Analysis of Grading Evaluation Standard of Ophiopogonis Radix from Sichuan Province / 中国实验方剂学杂志

Objective::To investigate the correlation between the characteristics and internal quality of Ophiopogonis Radix from Sichuan province through various quality evaluation, and provide reference for the formulation of grading standard of this herb. Method::For 28 batches of Ophiopogonis Radix, the characters, microscopic characteristics, thin-layer chromatography (TLC), the content of moisture, ash content, acid insoluble ash content, residues of sulfur dioxide, heavy metals, hazardous elements and paclobutrazol, water-soluble extract, contents of total saponins and three major components [ophiopogonin D (OPD), methylophiopogonanone A (MPOA) and methylophiopogonanone B (MPOB)] were determined.The relationships between various indicators and the grade of Ophiopogonis Radix were analyzed. Result::Ophiopogonis Radix exhibited specific properties in characters, microscopic characteristics and TLC.The contents of impurity, moisture, total ash, acid-insoluble ash and water-soluble extract existed differences in four grades of Ophiopogonis Radix from Sichuan province.For grade Ⅰ, grain number was 80-120 grains per 50 g, the moisture content was 11.1%-14.9%, total ash content was 1.6%-2.1%, acid-insoluble ash content was 0.03%-0.14%, water-soluble extract content was 77.0%-86.5%.For grade Ⅱ, grain number was 120-160 grains per 50 g, the moisture content was 13.1%-14.2%, total ash content was 1.3%-2.2%, acid-insoluble ash content was 0.06%-0.22%, water-soluble extract content was 75.9%-83.3%.For grade Ⅲ, grain number was 160-300 grains per 50 g, the impurity was 0.2%-8.4%, the moisture content was 12.6%-14.0%, total ash content was 1.2%-1.5%, acid-insoluble ash content was 0.06%-0.22%, water-soluble extract content was 74.0%-86.5%.For grade Ⅳ, grain number was 80-300 grains per 50 g, impurity was 1.2%-22.6%, the moisture content was 13.0%-15.4%, the total ash content was 1.4%-2.0%, acid-insoluble ash content was 0.03%-0.15%, water-soluble extract content was 79.8%-85.2%. Conclusion::It is reasonable and feasible to classify the grade of Ophiopogonis Radix from Sichuan province according to the appearance characteristics such as the grain number per 50 g and internal indexes such as impurity and water-soluble extract, which can be used as a reference for grading standards of Ophiopogonis Radix from Sichuan province.

Determination of Paclobutrazol Residue in Ophiopogon japonicus from Sichuan by the QuEChERS Combined with GC-MS/ MS-internal Standard Detection / 中国药房

OBJECTIVE： To establish a method for measuring the paclobutrazol residue in Ophiopogon japonicus from Sichuan and detect the quality of O. japonicus from Sichuan from different sources. METHODS： Totally 50 batches of samples were collected from different origin places， commercial markets and manufacturers. The sample pretreatment method was QuEChERS method， .ie the sample was extracted by aqueous acetonitrile， salted out by QuEChERS extract package （containing anhydrous magnesium sulfate and anhydrous sodium acetate）， the extract solution was purified by QuEChERS purification package （containing anhydrous magnesium sulfate， N-propyl ethylenediamine， octadecylsilane chemically bonded silica， silica gel， graphitized carbon black） and then added into internal standard triphenyl phosphate. The paclobutrazol residue in O. japonicus from Sichuan was determined by GC-MS/MS. The determination was performed on DB-5MS column. The temperature programming was adopted， and the detector was triple quadrupole MS detector. The initial flow rate of carrier gas was 1.3 mL/min； acquisition mode was MRM. Injection method was splitless injection. RESULTS： The linear range of paclobutrazol was 1.01-505 ng/mL （r＝    0.999 7）. RSDs of precision， stability （24 h） and repeatability tests were 3.94％， 13.62％， 7.54％ （n＝6）， respectively. Average method recovery was 111.26％ （RSD＝5.43％， n＝9）. The paclobutrazol residue in 50 batches of sample were 0.02-2.72 mg/kg. CONCLUSIONS： Established method is simple， accurate， sensitive and reproducible. It also can be used for the determination of paclobutrazol residue in O. japonicus from Sichuan. The contents of paclobutrazol residue in O. japonicus from Sichuan from different sources are different greatly.

