Navegando por Assunto "Alface"

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Avaliação da germinação e crescimento inicial de plântulas de Lactuca sativa L. expostas à polivinilpirrolidona
(2022-05-27) Sales, Érica Danúbia Souza; Nunes, Ramom Rachide; http://lattes.cnpq.br/6182302726895126; http://lattes.cnpq.br/3843458808851603
Seed germination is a crucial moment for plant development and growth, once the species has suffered any kind of injury, excess or scarcity, the consequences can be permanent. Thus, the present work aims to evaluate the germination of Lactuca sativa L. (lettuce) in different concentration of polyvinylpyrrolidone polymer (PVP). Seed sowing (30/plate) was conducted in sterilized Petri dishes containing filter paper. In each plate, 3mL of the aqueous PVP solution was added at concentrations 0.001 mmol/L, 0.01 mmol/L, 0.1 mmol/L, 1 mmol/L and a control group with distilled water. Each treatment had 3 replicates. Seed germination was evaluated daily, at the end of the 7th day, measurements of hypocotyl length, radicle, fresh and dry mass weight, germination percentage tests, vigor index, tolerance, germination speed, water content and photosynthesizing pigments were performed.. The data were expressed in mean ± standard error and submitted to one way ANOVA followed by the Tukey test (the means were considered different when p<0.05). The group treated with 1 mmol/L presented the radicle development affected, while all others did not present major impacts. %G, IVG, IT, hypocotyl and photosynthetic pigments did not present significant results when compared to the control group. Our data indicates a warning sign for the polyvinylpyrrolidone disposal, and highlights the need of further research regarding its toxicity.
Avaliação da germinação e do crescimento inicial de plântulas de Lactuca sativa L. expostas ao cloreto de alumínio em microambiente
(2019) Pádua, Lisandra Celeste da Silva; Saraiva, Rogério de Aquino; http://lattes.cnpq.br/6812072552819682; http://lattes.cnpq.br/1077354209259707
Aluminum when in low soil concentrations can promote growth or even other benefits to plants. However, in acidic soils (pH <5) this metal can cause phytotoxic effects on plants, becoming one of the limiting factors for their growth. The present study aimed to evaluate the phytotoxicity of aluminum chloride (AlCl3) on the germination and initial development of Lactuca sativa L. For this purpose, aqueous solutions of AlCl3 were prepared at concentrations of 0 mg.L-1, 5 mg.L-1,10 mg.L-1, 50 mg.L-1 and 100 mg.L-1. Followed by the application of 3 mL of each solution in Petri dishes containing 25 lettuce seeds each, germinated in a B.O.D (Biochemical Oxigen Demand) chamber lasting seven days. The parameters used to evaluate Al phytotoxicity were: root length, hypocotyl and total, root diameter, NSG / day, IVG, vigor, IT chlorophyll and carotenoid contents and physicochemical parameters. Considering the phytotoxic effects of aluminum demonstrated by the reduction in root size, hypocotyl, total length and increase of root diameter of the seedlings that received the aluminum treatments, the seedlings that received the treatment with the highest concentration showed to be less tolerant to aluminum, however germination, IVG, vigor and chlorophyll and carotenoid contents were not negatively affected by aluminum. Thus it can be concluded that aluminum, despite causing root damage, was not sufficient to inhibit the initial development of lettuce seedlings.
Avaliação da produção de mudas de alface sob diferentes tipos de bandeja
(2018) Silva, Gabriel Sousa Vicente da; Carvalho Filho, José Luiz Sandes de; http://lattes.cnpq.br/5884704145845869; http://lattes.cnpq.br/7223904539125792
Avaliação do efeito do peróxido de hidrogênio exógeno na germinação e crescimento inicial de Lactuca sativa L.
