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1.
Braz. j. biol ; 84: e257314, 2024. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1355908

ABSTRACT

Abstract Melon production in the Brazilian semi-arid region is subject to the use of marginal waters with high salinity. However, the use of regulators and bioactivators in seed treatment can mitigate the harmful effects of salts in irrigation water. In this context, the objective was to evaluate the effect of pre-germination treatments with plant regulators and bioactivator in melon seeds for the production of seedlings irrigated with biosaline water from fish farming effluent. For this, two trials with the Goldex and Grand Prix hybrids were carried out separately. A completely randomized design was used in a 4 × 3 factorial scheme (pre-germination treatments × water dilutions). In addition to the control, the seeds were treated with salicylic and gibberellic acids and thiamethoxam. The waters used for irrigation were local-supply water, fish farming effluent (biosaline water) and these diluted to 50%. Physiological and biochemical analyses were performed for fourteen days. Biosaline water (5.0 dS m-1) did not affect the emergence of Goldex melon seedlings, but compromised the establishment of the Grand Prix cultivar. Seed pre-treatments with salicylic and gibberellic acids attenuate the effects of water salinity and promote growth modulations, resulting in more vigorous melon seedlings.


Resumo A produção de meloeiro no semiárido brasileiro está sujeita a utilização de águas marginais com salinidade elevada. Entretanto, a utilização de reguladores e bioativadores no tratamento de sementes podem mitigar os efeitos nocivos dos sais na água de irrigação. Nesse sentido, objetivou-se avaliar o efeito de tratamentos pré-germinativos com fitorreguladores e bioativador em sementes de melão para a produção de mudas irrigadas com água biossalina de efluente de piscicultura. Para isso, dois ensaios com os híbridos Goldex e Grand Prix foram realizados separadamente. Utilizou-se delineamento inteiramente casualizado em esquema fatorial 4 × 3 (tratamentos pré-germinativos × diluições de água). Além do controle, as sementes foram tratadas com os ácidos salicílico e giberélico, e tiametoxam. As águas utilizadas para irrigação foram a de abastecimento local, efluente de piscicultura (água biossalina) e estas diluídas a 50%. Durante quatorze dias foram realizadas as análises fisiológicas e bioquímicas. A água biossalina (5,0 dS m-1) não afetou a emergência de plântulas de meloeiro Goldex, mas prejudicou o estabelecimento da cultivar Grand Prix. Os pré-tratamentos de sementes com os ácidos salicílico e giberélico atenuam os efeitos da salinidade da água e promovem modulações no crescimento, proporcionando mudas de meloeiro mais vigorosas.


Subject(s)
Germination , Cucurbitaceae , Seeds , Water , Seedlings
2.
Rev. biol. trop ; 71(1)dic. 2023.
Article in English | SaludCR, LILACS | ID: biblio-1514963

ABSTRACT

Introduction: The lack of knowledge on seed germination and seedling establishment is a main constraint for the restoration of degraded areas, including the tropical dry forest known as Caatinga. Objective: To assess reserve and secondary metabolite mobilization during seed germination and seedling establishment in Erythina velutina. Methods: We scarified, disinfected, imbibed, sown between towel paper, and incubated seeds under controlled conditions. We hydroponically cultivated seedlings in a greenhouse. We harvested cotyledons at seed imbibition, radicle protrusion, hypocotyl emergence, apical hook formation and expansion of cordiform leaves, first trifoliate leaf, and second trifoliate leaf. Results: Seeds contained approximately 20 % starch, 14.5 % storage proteins, 11.6 % neutral lipids, and 5.7 % non-reducing sugars on a dry weight basis. Soluble sugars were mainly consumed from hypocotyl emergence to apical hook formation, while major reserves were mobilized from apical hook formation to expansion of first trifoliate leaf. Enzymatic activity increased from mid to late seedling establishment, causing the mobilization of starch, oils, and proteins. Terpenoid-derivatives, flavonoids, phenolic acids, and alkaloids were detected. Flavonoids and phenolic acids were present at almost all stages and terpenoid-derivatives disappeared at expansion of cordiform leaves. Conclusion: Soluble sugars support early seedling growth, while starch, oils and proteins are simultaneously mobilized from mid to late establishment by amylases, lipases, and acid proteases. The cotyledons contain secondary metabolites, which may act in seedling defense. High content of reserves and presence of secondary metabolites in the cotyledons could enable E. velutina seedlings endure stress, validating their use in the restoration of degraded areas.