JcZFP8, a C2H2 zinc finger protein gene from Jatropha curcas, influences plant development in transgenic tobacco

Background: Jatropha curcas L., as an important strategic biofuel resource with considerable economic potential, has attracted worldwide attention. However, J. curcas has yet to be domesticated. Plant height, an important agronomic trait of J. curcas, has not been sufficiently improved, and the genetic regulation of this trait in J. curcas is not fully understood. Zinc finger proteins (ZFPs), a class of transcription factors, have previously been shown to play critical roles in regulating multiple aspects of plant growth and development and may accordingly be implicated in the genetic regulation of plant height in J. curcas. Results: In this study, we cloned JcZFP8, a C2H2 ZFP gene in J. curcas. We found that the JcZFP8 protein was localized in the nucleus and contained a conserved QALGGH motif in its C2H2 structure. Furthermore, ectopic expression of JcZFP8 under the control of the 35S promoter in transgenic tobacco resulted in dwarf plants with malformed leaves. However, when JcZFP8 was knocked out, the transgenic tobacco did not show the dwarf phenotype. After treatment with the gibberellic acid (GA) biosynthesis inhibitor paclobutrazol (PAC), the dwarf phenotype was more severe than plants that did not receive the PAC treatment, whereas application of exogenous gibberellin3 (GA3) reduced the dwarf phenotype in transgenic plants. Conclusions: The results of this study indicate that JcZFP8 may play a role in J. curcas plant phenotype through GA-related pathways. Our findings may help us to understand the genetic regulation of plant development in J. curcas and to accelerate breeding progress through engineering of the GA metabolic pathway in this plant. How to cite: Shi X,Wu Y, Dai T, et al. JcZFP8, a C2H2 zinc-finger protein gene from Jatropha curcas, influences plant development in transgenic tobacco.

Metabolic disturbance and phytochemical changes in Andrographis paniculata and possible action mode of andrographolide

Objective: To explore the effect of gibberellic acid (GA

Metabolic disturbance and phytochemical changes in Andrographis paniculata and possible action mode of andrographolide

Objective:To explore the effect of gibberellic acid (GA3) and its inhibitor paclobutrazol (PBZ)on chemical composition and their pharmacological effects on Andrographis paniculata (Burm.f.) Wall.ex Nees,and to clarify action mode of andrographolide.Methods:The chemical composition was extracted by sequential extraction with hexane,dichloromethane,ethyl acetate and methanol,respectively.Andrographolide and its derivatives were evaluated by HPLC.Moreover,the metabolic profiling was analyzed by GC-MS.Inhibitory effect of crude extracts was tested against Staphylococcus aureus using agar well diffusion method.Mode of action was tested against mutant yeast by spotting assay.Andrographolide were tested for their mode of action against eukaryotes.Results:Among different solvents,dichloromethane gave the highest yield of crude (3.58％ DW),with the highest andrographolide content (8.3 mg/g DW).The effect of plant hormone (10 mg/L GA3 or PBZ) on phytochemical variations and bioactivity of Andrographis paniculata was demonstrated.It was found that PBZ promoted sesquiterpene compounds about 3.5 times over than GA3 treatment.But inhibitory effect of extracts against Staphylococcus aureus was highest in GA3 treated plants;andrographolide and 14-deoxy-11,12-didehydroandrographolide contents were significantly higher than those of water or PBZ.It was found that there were 11 strains involving in ergosterol biosynthesis,V-ATPase activity and homeostasis,and superoxide detoxification process.In this regard,andrographollde might cause the damage on the lipid bilayer of yeast cell and plasma membrane by interfering ergosterol biosynthesis.Conclusions:It is found that GA3 promotes andrographolide and 14-deoxy-11,12-didehydroandrographolide content while PBZ promotes sesquiterpene content.Andrographolide might cause the damage on the lipid bilayer of yeast cell and plasma membrane by interfering ergosterol biosynthesis.It might also affect mitochondria electron transport chain,leading to the occurrence of ROS,which can further harm cell organelles.However,the library screening is the first step to investigate mode of action of andrographolide.

