Improving the method for determining the physiological and sanitary potential of Gherkin seeds

Gherkin seeds usually show irregular physiological quality. Seed production requires fast and reliable tests to evaluate seed quality. Germination test is considered a recognized analysis method; however, seed technology has pursuit the improvement of vigor tests aiming the evaluation of seed's physiological potential. Thus, the objective of this work was to evaluate procedures to perform the test of accelerated aging and determine the physiological and sanitary potential of gherkin seeds. Four seed lots of cultivar Liso Calcuta were used in the study. To evaluate the initial physiological quality the water content was determined and germination and emergence tests, as well as indices of germination speed and emergence speed were used. The accelerated aging test was performed as traditionally and with saturated saline solution, with 48, 72 and 96 hours, at temperatures of 41oC and 45oC. After aging, the water content was determined, and seeds' germination and sanity tests were performed. The experiment was set under a completely random design in factorial 4x3x2 (lots x aging periods x temperatures). The standard accelerated aging test and the test with saturated saline solution at 41oC for 96 hours were efficient to evaluate the vigor of gherkin seeds. Saturated saline solution provides uniform water absorption and deterioration in gherkin seeds, allowing to discriminate seed lots in different vigor levels. The salinity test after accelerated aging with saline solution reduces the incidence of some fungi.

Phenolic compound production and biological activities from in vitro regenerated plants of gherkin (Cucumis anguria L. )

Background The effect of polyamines (PAs) along with cytokinins (TDZ and BAP) and auxin (IBA) was induced by the multiple shoot regeneration from leaf explants of gherkin (Cucumis anguria L.). The polyphenolic content, antioxidant and antibacterial potential were studied from in vitro regenerated and in vivo plants. Results Murashige and Skoog (MS) medium supplemented with 3% sucrose containing a combination of 3.0 µM TDZ, 1.0 µM IBA and 75 µM spermidine induced maximum number of shoots (45 shoots per explant) was achieved. Regenerated shoots elongated in shoot elongation medium containing 1.5 µM GA3 and 50 µM spermine. The well-developed shoots were transferred to root induction medium containing 1.0 µM IBA and 50 µM putrescine. Rooted plants were hardened and successfully established in soil with a 95% survival rate. Twenty-five phenolic compounds were identified by ultra-performance liquid chromatography (UPLC) analysis The individual polyphenolic compounds, total phenolic and flavonoid contents, antioxidant and antibacterial potential were significantly higher with in vitro regenerated plants than in vivo plants. Conclusions Plant growth regulators (PGRs) and PAs had a significant effect on in vitro plant regeneration and also a biochemical accumulation of flavonols, hydroxybenzoic and hydroxycinnamic acid derivatives in C. anguria. Due to these metabolic variations, the antioxidant and antibacterial activities were increased with in vitro regenerated plants than in vivo plants. This is the first report describing the production of phenolic compounds and biological activities from in vitro and in vivo regenerated plants of C. anguria.

Crescimento micelial e produção de conídios de Ascochyta cucumis em diferentes meios de cultura e regimes de luz / Mycelial growth and conidial production of Ascochyta cucumis in different culture media and light regimen

A planta da melancia pode ser infectada por diversos patógenos que podem provocar perdas na produtividade e qualidade dos frutos. Entre estes, o fungo Ascochyta cucumis, que é o agente causal do crestamento gomoso do caule em plantas de melancia pode ser considerado um grande problema. Para estudos de laboratório e de campo é importante ter um crescimento e esporulação abundante do patógeno em estudo. No entanto, estudos sobre a esporulacao de A. cucumis em diferentes meios de cultura são escassos na literatura nacional e internacional. O objetivo deste trabalho foi estudar a influência de diferentes meios de cultura e do regime de luz no crescimento micelial e produção de conídios de A. cucumis. Foi utilizado o delineamento inteiramente casualizado, em esquema fatorial 7 x 3, com cinco repetições. Os meios testados foram: BDA; BDA modificado; V8 modificado; aveia; cenoura; folha de melancia e folha de melancia+CaCO3. Todos os meios foram submetidos à luz contínua, fotoperíodo 12 hr e escuro contínuo. Os meios que mais favoreceram o crescimento micelial foram folha de melancia + CaCO3, folha de melancia e BDA modificado, respectivamente, sob regime de luz contínua. Maior produção média de conídios foi obtida nos meios folha de melancia e folha de melancia+CaCO3. O meio folha de melancia+CaCO3 foi o que mais favoreceu a produção de conídios mesmo em diferentes regimes de luz.