Introducción: La falta de conocimiento sobre la germinación de semillas y el establecimiento de plántulas es una de las principales limitaciones para la restauración de áreas degradadas, incluido el bosque seco tropical conocido como Caatinga. Objetivo: Evaluar la movilización de reservas y metabolitos secundarios durante estas etapas de desarrollo en Erythina velutina. Métodos: Las semillas fueron escarificadas, desinfectadas, embebidas, sembradas entre toallas de papel e incubadas bajo condiciones controladas. Cultivamos las plántulas hidropónicamente en un invernadero. Recolectamos los cotiledones en la imbibición de la semilla, la protrusión de la radícula, la emergencia del hipocótilo, la formación del gancho apical y la expansión de las hojas cordiformes, la primera y segunda hoja trifoliada. Resultados: Las semillas contenían 20 % de almidón, 14.5 % de proteínas de almacenamiento, 11.6 % de lípidos neutros y 5.7 % de azúcares no reductores en peso seco. Los azúcares solubles se consumieron desde la emergencia del hipocótilo hasta la formación del gancho apical. Las principales reservas se movilizaron desde la formación del gancho apical hasta la expansión de la primera hoja trifoliada. La actividad enzimática aumentó desde la mitad hasta el final del establecimiento de las plántulas, movilizando almidón, aceites y proteínas. Se detectaron derivados de terpenoides, flavonoides, ácidos fenólicos y alcaloides. Los flavonoides y los ácidos fenólicos estuvieron en casi todas las etapas y los derivados terpenoides desaparecieron en la expansión de las hojas cordiformes. Conclusión: Los azúcares solubles apoyan el crecimiento temprano de las plántulas; el almidón, los aceites y las proteínas se movilizan simultáneamente desde el establecimiento medio hasta el final por amilasas, lipasas y proteasas ácidas. Los cotiledones contienen metabolitos secundarios, que pueden actuar en la defensa de las plántulas. El alto contenido de reservas y los metabolitos secundarios en los cotiledones podría permitir que las plántulas de E. velutina toleren estrés, validando su uso en la restauración de áreas degradadas.


Subject(s)
Germination , Erythrina , Environmental Restoration and Remediation/methods , Fabaceae , Brazil
3.
Rev. biol. trop ; 71(1)dic. 2023.
Article in English | LILACS, SaludCR | ID: biblio-1514961

ABSTRACT

Introduction: Cattleya crispa is an ornamental epiphytic orchid with geographic distribution restricted to the Brazilian Atlantic Forest. Due to predatory extractivism and human-induced habitat loss, this species appears on the Red List of Brazilian Flora. Objective: To characterize morpho-anatomical aspects regarding germination and post-seminal development from C. crispa seeds; as well as studying the effect of cryopreservation on these seeds. Methods: We used light microscopy and electron microscopy to describe the microstructure of a 100 ripe seeds. We evaluated seed viability, seed germination, survival rate and protocorm weight in cryopreserved and non-cryopreserved material, with four replicas per treatment using 20 mg of plant material. Results: The seeds are fusiform, whitish yellow with a length from 700 to 900 µm and a water content of 5 %. Germination began seven days after sowing, the formation of the globular protocorm at 30 days and the formation of the seedling occurred 150 days. The persistent seed coat can compress the protocorm and cause it to collapse. The cryopreserved seeds presented 87.15 % viability, 78.32 % germination, 8.48 % survival and protocorms with 104.27 mg five months after sowing. Data wasn't different to non-cryopreserved seeds. Conclusions: The cryocapability of the seeds shows that cryopreservation can be used for long-term conservation. The results of this work contribute to the overall biology of C. crispa and to the propagation and storage of genetic material for conservation purposes.