Chronic toxicity and carcinogenicity of paclobutrazol in SD rats / 中国职业医学

OBJECTIVE: To explore the chronic toxicity and carcinogenicity of paclobutrazol in SD rats. METHODS: Specific pathogen free SD rats at the age of weaning were randomly divided into control group and low-,medium-,and high-dose groups according the body weight,with 120 rats in each group,half male and half female. The study of combined chronic toxicity and carcinogenicity test in rats was carried out in 2 years by feeding the rats with paclobutrazol. The doses in the 4 groups were 0. 0,11. 7,48. 5 and 193. 9 mg·kg~(-1)·d~(-1) for female rats and 0. 0,13. 5,54. 2 and 241. 9 mg·kg~(-1)·d~(-1) for male rats. The body weight of rats was weighted during the experiment. The blood routine,blood biochemistry,organ coefficient and histopathology examinations were performed at the end of paclobutrazol exposure. The mortality and tumor incidence in rats were calculated. RESULTS: The decrease of body weights in female and male rats in dose groups was observed at 1-2 weeks after the experiment,compared with the same sex control group at the same time point( P < 0. 05).At the end of the exposure,the body weights of female and male rats in all three dose groups were lower than that in the same sex rats of control group( P < 0. 05). The mortality rates of female and male rats in the four groups were not significantly different( P > 0. 05). The brain organ coefficients of female rats in the three dose groups were higher than those female rats in the control group( P < 0. 05). The organ coefficients of liver,kidney and ovary of female rats in highdose group were higher than that of female rats in control group( P < 0. 05). The level of total bilirubin in male rats in the three dose groups was lower than that in control group( P < 0. 05). The organ coefficients of brain and lung in male rats in the medium-and high-dose groups were higher than that in the control group( P < 0. 05). The liver organ coefficient in male rats in the high-dose group was higher than that in the control group( P < 0. 05). A total of 244 rats had 402 spontaneous tumors with a tumor incidence rate of 50. 8%(244/480). The incidence of tumor in control,low-,mediumand high-dose groups were 61. 7%( 74/120), 42. 5%( 51/120), 50. 0%( 60/120) and 49. 2%( 59/120)respectively. There was no statistical significance in the incidence of tumors in three dose groups compared with that of the control group. CONCLUSION: Under the dose conditions designed in this study,the lowest observed adverse effect level of paclobutrazol were 11. 7 and 13. 5 mg · kg~(-1)· d~(-1) in females and males respectively. Paclobutrazol was not found carcinogenic to SD rats.

Comprehensive evaluation of use of paclobutrazol in the cultivation of Ophiopogonis radix based on safety and efficacy / 中国药学杂志