Watermelon plants can be infected by different pathogens that can cause losses in yield and fruit quality. Among these, the fungus Ascochyta cucumis, which is the causal agent of gummy stem blight in watermelon plants can be considered the major problem. To laboratory and field studies it is important to have an abundant growth and sporulation of the studied pathogen. However, studies on the sporulation of A. cucumis at different culture media are scarce in the national and international literature. Thus, the objective of this work was to study the effect of different culture media and the light regimens on the mycelial growth and conidial production of A. cucumis. The experiments were performed in a completely randomized design in a factorial 3 x 7, with five replicates. The media tested were the following: BDA, modified BDA, modified V8, oatmeal, carrot, watermelon leaf and watermelon leaf + CaCO3. All media were submitted to continuous light, 12 hr photoperiod and continuous darkness. The media that most favored the mycelial growth were the watermelon leaf + CaCO3, watermelon leaf and modified BDA under continuous light regimen. Increased average production of conidia was afforded by watermelon leaf media and watermelon leaf + CaCO3 media. The watermelon leaf + CaCO3 media was the one that most favored the production of conidia, even at different levels of light regimens.

Using of polyacrylamide as growth media in germination of cucumber seeds and barley grains

This study was conducted on cucumber seeds variety of [[DAMEX, Fl line -105] and barley seeds variety of [Aruge, lineS-R]. Effort was made to compare germination and growth of cucumber and barley seeds under in vitro condition by using of both polyacryiamide [PCA] and Czapek dox ager media. Both media were supplied with growth regulators Gibberellic acid [Gas] at concentrations 4ppm, IGppm and Indol-3-buteric acid [3-IBA] at concentrations 4ppm and 16 ppm respectively. After weeks of growth and germination, seeds were transferred to soil pots for adaption. Important seedling characters like total seedling length, root length and shoot length were recorded also DNA amount estimated. The result shown that, no significant difference was observed in total seedling length between both polyacrylmide and Czapek dox ager media also estimation of DNA amount does not reveal to any significant differences, barley seedling that grown in Czapek dox ager media shown an increase in their shoot lenght compared with barley seedling grown in polyacryiamide media. Root length increased significantly in barley seeds grown in polyacryiamide media only. It can be noticed that, cucumber seedlings grown on polyacriyamide media showed an increase in their shoot length while cucumber seedling that grown on czapek dox ager media showed an increase in their root length. Growth regulators [GAs and 3-IBA] increased root length of both cucumber and barley seedling. Also they increased root length of barley seedling that grown in czapek dox ager media

Application of biofungicides in control of damping disease off in greenhouse crops as a possible substitute to synthetic fungicides

The purpose of this study was to evaluate the effectiveness of a commercial biofungicide such as Trichomix-HV in controlling damping-off disease in cucumber seedlings of greenhouses. In this regard, 504 fungal isolates were collected from greenhouses at 31 districts in city of Jiroft in Iran. Pythium aphanidermatum, P.ultimum, P. irregulare, Phytophthora drechsleri, and Ph. melonis accounted for 9.9%, 8.3%, 4.5%, 4.9%, and 21% of total isolates collected, respectively. Isolates of P. aphanidermatum obtained from commercial cucumber in greenhouses were tested in vitro and under greenhouse conditions for sensitivity to chemical and biological treatments. To this aim, Trichomix-HV a commercial formulation of Trichoderma harzianum strain T969 and the fungicides Metalaxyl and Metalaxyl MZ were amended into the culture medium as well as into sterilized or non-sterilized greenhouse soils inoculated by the pathogen and containing plants at the seedling stage. Trichomix-HV significantly [P < 0.001] reduced seedling infection at a rate of 82% when applied into soil medium at a concentration of 107 conidia ml/L and reduced vegetative growth of Pythium aphanidermatum in vitro. The result from this study shows that Trichomix-HV can be effectively used as a biocontrol agent for controlling damping-off cucumber seedlings and having the potential to replace chemical fungicides as a mean of disease control