Introducción: Cattleya crispa es una orquídea epífita ornamental con distribución geográfica restringida a la Mata Atlántica brasileña. Debido al extractivismo depredador y a la pérdida de hábitat inducida por el hombre, esta especie aparece en la Lista Roja de la Flora Brasileña. Objetivo: Caracterizar aspectos morfoanatómicos de la germinación y desarrollo inicial de semillas de C. crispa; así como estudiar el efecto de la criopreservación de estas semillas. Métodos: Utilizamos microscopía óptica, microscopía electrónica de barrido y microscopía electrónica de transmisión para describir la microestructura en 100 semillas maduras. Evaluamos la viabilidad de la semilla, la germinación de la semilla, la tasa de supervivencia y el peso de los protocormos en el material criopreservado y no criopreservado, con cuatro réplicas por tratamiento de 20 mg de material vegetal. Resultados: Las semillas son fusiformes, amarillo blanquecinas, con una longitud de 700 a 900 µm y un contenido de agua del 5 %. La germinación comenzó siete días después de la siembra, la formación del protocormo globular a los 30 días y la formación de la plántula a los 150 días. La cubierta de semilla persistente puede comprimir el protocormo y provocar su colapso. Las semillas criopreservadas presentaron 87.15 % de viabilidad, 78.32 % de germinación, 8.48 % de supervivencia y protocormos con 104.27 mg a los cinco meses de la siembra. Los datos no fueron diferentes a las semillas no criopreservadas. Conclusiones: La capacidad criogénica de las semillas muestra que la crioconservación puede utilizarse para la conservación a largo plazo. Los resultados de este trabajo contribuyen a la biología general de C. crispa y a la propagación y almacenamiento de material genético con fines de conservación.


Subject(s)
Germination , Orchidaceae/anatomy & histology , Orchidaceae/embryology , Brazil
4.
Braz. j. biol ; 83: 1-13, 2023. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1468809

ABSTRACT

Interactions between endophytic fungi (EFs) and their host plants range from positive to neutral to negative. The results of such interactions can vary depending on the organ of the infected host plant. EFs isolated from the leaves of some species of plants have potential for use as agents to inhibit seed germination and control invasive plants. The objectives of this study were to identify EFs present in the leaves of Copaifera oblongifolia and to evaluate the role of these fungi in seed germination and seedling development. A total of 11 species of EFs were isolated, which were identified using the internal transcribed spacers (ITS) sequence of the nuclear ribosomal DNA. The isolated species of EFs are generalists and probably are transmitted horizontally. Laboratory tests revealed that filtrates of these fungal isolates differently affect seed germination and seedling development of C. oblongifolia. The species Curvularia intermedia, Neofusicoccum parvum, Pseudofusicoccum stromaticum and Phomopsis sp. negatively affected seed germination, with N. parvum standing out for its negative effects, inhibiting seedling germination and survival in 89 and 222%, respectively. In addition, Cochliobolus intermedius negatively affected seedling development. Thus, the combined use of N. parvum and C. intermedius, or products from the metabolism of these microorganisms, in the control of invasive plants deserves attention from future studies.


As interações entre fungos endofíticos (FEs) e suas plantas hospedeiras variam de positivas, neutras a negativas. Os resultados destas interações podem variar dependendo do órgão da planta hospedeira infectada. FEs isolados de folhas de algumas espécies de plantas têm potencial para serem usados como agentes inibidores da germinação de sementes e no controle de plantas invasoras. Os objetivos deste estudo foram identificar os FEs presentes nas folhas de Copaifera oblongifolia e avaliar o papel destes fungos na germinação das sementes e no desenvolvimento das plântulas. Um total de 11 espécies de FEs foi isolado das folhas de C. oblongifolia e identificado através da sequência dos espaçadores internos transcritos do DNA ribossomal nuclear. As espécies de FEs isoladas são generalistas e provavelmente devem ser transmitidas horizontalmente. Os resultados dos testes de germinação mostraram que filtrados destes isolados fúngicos podem afetar diferentemente a germinação das sementes e o desenvolvimento das plântulas de C. oblongifolia. As espécies Curvularia intermedia, Neofusicoccum parvum, Pseudofusicoccum stromaticum e Phomopsis sp. afetaram negativamente a germinação das sementes de C. oblongifolia. Dentre estas espécies devemos destacar que N. parvum reduziu a germinação e a sobrevivência das plântulas em 89 e 222%, respectivamente. Além disso, Cochiliobolus intermedius afetou negativamente o desenvolvimento das plântulas. Assim, o uso combinado de N. parvum e C. intermedius, ou de produtos do metabolismo destas espécies de fungos, têm potencial para serem usados no manejo de plantas invasoras.