OBJECTIVE: To provide a theoretical basis for scientific and rational use of paclobutrazol in the production of Ophiopogonis Radix. METHODS: Different concentrations of paclobutrazol were applied to Ophiopogonis Radix plants, and medicinal samples were colleted. The efficacy of Ophiopogonis Radix were comprehensively analyzed from the appearance of the herb and the contents of three kinds of effective components: flavonoids, saponins, and polysaccharides. Residues of paclobutrazol were detected. The effect of paclobutrazol use on the safety of Ophiopogonis Radix was evaluated according to the acceptable daily intake (ADI) of paclobutrazol in the GB2763-2014 and the amount of usage of paclobutrazol required by Chinese Pharmacopoeia. RESULTS: Paclobutrazol had no significant effects on the Ophiopogonis Radix appearance; and the contents of polysaccharides and flavonoid were increased in varying degrees, and saponins content were decreased. The daily intake of paclobutrazol was far less than the ADI (0.1 mg·kg-1 × body weight) when calculated using the maximum residue of paclobutrazol at the usage of 3 kg·acres-1 and the maximum usage amount of Ophiopogonis Radix in Chinese Pharmacopoeia. CONCLUSION: Paclobutrazol can be used within limits according to the actual situation in Ophiopogonis Radix production.

Controle químico da mancha bacteriana em mudas de tomate para processamento industrial / Chemical control of bacterial spot in seedlings of tomato for industrial processing

Com o objetivo de avaliar opções de produtos para o controle da mancha bacteriana em mudas de tomate, foram realizados dois ensaios independentes, em viveiro comercial, no município de Rio Verde ­ GO, nos períodos de novembro a dezembro de 2009. Os experimentos foram conduzidos em delineamento experimental inteiramente casualizado com três repetições, utilizando o híbrido Heinz 9553. A parcela foi representada por 450 mudas em uma bandeja comercial. O primeiro ensaio consistiu nos tratamentos: 1 - testemunha; 2 - oxicloreto de cobre; 3 - hidróxido de cobre; 4 - acibenzolar-S-metil; 5 - metiram + piraclostrobina; 6 - famoxadona + mancozebe; 7 - cloreto de benzalcônio. O segundo ensaio consistiu nos mesmos tratamentos do primeiro ensaio acrescidos da aplicação do regulador de crescimento - paclobutrazol. As aplicações foram realizadas via pulverização foliar, utilizando pulverizador costal de barra com pressão constante. Após 29 dias da semeadura, o isolado EH 2008-13 de X. perforans, foi inoculado por meio da imersão das mudas em bandeja. A severidade da mancha bacteriana foi avaliada em 15 folíolos de cada parcela aos 16 dias após a inoculação. Não houve diferenças significativas no primeiro ensaio, mas detectou-se diferença significativa no segundo onde houve a aplicação do regulador de crescimento (P= 0,001). Os tratamentos acibenzolar-S-metil e famoxadona + mancozebe apresentaram valores médios de severidade inferiores à testemunha, no entanto, não diferiram significativamente dela. O tratamento metiram + piraclostrobina apresentou maior severidade da mancha bacteriana, não demonstrando ser eficaz no controle da doença em mudas nas condições testadas neste ensaio. Os resultados indicam possível efeito do regulador de crescimento sobre a ação dos produtos testados.

With the aim of evaluate chemical options to the control of bacterial spot in tomato seedlings, two independent experiments were carried out at a commercial tomato nursery in Rio Verde, Goiás, during the periods of November to December of 2009. The hybrid Heinz 9553 was used. The trials were in a completely randomized design with three replications. The plots were represented by a commercial plantlet trays of 450 cells. The treatments were: 1 - control; 2 - copper oxicloreto; 3 - copper hydroxide; 4 - acibenzolar-S-methyl; 5 - metiram + pyraclostrobin, 6 - famoxadone + mancozebe ; 7 ­ benzalkonium chloride. The experiments differed as for the paclobutrazol application, in the second experiment. The products were applied by using a CO2 portable sprayer with constant pressure. The inoculation occurred at 29 days after sowing, with isolated EH 2008-13 of Xanthomonas perforans which was originated from Rio Verde. The aerial part of the plantlets were immersed during 1 minute in a 18 L of the bacterial suspension placed in a large plastic tray. Disease severity was evaluated on 15 leaflets per plot at 16 days after inoculation. It was expressed in terms of average percentage of foliar area with symptoms by using the computational program Quant 2002. For the experiment without use of growth regulator there were not significant differences among the treatments. Despite presenting significant differences, in the for the paclobutrazol application, except for treatment metiram + pyraclostrobin, which resulted in the higher disease value, all treatments were not significantly different from the check-control. In that trial, acibenzolar-S-methyl following by famoxadone + mancozebe, were the only ones that presented inferior values comparing with the check-control, however not being significantly different. It can be inferred that interaction between the growth regulator and some treatments should exist.