Preferência de oviposição e sua relação com o desempenho de Diaphania hyalinata (L, 1758) (Lepidoptera: Crambidae) em cucurbitáceas / Preferência de oviposição e sua relação com o desempenho de Diaphania hyalinata (L, 1758) (Lepidoptera: Crambidae) em cucurbitáceas

Diaphania hyalinata L. (Lepidoptera, Pyralidae) destaca-se como principal praga da família Cucurbitaceae. Este lepidóptero é oligófago de hábito polífago, que desperta largo interesse de estudos da sua ecologia comportamental por motivos de manejo em culturas de grande importância econômica como o meloeiro (Cucumis melo L.). Dada esta situação, trabalhos básicos de entendimento de aspectos da ecologia são necessários para a melhoria das formas de manejo, principalmente no aspecto do monitoramento populacional. Diante disso, a presente pesquisa teve como objetivo verificar se a escolha do hospedeiro exercida por fêmeas de D. hyalinata corresponde ao melhor desempenho da prole e como os hospedeiros influenciam sua dinâmica populacional. Testes de oviposição com chance de escolha foram realizados em melão, melancia, maxixe, bucha, melãode-são-caetano e pepino, para estabelecimento de um ranking de preferência. Para o desempenho das lagartas e reprodução foi escolhido o melão (dentre o mais preferido) e a bucha e o pepino (dentre os hospedeiros menos preferidos). Os resultados suportam a hipótese de que a escolha de hospedeiro é relacionada com o desempenho da prole e que D. hyalinata demonstrou possuir plasticidade ao lidar com diferentes hospedeiros o que pode ser um indicativo de capacidade de adaptação a recursos alimentares que flutuam em termos de qualidade e disponibilidade. No entanto, de modo geral, esta plasticidade tem custos elevados, principalmente em termos reprodutivos.

Diaphania hyalinata L. (Lepidoptera, Pyralidae) stands out as a major pest of the Cucurbitaceae family. This insect is oligophagous with a polyphagous habit, which arouses wide interest in studies of their behavioral ecology for reasons of pest management in crops of high economic importance such as muskmelon (Cucumis melo L.). Given this situation, basic studies aimed at an understanding of ecological aspects of this pest are needed to improve pest management systems, especially in the aspect of population monitoring. Given this, the present study was aimed to determine whether the choice of the host exerted by females of D. hyalinata corresponds to the best performance of the offspring and how the hosts influence their population dynamics. Oviposition-choice tests were performed on melon, watermelon, cucumber, loofah, balsam apple and cucumber, to establish a ranking of preference. For the performance of larvae and reproduction the melon was chosen (among the most preferred hosts) along with loofah and cucumber (among the least preferred hosts). The results support the hypothesis that the choice of host is related to the performance of the offspring and D. hyalinata has demonstrated plasticity in dealing with different hosts which may be indicative of ability to adapt to fluctuating food resources in terms of quality and availability. However, generally this plasticity is expensive, especially in reproductive terms.

Soft Rot on Cucumis melo var. makuwa Caused by Rhizopus oryzae

Rhizopus oryzae is reported for the first time on Cucumis melo L. var. makuwa Makino. A detailed description of this Korean specimen is given, along with its rDNA internal transcribed spacer sequence. On the basis of mycological characteristics and molecular data, the fungus was identified as R. oryzae Went & Prinsen Geerligs.