Subject(s)
Animals , DNA, Ribosomal/analysis , Fabaceae/growth & development , Fungi/pathogenicity , Germination , Host Microbial Interactions , Seedlings/growth & development
5.
Braz. j. biol ; 83: e242070, 2023. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1278554

ABSTRACT

Abstract Interactions between endophytic fungi (EFs) and their host plants range from positive to neutral to negative. The results of such interactions can vary depending on the organ of the infected host plant. EFs isolated from the leaves of some species of plants have potential for use as agents to inhibit seed germination and control invasive plants. The objectives of this study were to identify EFs present in the leaves of Copaifera oblongifolia and to evaluate the role of these fungi in seed germination and seedling development. A total of 11 species of EFs were isolated, which were identified using the internal transcribed spacers (ITS) sequence of the nuclear ribosomal DNA. The isolated species of EFs are generalists and probably are transmitted horizontally. Laboratory tests revealed that filtrates of these fungal isolates differently affect seed germination and seedling development of C. oblongifolia. The species Curvularia intermedia, Neofusicoccum parvum, Pseudofusicoccum stromaticum and Phomopsis sp. negatively affected seed germination, with N. parvum standing out for its negative effects, inhibiting seedling germination and survival in 89 and 222%, respectively. In addition, Cochliobolus intermedius negatively affected seedling development. Thus, the combined use of N. parvum and C. intermedius, or products from the metabolism of these microorganisms, in the control of invasive plants deserves attention from future studies.


Resumo As interações entre fungos endofíticos (FEs) e suas plantas hospedeiras variam de positivas, neutras a negativas. Os resultados destas interações podem variar dependendo do órgão da planta hospedeira infectada. FEs isolados de folhas de algumas espécies de plantas têm potencial para serem usados como agentes inibidores da germinação de sementes e no controle de plantas invasoras. Os objetivos deste estudo foram identificar os FEs presentes nas folhas de Copaifera oblongifolia e avaliar o papel destes fungos na germinação das sementes e no desenvolvimento das plântulas. Um total de 11 espécies de FEs foi isolado das folhas de C. oblongifolia e identificado através da sequência dos espaçadores internos transcritos do DNA ribossomal nuclear. As espécies de FEs isoladas são generalistas e provavelmente devem ser transmitidas horizontalmente. Os resultados dos testes de germinação mostraram que filtrados destes isolados fúngicos podem afetar diferentemente a germinação das sementes e o desenvolvimento das plântulas de C. oblongifolia. As espécies Curvularia intermedia, Neofusicoccum parvum, Pseudofusicoccum stromaticum e Phomopsis sp. afetaram negativamente a germinação das sementes de C. oblongifolia. Dentre estas espécies devemos destacar que N. parvum reduziu a germinação e a sobrevivência das plântulas em 89 e 222%, respectivamente. Além disso, Cochiliobolus intermedius afetou negativamente o desenvolvimento das plântulas. Assim, o uso combinado de N. parvum e C. intermedius, ou de produtos do metabolismo destas espécies de fungos, têm potencial para serem usados no manejo de plantas invasoras.


Subject(s)
Germination , Fabaceae , Ascomycota , Seeds , Plant Leaves , Seedlings , Fungi , Curvularia
6.
Braz. j. biol ; 83: e245206, 2023. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1339387

ABSTRACT

Abstract A huge amount of rice cultivation and consumption occur in Asia particularly in Pakistan and China. However, multiple abiotic stresses especially high and low-temperature proved to be a substantial threat for rice production ultimately risks for food security. To overcome various types of abiotic stress; seed priming is among the effective approaches to improve the rice seed germination and growth vigor. Therefore, the present study was planned to evaluate physiological and biochemical modifications in Chinese and Pakistani rice varieties by Qiangdi 863 biological assistant growth apparatus nano treated water (NTW), Osmopriming Calcium chloride (CaCl2), redox priming hydrogen peroxide (H2O2) and hormonal priming by Salicylic acid (SA) under temperature stress conditions. The experiment was performed with completely randomize design conditions. Five rice varieties, nomenclature as Zhongzoa 39, (Chinese rice variety) KSK 133, KS 282, Super basmati and PK 1121 aromatic (Pakistani rice variety) were sown under low temperature (LT) (17ºC), optimal temperature (OT) 27ºC and high temperature (HT) 37ºC conditions. The present study indicated that nanopriming were the most effective treatments increased Germination Energy Percentage (GEP) (96.1, 100, 100%), Speed of Germination (SG) (27.2, 35.45, 37.1), Final Germination Percentage (FGP) (98.2, 99.1, 99.4%), Seedling Dry Weight Biomass (DWB) (0.1, 0.137, 0.14g), Total Chlorophyll Content (0.502, 13.74, 15.21), antioxidant enzymes Superoxide Dismutase (SOD)(3145, 2559, 3345 µg-1FWh-1), Catalase (CAT) (300, 366, 3243 µg-1FWh-1) and decreased Malondialdehyde (MDA) (6.5, 12.2, 6.5 µmol g-1 FW) for Zhongzao 39 and KSK 133 rice varieties under low (LT+NTW), optimal temperature (OP+NTW) and high temperature (HT+NTW) stress., Therefore, nano-priming is recommended to cope with the high and low-temperature stress conditions along with improved productivity of rice.