(2021-02-26) Silva, Maria da Saúde da; Saraiva, Rogério de Aquino; http://lattes.cnpq.br/6812072552819682; http://lattes.cnpq.br/4745938613418902
Hydrogen peroxide is a reactive species of oxygen produced in cellular metabolism when the cell is subjected to stress situation, in its exogenous form this substance has been widely used for various activities, including bleaching techniques in the textile industry, treatment of industrial effluents and domestic activities. With this, exogenous H2O2 at low concentrations is able to positively influence plant growth, and in the literature little is known how this substance at high concentrations can affect the development of species and how much of it is necessary for 50% inhibition of root growth to occur. With this, the present study aimed to evaluate possible safe concentrations of H2O2 during the initial development of Lactuca sativa L. For the assembly of the experiment, 25 seeds and 3 mL of the aqueous solution of H2O2 were added at the concentrations of (1.065 mM), 0.25% (v/v) ; (2,131 mM), 0.5% (v/v); (4.262 mM), 1%, (v/v) and (5.327 Mm), 1.25% (v/v), and a control group containing only distilled water. Each treatment consisted of 4 repetitions. Seed germination was evaluated for 7 days and subsequently measurements of the length of the hypocotyl and radicle of the seedlings were made, and analysis of photosynthetic pigment levels of the control group and concentration of 1.25% v/v (5.327 mM). The group treated with 0.25% v/v (1.065 mM) did not present the development of the radicle affected by the substance, while all other treatments affected the initial development of seedlings, both in the radicle and hypocotyl, since the concentration of 1.980 mM has already decreased and the root growth of plants has already occurred. . There was a significant decrease in chlorophyll a and b levels, as well as carotenoides at the concentration of 5.327 Mm, 1.25% (v/v) compared to the control group. This information helps control the appropriate concentrations of H2O2 released into the environment, so as not to cause imbalances in ecosystems.
Avaliação do potencial alelopático de Chloroleucon foliosum (Benth) G. P. Lewis sobre a germinação e crescimento inicial de alface
(2019) Silva, Sara de Souza; Saraiva, Rogério de Aquino; http://lattes.cnpq.br/6812072552819682; http://lattes.cnpq.br/0125367619888442
Chloroleucon foliolosum(Benth.) G. P. Lewis is a native tree from Caatinga commonly known as "arapiraca" and important to the timber industry and in folk medicine. However, there are few studies aimed at the possible impactscaused by the plant residues when those are released into the environment. Thus, this work aimed to evaluate the allelopathic effect of C. foliolosumleaf and stem ethanolic extracts (EFCF and ECCF, respectively) on germination and initial growthof lettuce (Lactuca sativaL.) seedlings. After collectionof the plant material, the ethanolic extracts were prepared from 50% ethanol. The qualitative phytochemical characterization of EFCF and ECCF was performed according to the methodology of Matos (1997). Thegermination assay was performed in microenvironments consisting of previously sterilized Petri dishes containing filter paper as substrate, containing lettuce seeds. The extracts were tested in concentrations of 1 mg/L, 10 mg/L, 100 mg/L, 1000 mg/L and 10,000 mg/L, as well asthecontrolgroup (distilled water), performed inquadruplicate. After 7 days of germination, was performedthe radicles and aerial parts morphometry, and the calculation of the rate of germination (IVG). The means were submitted to one-way ANOVA followed by the Tukey test and the differences between the treatments were considered significant for the P value <0.05. For both extracts, concentrations equal to or greater than 100 mg/L of EFCF were able to negatively affect lettuce growth,according to the length of radicle and shoot and IVG when compared to control. In phytochemical prospecting, both extracts have alkaloids and tannins; saponins, anthraquinone and catechins in ECCF, and flavonoids and phenolic compounds in EFCF. Therefore,the compounds contained in the extracts can generate different responses, so that the literature indicates that certain alkaloids and some phenolic compounds may be cytotoxic, having their effect enhanced by the presence of saponins and tannins, which mayassociate with the cell wall and facilitate the entryof allelochemicals. Considering the importance of the development of new technologies for the use of Caatinga plants, the study withextracts of C. foliolosumshow high toxicity in the concentrations tested (except 1 mg/L of ECCF), so that the,increase in theconcentrationpotentializedthe effect.
Avaliação e seleção de progênies F2:4 de alface com resistência ao nematoide-das-galhas e à podridão-mole
(2024) Lima, Rayhonay Souza Rodrigues de; Pereira, Jacqueline Wanessa de Lima; http://lattes.cnpq.br/1563969275190315; http://lattes.cnpq.br/3453832325160775
Efeito de diferentes doses de nitrogênio no pendoamento de cultivares de alface
(2017) Maranhão, Wesley Albuquerque; Carvalho Filho, José Luiz Sandes de; http://lattes.cnpq.br/5884704145845869; http://lattes.cnpq.br/6939497860921425
Favaliação da atividade alelopática do extrato aquoso de Senna siamea (Lam.) H.S. Irwin & Barneby sobre o desenvolvimento de plântulas de Lactuca sativa l.