Response of Pigeon Pea Landraces [Cajanus cajan (L.) Millsp.] to Exogenous Application of Plant Growth Regulators.

Aim: Optimizing plant growth regulators in the manipulation of growth physiology, development and seed yield of pigeon pea landraces is cardinal, especially as it complements other improvement techniques. The research was aimed at evaluating the effect of IAA, NAA and paclobutrazol singly and in combination, but especially paclobutrazol in reducing plant height. Methods: Thirty (30) seeds each of brown “Fiofio” [Cajanus cajan (L.) Millsp.] were soaked in 0, 100, and 150mg/l concentration of IAA, NAA, paclobutrazol, paclobutrazol + IAA and paclobutrazol + NAA, respectively for 48 hours. Results: Results obtained revealed that treating pigeon pea seeds with paclobutrazol caused reduction in plant height and inter-node length, which did not translate to higher yield. However, plants raised from pigeon pea seeds soaked in 100 and 150 mg/l paclobutrazol + NAA did excellently well in both yield and yield – related traits. Conclusion: The implication of these findings is that though treating seeds with paclobutrazol caused significant reduction in plant height and increased branch numbers, it needed to interact with NAA to cause holistic improvement, especially in seed yield.

Reguladores de crescimento e seus efeitos sobre a qualidade fisiológica de sementes e crescimento de plântulas de crotalária / Growth regulators and its effect on the physiological quality of seeds and growth seedlings of sunn hemp

Informações referentes à utilização de reguladores de crescimento em crotalária ainda são escassas, notadamente sobre a qualidade fisiológica de sementes e o crescimento de plântulas. Nesse aspecto, o conhecimento do produto e da dose de aplicação se destaca como fatores relevantes na produção de sementes de boa qualidade. Este trabalho objetivou avaliar o efeito da aplicação foliar de reguladores de crescimento (cloreto de mepiquat, etil-trinexapac e paclobutrazol) em diferentes doses (0; 75; 150; 225 e 300 g ha-1), sobre a qualidade fisiológica de sementes e o crescimento de plântulas de Crotalaria juncea cultivada em sistema plantio direto. Os tratamentos foram dispostos em delineamento experimental de blocos ao acaso em esquema fatorial 3 x 5 (reguladores x doses de aplicação), com quatro repetições. Os resultados foram submetidos à análise de variância, com os reguladores de crescimento comparados pelo teste de Tukey e as doses por regressão polinomial. Não se recomenda a aplicação de cloreto de mepiquat na cultura da crotalária por reduzir o potencial de germinação das sementes e a biomassa fresca de plântula. O etil-trinexapac deve ser aplicado na dose de 300 g ha-1, com base na redução do grau de umidade e na condutividade elétrica das sementes, maior comprimento total de plântula e biomassa fresca de plântula. O paclobutrazol deve ser aplicado na dose de 75 g ha-1 , considerando o potencial e velocidade de germinação das sementes.