Resumo Cultivo e consumo de arroz ocorrem em grandes quantidades na Ásia, particularmente no Paquistão e na China. No entanto, vários estresses abióticos, especialmente de alta e baixa temperatura, provaram ser uma ameaça considerável para a produção de arroz, em última análise, riscos para a segurança alimentar. Para superar vários tipos de estresse abiótico, o priming de sementes está entre as abordagens eficazes que melhoram a germinação e o vigor de crescimento das sementes de arroz. Portanto, o presente estudo foi planejado para avaliar as modificações fisiológicas e bioquímicas em variedades de arroz chinês e paquistanês por Qiangdi 863, aparelho assistente biológico de crescimento com água nanotratada (NTW), Osmopriming cloreto de cálcio (CaCl2), peróxido de hidrogênio redox (H2O2) e priming hormonal por ácido salicílico (SA) em condições de estresse de temperatura. O experimento foi realizado em condições de delineamento inteiramente ao acaso. Cinco variedades de arroz, nomenclaturas como Zhongzoa 39 (variedade de arroz chinês), KSK 133, KS 282, Super basmati e PK 1121 aromático (variedade de arroz do Paquistão) foram semeadas sob baixa temperatura (LT) (17 ºC), temperatura ótima (OT) 27 ºC e condições de alta temperatura (HT) 37 ºC. O presente estudo indicou que nanocondicionamento foi o tratamento mais eficaz: aumento da porcentagem de energia de germinação (GEP) (96,1%, 100%, 100%), velocidade de germinação (SG) (27,2, 35,45, 37,1), porcentagem de germinação final (FGP) (98,2%, 99,1%, 99,4%), biomassa de peso seco de mudas (DWB) (0,1 g, 0,137 g, 0,14 g), conteúdo total de clorofila (0,502, 13,74, 15,21), enzimas antioxidantes superóxido dismutase (SOD) (3145, 2559, 3345 µg-1FWh- 1), catalase (CAT) (300, 366, 3243 µg-1FWh-1) e malondialdeído diminuído (MDA) (6,5, 12,2, 6,5 µmol g-1 FW) para as variedades de arroz Zhongzao 39 e KSK 133 sob baixo (LT + NTW), temperatura ótima (OP + NTW) e estresse de alta temperatura (HT + NTW). Portanto, o nanopriming é recomendado para lidar com as condições de estresse de alta e baixa temperatura, juntamente com a produtividade aprimorada do arroz.


Subject(s)
Oryza , Seeds , Stress, Physiological , Temperature , Germination , Seedlings , Hydrogen Peroxide
7.
Int. j. high dilution res ; 21(1): 7-7, May 6, 2022.
Article in English | LILACS, HomeoIndex | ID: biblio-1396590

ABSTRACT

Homeopathy is a technique approved by the MAPA for organic production systems. Experiments demonstrating the effectiveness of homeopathy in agriculture are essential. Aims: To evaluate the effects of homeopathic treatment on soybean seed germination. Methodology: The experiment was performed in MS-Brazil. An area of 70 m² was used, divided into two comparison plots of 30 m² each. The soil of plot 1 (treated group) was treated with 5.25 kg of powdered Lithothamniummixed with 250 ml of 30% hydroalcoholic solution (HS) containing homeopathic ingredients. The soil of plot 2 (control group) was treated with thesame preparationbutwithout homeopathic ingredients. Additionally, the 400 seeds assigned toplot 1 were treated with 0,3 ml of a solution made up of 10 ml of 30% HS with homeopathic ingredients dilutedin 300 ml of water. The 400 seeds assigned toplot 2 were treated with 0.3 ml of a solutionmade up of 10 ml of HS without homeopathic ingredients diluted in 300 ml of water. The homeopathic ingredients Sulph 9C, Mag-c12C, and Calc-p 9C were used on soil and seed treatment. The selection and prescription of those ingredients followed Materia Medica instructions. The experiment was conducted using randomized design and 400 seeds per group were sown. Results and discussion: In plot 1, anaverage of 11 seeds per m² germinated, adding up to 330 germinated seeds at a percentage of 82.5%. In plot 2, an average of 7 seeds per m² germinated, adding up to 210 germinated seeds at a percentage of 52.5%. The frequency of seed germinationin both groups was assessed by the Chi-square test to check for significant differences(p<0.05). There was a statistical difference (p<0.05) in the seed germination in the treated group (n=330) compared to the control group (n=210). Conclusion:Homeopathic compounds can be used as a viable treatment for soybean germination.