(2019) Medeiros, Luanna Torres de; Saraiva, Rogério de Aquino; http://lattes.cnpq.br/6812072552819682; http://lattes.cnpq.br/8680775638977616
Allelopathy is understood as a process that occurs in plant communities, where species act through mechanisms capable of interfering with the growth and development of other plants, through the release of chemicals, also called allelochemicals, which are derived from processes that cause they occur naturally in their secondary metabolism and subsequently deposited on the substrate. These allelochemicals may perform harmful or advantageous actions when in contact with other plants present in the same environment, depending on the amount and circumstances in which they are in place. Senna siamea (Lam) H.S. Irwin & Barneby, popularly known as canafistula or cassia-siam is originally from Thailand, but widely found in the Brazilian semiarid region, which has abundant application in landscape use, shading and various ethnopharmacological research. Considering the large dispersal of S. siamea species throughout the Brazilian Northeast, we aimed to evaluate its allelopathic activity on the development of Lactuca sativa (lettuce) seedlings. For this, 25 L. sativa seeds were placed in Petri dishes, and at the same time different concentrations (0, 25, 50, 75 and 100) of the aqueous extract of Senna siamea leaves were added, followed by The seeded plates wererelocated to a germination chamber where they remained for seven days under daily monitoring. The analyzes were performed through measurements of seedling root and hypocotyls and phytotoxicity bioassays and phytochemical tests, from which the presence of secondary metabolites classes such as flavonoids and phenolic compounds were detected. From this, an inhibitory effect was observed in relation to lettuce seedlings, which was observed by observing the root and hypocotyl length, decrease of vigor, presence of necrosis and reduction of chlorophyll and carotenoid content. Based on the knowledge obtained, it is possible to evidence that this plant species has relevant potential as a source of chemical compounds with significant biotechnological properties in the production of natural herbicides for less aggressive use against the weeds, besides the search for more information for proper use of plant species that have allelopathic potential.
Influência do armazenamento no vigor das sementes de alface crespa
(2022) Santos, Mirelly Gonzaga dos; Carvalho, Rejane Rodrigues da Costa e; http://lattes.cnpq.br/3307316028992311; http://lattes.cnpq.br/3394557194566234
O papel dos compostos auxino-similares extraídos de hidrocarvões de resíduos de milho na germinação de sementes-teste de Lactuca sativa
(2022-12-14) Lima, Edson Thiago Gomes de; Nunes, Ramom Rachide; http://lattes.cnpq.br/6182302726895126; http://lattes.cnpq.br/1474841030315836
Neste trabalho estudou-se a atividade auxino-similar de hidrocarvões líquidos e sólidos obtido a partir de resíduos de milho, preparados por carbonização hidrotérmica (HTC). Os bioensaios foram realizados testando concentrações do hidrocarvão líquido na faixa de 0,0557-5570,0 mg de carbono L-1 ; e hidrocarvão sólido na faixa de 0,026-2600,0 mg de carbono L-1 . A matéria orgânica dissolvida (DOM) foi extraída para realização de testes utilizando hidrocarvão sólido. Os bioensaios foram realizados com sementes de Lactuca sativa. Os métodos instrumentais MEV, ATR-FTIR e Py-GC/MS foram usados para avaliar o efeito da HTC na produção/composição de hidrocarvão. O hidrocarvão líquido apresentou intensa bioatividade, inibindo completamente a germinação das sementes-teste em concentrações acima de 696 mg C L-1 . O hidrocarvão líquido foi consideravelmente mais bioativo que a DOM, mesmo apresentando efeito auxino-similar nos testes de germinação. A análise MEV mostrou como a HTC transformou a superfície da matériaprima, abrindo poros e sulcos nos hidrocarvões. O ATR-FTIR também mostrou que a HTC mudou a composição química dos resíduos de milho, reduzindo os grupos hidroxila e enriquecendo o material com grupos funcionais aromáticos. O Py-GC/MS permitiu a identificação das moléculas envolvidas nos efeitos do tipo AIA: ácidos carboxílicos (lineares e aromáticos) e aminoácidos. A concentração de mais moléculas bioativas, ao invés de sua simples presença na fração do hidrocarvão, determinou o efeito bioestimulante, além de uma boa regressão linear entre a atividade auxino-similar e a concentração de moléculas ativas estimulantes.
Relatório de Estágio Supervisionado Obrigatório
(2019) Rodrigues, Élidy Dayane Barbosa; Carvalho Filho, José Luiz Sandes de; http://lattes.cnpq.br/5884704145845869; http://lattes.cnpq.br/6071102655829750
Vivência Interdisciplinar na Embrapa Hortaliças (CNPH) com foco em ações de pesquisa no melhoramento genético de alface e tomate
(2023-09-15) Santos Neto, Jaime Corbiniano dos; Carvalho, José Luiz Sandes de; Boiteux, Leonardo Silva; http://lattes.cnpq.br/3592032092912418; http://lattes.cnpq.br/5884704145845869; http://lattes.cnpq.br/3331839710139216