Information regarding the use of growth regulators in sunn hemp is still scarce, especially on the physiologic quality of seeds and growth seedlings. In this aspect, product knowledge and application rate stands out as relevant factors in production of quality seeds. This work aimed to evaluated the effect of the foliar application of growth regulators (mepiquat chloride, etil-trinexapac and paclobutrazol) in different rates (0; 75; 150; 225 and 300 g ha-1), on the physiological quality of seeds and growth seedlings of Crotalaria juncea cultivated in no-tillage system. The treatments were disposed in randomized complete block design in factorial scheme 3 x 5 (regulators x rates of application), with four replications. The results were submitted to the variance analysis, with the growth regulators compared by Tukey test and the rates for polynomial regression. Not if recommended the application of mepiquat chloride in sunn hemp culture by reducing the potential of seeds germination and dry biomass of seedlings. The etil-trinexapac must be applied in rate of 300 g ha-1, based on the reduction of moisture content and the electrical conductivity of seeds, the greater total length of seedlings and dry biomass of seedlings. The paclobutrazol must be applied in rate of 75 g ha-1, considering the potential and speed of seeds germination.

Growth retardants in wheat and its effect in physiological quality of seeds / Redutores de crescimento em plantas de trigo e seus efeitos na qualidade fisiológica de sementes

Plant lodging in wheat has been controlled through growth retardants. However, there is lack of information on the effect of these products on the physiological quality of seeds. The objective of this study was to evaluate the physiological quality of wheat seeds obtained under different rates and application times of three growth retardants. The trial was carried out in Viçosa-MG, from May to September 2005, in a factorial and hierarchical scheme, in randomized block design with four replications and a control treatment. The treatments consisted of 500, 1000 and 1500g ha-1 of chlormequat; 40, 80 and 120g ha-1 of paclobutrazol and 62.5, 125 and 187.5g ha-1 of trinexapac-ethyl applied at the 6 or 8 growth stage based on the scale of Feeks and Large, and a control treatment without growth retardant application. Leaf application of growth retardants as chlormequat, paclobutrazol and trinexapac-ethyl did not affect the germination and vigor of wheat seeds.

O acamamento de plantas na cultura do trigo tem sido controlado com o uso de redutores de crescimento. No entanto, há carência de informações sobre o efeito desses produtos na qualidade fisiológica de sementes. O objetivo deste estudo foi avaliar a qualidade fisiológica das sementes de trigo obtidas sob efeito de doses e épocas de aplicação de três redutores de crescimento. O experimento, conduzido em Viçosa, Minas Gerais, entre maio e setembro de 2005, foi instalado com tratamentos em esquema fatorial e hierárquico com uma testemunha, no delineamento em blocos casualizados, com quatro repetições. Os tratamentos foram 500, 1000 e 1500g ha-1 de clormequat; 40, 80 e 120g ha-1 de paclobutrazol e 62,5, 125 e 187,5g ha-1 de trinexapac-etil aplicados no estádio 6 ou 8 da escala Feeks e Large, mais uma testemunha sem aplicação de redutor. A aplicação foliar dos redutores de crescimento clormequat, paclobutrazol e trinexapac-etil não afeta a germinação e o vigor das sementes de trigo.

Inibidores de síntese de giberelinas e crescimento de mudas de mangueira 'Tommy Atkins' / Synthesis inhibitors of gibberellins and mango 'Tommy Atkins' seedlings growth

A mangicultura no semiárido brasileiro destaca-se pelos altos rendimentos, pela qualidade do fruto produzido e pela possibilidade de produção durante todo o ano, devido a condições climáticas e tecnologias para o manejo do crescimento vegetativo e da floração, com uso da irrigação, podas e retardantes vegetais. O paclobutrazol aplicado ao solo é utilizado no manejo da produção da mangueira na maioria dos pomares. Entretanto, há a necessidade de identificar retardantes vegetais que possam ser aplicados via foliar, de forma a minimizar os resíduos no solo e evitar o uso de quantidades inadequadas ao longo dos anos. Assim, este trabalho teve como objetivo avaliar retardantes vegetais aplicados via foliar na inibição do crescimento vegetativo de mudas de mangueira 'Tommy Atkins'. Prohexadione-Ca, etil-trinexapac e cloreto de chlormequat, aplicados via foliar, na dose de 1g i.a. planta-1, regulam o crescimento de ramos vegetativos, mas apresentam tempo diferenciado de atividade nas mudas, sendo 20 dias para prohexadione-Ca, 30 dias para cloreto de chlormequat e 45 dias para etil-trinexapac, nas condições em que o experimento foi conduzido.