Subject(s)
Quantum Theory , Glycine max , Germination , Sustainable Agriculture , Homeopathy
8.
Acta sci., Biol. sci ; 44: e58431, mar. 2022. ilus, tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1391277

ABSTRACT

Hesperozygis ringens (Lamiaceae), popularly known as espanta-pulga, is a threatened species endemic to rocky and sandy regions of the Pampa biome. One factor that can influence the low number of individuals of a species is a low seed germination rate influenced by temperature and/or light. Thus, the objective of this study was to evaluate the influence of light and temperature on the seed germination of H. ringens. The seeds of two lots were sown on a paper substrate and maintained in BOD chambers at temperatures of 15, 20, 25 and 30ºC in the presence and absence of light. The germination speed rate was evaluated every 3 days for 21 days. The experiment was completely randomized with treatments that had a 4 x 2 factorial design. The first visible sign (protrusion of the primary root) of germination was observed seven days after sowing. Germination occurred both in the presence and absence of light and the lowest temperatures significantly influenced the germination process and germination speed. For germinating the species, 15°C was the most favorable temperature compared to 20, 25 and 30°C. It can be concluded that a temperature of 15ºC favors the germination process of H. ringens seeds, which are insensitive to light.(AU)


Subject(s)
Seeds/physiology , Temperature , Germination/physiology , Lamiaceae/physiology , Light Signal Transduction
9.
Biosci. j. (Online) ; 38: e38010, Jan.-Dec. 2022. graf
Article in English | LILACS | ID: biblio-1361645

ABSTRACT

Commercial propagation of pequizeiro, which stands out among the main native fruits of the Cerrado region for its high economic potential, has been done by seeds, despite their erratic germination. The objective of this study was to evaluate the effect of seed size and presence of thorns on the endocarp on seedling emergence of pequizeiro in the field. Seeds were collected in a pequizeiro commercial area in Canarana-MT, Brazil. Due to availability, 2,353 thorny seeds (3 sizes) and 106 seeds without thorns (medium sized) were tested. Thorny seeds were classified as large ­ longer than 50 mm; medium ­ between 40 and 50 mm; small ­ less than 40 mm. Seedling emergence started after 50 days in all seed categories, extending up to 100 days in the large seeds and to about 1 year after sowing in the small and medium sized ones. Small seeds showed a lower rate and speed of emergence compared to the others. Large seeds showed higher emergence speed compared to the medium ones. The presence of thorns did not affect seedling emergence. These results indicate the advantages of pequizeiro seed classification for sowing purposes.


Subject(s)
Germination , Seedlings , Plant Dormancy , Malpighiales
10.
Biosci. j. (Online) ; 38: e38011, Jan.-Dec. 2022. ilus, tab, graf
Article in English | LILACS | ID: biblio-1361647

ABSTRACT

The goal of this study was to determine and correlate the main morphometric characteristics of fruits, seeds, and seedling vigor of Agonandra brasiliensis, in Roraima. The design was completely randomized with three treatments, consisting of six replications with 20 seeds. The treatments established were three classes of seeds: T1 - small seeds (S = 1.50-1.69 g); T2 - medium seeds (M = 1.70-1.89 g) and T3 - large seeds (L = 1.90-2.09 g). The variables evaluated were: length; diameter; the fresh mass of fruits and seeds; percentage, speed (in index) and average time of emergence, length of roots and aerial part; number of leaves; fresh, dry and total seedling mass; seedling lignification index; root/shoot ratio and dry root/shoot ratio and correlations between all studied variables. The fresh mass of the fruit of Agonandra brasiliensis has a high positive correlation with the mass of seeds. Small seeds of Agonandra brasiliensis exhibit a higher percentage of emergence in the conditions of the northern Amazon.