Comparative study of selected organically and conventionally vegetables

Due to the growing interest in organic products, a comparison between the chemical and biological safety of organic and conventional vegetables was undertaken. Organic and conventional potato, tomato and cucumber were the products purchased from Sekem Company, Cairo, Egypt. Moisture, protein, fat, ash, carbohydrates, phosphorus, vitamin C, heavy metals such [Nickel, cadmium.cobalt and lead], and pesticides residues were determined in all investigated samples. The biological experiment was done on 42 adult male albino rats. Rats were divided into 7 groups. Group [1] fed on basal diet [control group], group [2] fed on basal diet with organic tomato [2.5%], group [3] fed on basal diet with conventional tomato [2.5%], group [4] fed on basal diet with organic cucumber [2.5%], group [5] fed on basal diet with conventional cucumber [2.5%], group [6] fed on basal diet with organic potato [5%], group [7] fed on basal diet with conventional potato [5%]. At the end of the experimental period [4 weeks] rats were scarified and blood samples were collected to separate serum for estimating liver and kidney functions and lipid profile. The results illustrated that, the nutritional value of organic vegetables was higher than the conventional vegetables. The level of pesticides residues in organic vegetables was very low comparing to conventional vegetables. In addition, the heavy metals [cadmium, nickel, and lead] were found in both organic and conventional vegetables but they were higher in conventional vegetables than organic vegetables. The organic tomato significantly increased serum HDL-C. Organic cucumber significantly decreased serum VLDL-C and TG. While all organic and conventional did not affect serum LDL-C. Total cholesterol and kidney functions. Conventional cucumber caused a significant increase in serum uric acid. On the other hand, all tested conventional vegetables significantly increased serum ALT. While organic tomato and cucumber did not affect liver enzymes but, organic potato led to slightly increase in liver enzymes. In conclusion, the present study suggests that regular survey of organic vegetables should be done in order to assure food safety and to protect the end users from food risks that might injure their health

Effects of cucumis metuliferus e mey. Ex naud (cucurbitaceae) fruit extract on some male reproductive parameters in adult rats

The effect of the extract of Cucumis metuliferus fruit on some male reproductive parameters was investigated in albino rats. The LD50 of the extract was above 5000 mg/kg body weight when administered orally. Histological studies showed that there was no remarkable change in the testes histology compare to the control. The effects on sperm cells showed a statistically significant (P0.05) increase in total sperm count with an insignificant (P0.05) increase in viability count in rats treated with 500 mg/kg dose point. On the other hand; 1000 mg/kg dose point produced significant (P0.05) decrease in total sperm count and viability count compare to control. This result suggests that C. metuliferus fruit extracts could be beneficial in increasing sperm/semen integrity

Qualidade de melões ( Cucumis melo L. var. cantalupensis Naud. ), híbrido Torreon, produzidos em hidroponia e armazenados em embalagens de polietileno / Quality of Torreon hybrid melon fruits ( Cucumis melo L. var. cantalupensis Naud. ) grown in hydroponic system and stored in polyethylene packaging

Este experimento teve por objetivos avaliar a permeabilidade de filmes de polietileno de diferentes espessuras e densidades ao O2 e ao CO2, a composição gasosa (O2, CO2 e etileno) formada no interior das embalagens e a qualidade físico-química de melões (Cucumis melo L. var. cantalupensis Naud.), híbrido Torreon, produzidos no sistema hidropônico "Nutrient Film Technique" (NFT) e armazenados em embalagens de polietileno. Os tratamentos avaliados foram: (1) armazenamento refrigerado (sem uso de filme); (2) polietileno de baixa densidade (PEBD) de 40µm; (3) PEBD de 60µm; (4) PEBD de 90µm; (5) polietileno de média densidade (PEMD) de 40µm; (6) PEMD de 60µm. Os frutos permaneceram armazenados durante 25 dias a 3,8±0,2ºC e por mais dois dias a 20ºC. Os filmes de PEBD de 60 e 90µm e o PEMD de 60µm apresentaram menor permeabilidade ao CO2, mantendo as maiores concentrações de CO2 nas embalagens. O filme de PEBD de 90µm apresentou menor permeabilidade ao O2. A menor concentração de etileno foi obtida com o uso de PEBD de 40µm. O uso de filmes reduziu drasticamente a perda de massa dos frutos, quando comparados aos frutos não embalados. Os frutos acondicionados na embalagem de PEBD de 40µm mantiveram uma maior firmeza da polpa após o período de armazenamento, não diferindo estatisticamente dos frutos armazenados em PEMD de 40µm. Já a incidência de podridões foi significativamente menor nos frutos armazenados em PEMD de 60µm. De modo geral, os filmes avaliados mantêm semelhante a qualidade físico-química de melões híbrido Torreon produzidos hidroponicamente no sistema NFT.