The mango in the Brazilian semi-arid region stands out in the national scenario due to high yields and fruit quality, as well as to the possibility of all-year production due to climatic conditions and technologies which allow the management of plant growth and flowering through irrigation, pruning and use of plant growth regulators. Paclobutrazol applied to the soil is used for the production management of mangoes in most of the orchards. However, it is necessary to identify plant growth regulators which might be applied to the leaves, so as to minimize the risk of residues in the soil and to avoid inadequate application levels over several years. The present paper aimed at evaluating the effect of plant growth regulators applied to the leaves, regarding their efficiency for flowering management of mango 'Tommy Atkins'. Prohexadione-Ca, trinexapac-ethyl and chlormequat chloride at the dosage of 1.0 g a.i. plant-1 acts on the regulation of vegetative growth; the period of efficiency of the products applied to the leaves lasted 20 days for prohexadione-Ca, 30 days for chlormequat cloride, and 45 days for trinexapac-ethyl.

Efeito de paclobutrazol como regulador de crescimento e produção de flores de girassol em cultivo hidropônico / Effect of paclobutrazol as regulator of growth in production of flowers of sunflower in cultivo hidropônico

Objetivou-se neste trabalho estudar os efeitos de um regulador de crescimento (paclobutrazol) sobre o crescimento e a produção de flores de girassol em vasos, crescidos sob sistema hidropônico. Foram utilizados dois genótipos de girassol (BRS Oásis e Helio 358), combinados com seis doses de paclobutrazol (0;0,5;1;2;4 e 6 mg.L-1) e substrato inerte de sílica moída. A solução nutritiva foi a de Hoagland modificada (EPSTEIN & BLOOM, 2004) e as plantas foram mantidas sob aeração constante. Para avaliar os efeitos do paclobutrazol sobre o crescimento das plantas (altura final e diâmetro de capítulo), as variáveis foram submetidas à análise de variação (teste F), utilizando-se rotinas do sistema SAS/STAT , aplicando-se, para os valores significativos a 5 por cento de probabilidade e a regressão linear e não linear para a análise dos parâmetros aferidos, em função das doses do regulador de crescimento. A análise dos dados permitiu concluir que há efeito do paclobutrazol sobre o crescimento e sobre a produção de flores de girassol, reduzindo a altura final das plantas e o diâmetro dos capítulos, sendo que doses elevadas causaram deformações nas plantas e má formação nas flores. Helio 358 apresentou-se mais adequado para a produção ornamental, sendo melhor dose entre 1 e 2 mgL-1de paclobutrazol.

This work had the aim of studying the effects of a growth regulator (paclobutrazol) on the growth and the production of sunflowers in vases, with hidroponic solution. Two sunflower genotipes were used (BRS Oásis and Helio 358), combined with sixpaclobutrazol doses (0;0,5;1;2;4 and 6 mg.L-1) and inert substratum of silex ground. The nutritious solution was a Hoagland modified (EPSTEIN & BLOOM, 2004) and the plants were maintained under constant aeration. To evaluate the effects of the paclobutrazol on the growth of the plants (final height and head diameter), the variables were submitted to the variation analysis (F tests) , being used routines of the system SAS/STAT, being applied, for the significant values at 5 percent of probability and the lineal and not lineal regression for the analysis of the parameters checked, in function of the growth regulator doses. The analysis of the data allowed to conclude that there is effect of the paclobutrazol on the growth and on the production of sunflowers, reducing the final height of the plants and head diameter, and the high doses caused deformations in the plants and bad formation in the flowers. Helio 358 presented to be more adequate for the ornamental production, being the best dose between 1 and 2 mgL-1de paclobutrazol.