Subject(s)
Seeds/anatomy & histology , Biometry , Seedlings/anatomy & histology , Fruit/anatomy & histology , Germination
11.
Biosci. j. (Online) ; 38: e38061, Jan.-Dec. 2022. tab, graf
Article in English | LILACS | ID: biblio-1396657

ABSTRACT

Solanum capsicoides, commonly known as red soda apple, is a little-studied species with phytotherapeutic characteristics of interest to the pharmaceutical industry. However, little is known about its agronomic characteristics. Therefore, this study aimed to assess the effect of light, different temperatures, and substrates on the germination of S. capsicoides seeds. The study consisted of two experiments: Experiment I - Germination of S. capsicoides seeds under different wavelengths. The seeds were kept on Petri dishes covered with Germitest™ paper moistened with distilled water and exposed to the monochromatic, red, far-red, and dark wavelengths. The experiment was performed in a completely randomized design with four replications of 25 seeds. Experiment II - Germination of S. capsicoides seeds on different substrates and at different temperatures. The seeds were distributed according to six substrates: paper roll, on paper, between sand, on sand, on soil + sand + manure, and between soil + sand + manure. The seeds were also subjected to the constant temperatures of 20, 25, 30, and 35 °C and the alternate temperatures of 20-30, 20-35, 25-30, and 25-35 °C, characterizing a 6 x 8 factorial arrangement. Germination rate, germination speed index, and mean germination time were evaluated. Red soda apple seeds are classified as positive photoblastic, with the highest germination rate occurring at the temperature of 20-35 °C combined with on paper, paper roll, on sand, and between sand substrates.


Subject(s)
Plants, Medicinal , Seeds , Germination , Solanum
12.
Braz. j. biol ; 82: e235475, 2022. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1249240

ABSTRACT

Plants that produce secondary metabolites with allelopathic activity or phytotoxicity can be biotechnologically important, serving as sources of allelochemicals, and thus contributing to the agroindustrial sector. Vismia japurensis (Hypericaceae) is an Amazonian species that grows in clumps called vismiais, from which most other plants are absent. Accordingly, the objective of this study was to identify possible phytotoxicity effects of hexane and methanol extracts of Vismia japurensis leaves and branches in vivo and from seedlings grown in vitro on Lactuca sativa. In addition, fresh and dry leaves were assayed by the sandwich method in order to determine their ability to release allelochemicals. The hexanic extract from in vitro seedlings reduced germination by 10%, while the methanol extract produced a 16% reduction in germination speed. Root growth of Lactuca sativa was inhibited by 64.7% when subjected to hexane leaf extract, by 39.3% under the influence of hexane branch extract, and by 96.09% for in vitro seedling hexanic extract. When analysed by thin layer chromatography and 1H nuclear magnetic resonance, extracts showed evidence of terpenes, anthraquinones and flavonoids, with greater intensity of signals in the aromatic region of in vitro seedling hexanic extract. Clearly, Vismia japurensis has a high biotechnological potential in terms of the production of substances of low polarity with capacity to interfere in plant development.


Plantas que produzem metabólitos secundários com atividade alelopática ou fitotóxica podem ser biotecnologicamente importantes, servindo como fontes de aleloquímicos e, assim, contribuindo para o setor agroindustrial. Vismia japurensis (Hypericaceae) é uma espécie amazônica que cresce em grupos, formando vismiais. Assim, o objetivo deste estudo foi identificar possíveis efeitos fitotóxicos de extratos hexânicos e metanólicos de folhas e ramos de Vismia japurensis in vivo e de plântulas cultivadas in vitro sobre Lactuca sativa. Além disso, folhas frescas e secas foram analisadas pelo método sanduíche, a fim de determinar sua capacidade de liberação de aleloquímicos. O extrato hexânico de plântulas in vitro reduziu a germinação em 10% e o extrato metanólico promoveu uma redução de 16% na velocidade de germinação. O crescimento radicular de Lactuca sativa foi inibido em 64,7% quando submetido ao extrato hexânico das folhas, em 39,3% sob influência do extrato hexânico dos galhos e em 96,09% para o extrato de hexânico das plântulas in vitro. Quando analisados por cromatografia em camada delgada e ressonância magnética nuclear de 1H, os extratos mostraram evidências de terpenos, antraquinonas e flavonoides, com maior intensidade de sinais na região aromática do extrato hexânico das plântulas in vitro. Assim, Vismia japurensis possui elevado potencial biotecnológico em termos de produção de substâncias de baixa polaridade com capacidade de interferência no desenvolvimento de plantas.


