção de frutos sem sementes de alta qualidade em atemóia 'Gefner. Estes dados mostram que o GA3, combinado com a polinização manual, produziu frutos com semente de alta qualidade e, em associação com a polinização natural, promoveu frutos sem sementes em atemóia 'Gefner'.

In Vitro Proliferation of Female Buds for Induction of Somatic Embryogenesis from False Horn Plantain (AAB, cv. Curraré).

Most cultivated bananas (Musa spp.) are polyploids, and their fruits are seedless and propagated exclusively vegetatively; however, they can also be cloned by micropropagation techniques, viz., direct organogenesis (DO) or somatic embryogenesis (SE). Banana indirect SE (ISE), with an embryogenic callus phase, is possible using young male or female flowers as direct explant depending on the genotype or shoot tips (scalps). For the False Horn Plantain, cv. Curraré (AAB, plantain subgroup), which has a degenerating male bud, female flowers are used to regenerate plants through ISE. Here, a protocol for increasing the number of initial explant material from a single mother plant and its embryogenic response is described. For those purposes, hands with young female buds are in vitro proliferated in the presence of 1 µM indole-3-acetic acid and 2.5 µM thidiazuron. Friable embryogenic cultures, here called ISE-2, obtained from the new proliferative secondary female bud clusters are initiated on medium containing auxins. Embryogenic suspensions are then established from the ISE-2 cultures. Regeneration of plants is achieved from embryogenic suspensions after plating on semisolid medium free of plant growth regulators; greenhouse acclimatized plantlets are ready for banana farming. This study demonstrates that proliferative female buds are a proper choice for ISE.

Agronomic performance of sesame (Sesamum indicum L. ) genotypes under phytostimulant application / Desempenho agronômico de genótipos de gergelim (Sesamum indicum L. ) sob aplicação de fitoestimulante

Sesame (Sesamum indicum L.) is one of the oldest cultivated plant species and become an important alternative to reduce food deficiency in low income populations. Growth regulators influence protein metabolism and may increase the rate of enzyme synthesis involved in the process of seed germination, rooting, flowering, and fruiting of plants. This study aimed to evaluate the agronomic performance of sesame genotypes under the influence of the bioregulator Stimulate® in two agricultural years in the northeastern region of Brazil. The experiment was carried out in the dry and wet seasons (agricultural years 2014 and 2015, respectively) in the city of Garanhuns in the state of Pernambuco. The experiment was carried out in randomized blocks using four genotypes of sesame (BRS SEDA, CNPA G4, Lineage 1, and Lineage 2), with and without application of the phytostimulant (Stimulate®). Phytostimulant application did not influence root length. However, it resulted in an increase in the number of fruits per plant, and for genotypes Lineage 1 and Lineage 2, an increase in the content of chlorophyll A and B. Thus, the application of phytostimulant increases the yield of sesame; however, the response to phytostimulant application varies with the genotype and growth conditions.

O Gergelim (Sesamum indicum L.) é uma das espécies vegetais mais antigas cultivadas pelo homem, e tem se tornado uma alternativa importante para minimizar o agravante quadro de carência alimentar das populações de baixa renda. Os reguladores de crescimento influenciam o metabolismo proteico, podendo aumentar a taxa de síntese de enzimas envolvidas no processo de germinação das sementes, enraizamento, floração e frutificação das plantas. Desta forma este trabalho visou avaliar o desempenho agronômico de genótipos de gergelim sob a influência da aplicação do biorregulador Stimulate® em dois anos agrícolas nas condições do semiárido nordestino. O experimento foi realizado nos anos agrícolas, na estação chuvosa (2014) e na estação seca (2015) na cidade de Garanhuns-PE. O experimento foi conduzido em blocos casualizados, com a utilização de quatro genótipos de gergelim (BRS SEDA, CNPA G4, Linhagem 1 e Linhagem 2), com e sem aplicação do fitoestimulante (Stimulate®). A aplicação do fitoestimulante não influenciou no comprimento de raiz. Porém, proporcionou aumento no número de frutos por planta e nos genótipos Linhagem 1 e Linhagem 2 promoveu também aumento no teor de clorofila A e B. A aplicação do fitoestimulante aumenta a produtividade, entretanto, a resposta à aplicação vai variar com o genótipo e condições de cultivo. A aplicação de fitoestimulante aumenta a produtividade na cultura do gergelim, no entanto, a resposta à aplicação irá variar com o genótipo e condições de crescimento.

Pre-germination treatment in granadilla (Passiflora ligularis) seeds / Tratamentos pré-germinativos em sementes de granadilla (Passiflora ligularis)

A granadilla é um maracujá doce, sendo os frutos consumidos in natura. O principal método de propagação de mudas é via sexuada, porém com baixa taxa de germinação devido a dormência encontrada nas sementes. Diante do exposto, objetivou-se com o presente trabalho avaliar o ácido giberélico e temperatura na germinação de sementes de granadilla. O experimento foi realizado em Laboratório de sementes e mudas. Os frutos de granadilla foram adquiridos de fruticultor idôneo do município, sendo previamente selecionados, seccionados e retiradas as sementes para posterior montagem do experimento. O delineamento experimental utilizado foi inteiramente casualizado, em esquema fatorial 2 (temperaturas, sendo 25 ºC constante, e 20-30 ºC alternados) x 2 (100 mgL-1 de ácido giberélico e ausência), contendo 4 repetições e 50 sementes por repetição. Avaliaram-se a cada dois dias, até sessenta dias a percentagem de germinação, índice de velocidade de germinação, tempo médio de germinação, altura (mm) e biomassa seca (mg) de plântulas. Melhores resultado foram obtidos para as sementes de granadilla foram verificados com a utilização de 100 mg L-1 de GA3 e em temperatura alternada de 20-30 ºC. Menor tempo médio de germinação (14 dias) foi obtido quando as sementes foram tratadas com ácido giberélico. Maior percentagem de germinação de sementes de granadilla foi 53,2 % na temperatura de 20-30 ºC alternado.(AU)

The granadilha is a sweet passion fruit, and the fruit is consumed while fresh. The method for seedling propagation is via sexual, but germination rates are low due to dormancy found in the seeds. The aim of the present study was to evaluate gibberellic acid and temperature in granadilha seed germination. The experimental design was completely randomized in a factorial 2 (temperature, 25 °C constant, and alternating 20-30 °C) x 2 (100 mg L-1 of gibberellic acid and absence), containing 5 replications and 80 seeds per repetition. They were evaluated every two days, until sixty days germination percentage, for germination speed index, germination velocity time, height (mm) and dry weight (mg) of seedlings. Best results were obtained for the granadilha seeds were found using 100 mg L-1 of GA3 and alternating temperatures of 20-30 °C. The highest percentage of granadilha seed germination was 53.2% at the temperature of 20-30 °C alternating.(AU)