Viabilidade da irrigação do meloeiro com águas salinas em diferentes fases fenológicas / Feasibility of irrigation of musk melon with salinity water in different phenological stages

Com o objetivo de estudar os efeitos da aplicação de águas de irrigação de diferentes salinidades no rendimento do melão irrigado por gotejamento e de associar a produção obtida com o custo da água utilizada, desenvolveu-se este trabalho em Mossoró-RN. Aguas de diferentes salinidades (S1=0,6, S2=1,9, S3=3,2 e S4=4,5dS m-1), utilizadas de forma incremental em três estádios de desenvolvimento ou sem variar durante o ciclo da cultura, formaram dez tratamentos arranjados em blocos inteiramente casualizados com quatro repetições. O uso de águas salinas por longos períodos afetou a produção de melão. Substituições tardias na salinidade da água tenderam a não exercer efeito significativo sobre a produção do meloeiro. O tratamento irrigado com a água de menor salinidade durante todo ciclo apresentou, simultaneamente, o maior custo com água de irrigação e o maior lucro na produção de melão.

Estimativa do plastocrono em meloeiro (Cucumis melo L) cultivado em estufa plástica em diferentes épocas do ano / Estimating the plastochron in muskmelon (Cucumis melo L) grown inside plastic greenhouse at different planting dates

O meloeiro (Cucumis melo L.) é uma hortaliça de alto valor econômico. A emissão de nós é um componente importante em modelos matemáticos de simulação do crescimento e desenvolvimento de culturas de hábito de crescimento decumbente como o meloeiro e outras cucurbitáceas. A emissão de nós pode ser calculada utilizando-se o conceito do plastocrono, que é o intervalo de tempo entre o aparecimento de nós sucessivos em uma haste de dicotiledôneas. Quando a soma térmica é usada como medida de tempo fisiológico em plantas, o plastocrono tem como unidades °C dia nó-1. Estudos anteriores mostraram que o plastocrono em meloeiro varia com o genótipo e a época de cultivo. Este trabalho teve por objetivo estimar o plastocrono em meloeiro transplantado em diferentes épocas de cultivo no interior de estufa plástica. Foram realizadas 12 épocas de semeadura e transplante no interior de uma estufa plástica de 10m X 25m, coberta com polietileno transparente de baixa densidade, localizada no Campo Experimental do Departamento de Fitotecnia da Universidade Federal de Santa Maria, RS. O híbrido utilizado foi o HY-MARK (grupo Cantaloupe). Em 12 plantas etiquetadas por época de transplante, contou-se o número de nós visíveis (NN) na haste principal da planta duas vezes por semana. A soma térmica diária (STd, °C dia) foi calculada levando-se em conta as temperaturas cardinais de aparecimento de nós em meloeiro (10, 34 e 45°C). A soma térmica acumulada (STa, °C dia), a partir da data de transplante das plântulas, foi calculada somando-se a STd. O plastocrono foi calculado como sendo o inverso do coeficiente angular da regressão linear entre NN e STa para cada época. O plastocrono calculado variou entre as épocas de cultivo de 13,4 a 21,8°C dia nó-1, com um valor médio de 18,6 (±2,3)°C dia nó-1. Esta diferença de plastocrono entre as épocas de cultivo pode representar vários dias do calendário civil se o interesse é predizer eventos associados ao NN na planta de meloeiro, como por exemplo a data de abertura da primeria flor masculina e da primeria flor hermafrodita.