Subject(s)
Germination , Clusiaceae , Plant Extracts/toxicity , Plant Leaves , Seedlings , Allelopathy
13.
Braz. j. biol ; 82: e231957, 2022. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1249251

ABSTRACT

Essential oils from the stems and leaves of Croton doctoris were analyzed by gas chromatography and mass spectrometry, resulting in 22 identified compounds. The effects of these essential oils on the germination, root and shoot growth, total chlorophyll content, potential root respiration, peroxidase activity, catalase, superoxide dismutase, and mitotic index in lettuce and onion were determined. Antioxidant, antimicrobial, and cytotoxic activity were also investigated. The results revealed that the stem oil consisted of 15 compounds, of which caryophyllene oxide (24.5%) and E-caryophyllene (13.3%) were the major constituents. The leaf oil contained E-caryophyllene (39.6%) and α-humulene (13.2%) as major compounds. The oils inhibited the germination and growth of lettuce and onion seedlings and reduced chlorophyll content, root respiration, and cell division. They also caused oxidative stress, indicated by the increased activity of the evaluated antioxidant enzymes. These abnormal physiological processes contributed to the inhibition of plant growth. The most pronounced phytotoxic effects were observed in the stem oil. The cytotoxicity tests indicated that leaf oil was more active than stem oil, resulting from the presence of biologically active sesquiterpenes that inhibit the growth of cancer cells.


Os óleos essenciais do caule e da folha de Croton doctoris foram analisados por cromatografia gasosa (GC) e espectrometria de massa (GC-MS) resultando em 22 compostos identificados. Os efeitos dos óleos essenciais na germinação, crescimento de raízes e parte aérea, teor total de clorofila, respiração radicular, atividade de peroxidase, catalase e superóxido de dimetase e índice mitótico foram determinados em alface e cebola. Atividade antioxidante, antimicrobiana e citotóxica também foram investigadas. Os resultados revelaram que o óleo do caule é constituído por 15 compostos, dos quais os principais são o óxido de cariofileno (24,5%) e E-cariofileno (13,3%). O óleo foliar apresentou E-cariofileno (39,6%) seguido de α-humuleno (13,2%) como compostos majoritários. Os óleos inibiram a germinação e o crescimento das plântulas de alface e cebola e reduziram o conteúdo de clorofila, a respiração radicular e a divisão celular. Eles também causaram estresse oxidativo, indicado pelo aumento da atividade das enzimas antioxidantes avaliadas. Esses processos fisiológicos anormais contribuem para a inibição do crescimento das plantas. Os efeitos fitotóxicos mais pronunciados foram observados no óleo do caule. Nos testes de citotoxicidade observou-se que o óleo das folhas foi mais ativo, resultante da presença de sesquiterpenos biologicamente ativos que atuam inibindo o crescimento das células cancerígenas.


Subject(s)
Oils, Volatile/toxicity , Euphorbiaceae , Croton , Plant Oils , Plant Leaves , Lactuca , Germination
14.
Braz. j. biol ; 82: e233547, 2022. graf
Article in English | LILACS, VETINDEX | ID: biblio-1249284

ABSTRACT

Salvia hispanica cultivation is recent in Brazil and occurs in the off-season, when there is lower water availability in the soil. Water deficit is one of the abiotic factors that most limit germination for compromising the sequence of metabolic events that culminate with seedling emergence. Several attenuating substances have been used to mitigate the effects resulting from this stress and give higher tolerance to the species. Thus, the objective of this study was to evaluate the action of different agents as water stress attenuators in the germination and accumulation of organic compounds in S. hispanica seedlings. The treatments consisted of pre-soaking the seeds for 4 hours in salicylic acid (1 mM.L-1), gibberellic acid (0.4 mM.L-1), distilled water and control treatment (without soaking). The seeds were germinated at osmotic potentials of 0.0, -0.1, -0.2, -0.3 and -0.4 MPa, using PEG 6000 as an osmotic agent. The variables germination percentage, germination speed index, shoot and primary root lengths, total dry mass, proline, total soluble sugars and total free amino acids were analyzed. Salicylic acid and gibberellic acid led to the best results among the attenuators tested, increasing germination, length, dry mass and biochemical components of S. hispanica seedlings under water deficit. Therefore, salicylic and gibberellic acids are efficient in mitigating water stress in S. hispanica seeds up to the potential of -0.4 MPa.


O cultivo da Salvia hispanica é recente no Brasil e se dá no período de entressafra, quando há menor disponibilidade hídrica no solo. O déficit hídrico é um dos fatores abióticos que mais limitam a germinação por comprometer a sequência de eventos metabólicos que culminam com a emergência da plântula. Diversas substâncias atenuadoras têm sido empregadas com a finalidade de mitigar os efeitos resultantes desse estresse e conferir maior tolerância às espécies. Desse modo, objetivou-se avaliar a ação de diferentes agentes como atenuadores do estresse hídrico na germinação e acúmulo de compostos orgânicos em plântulas de S. hispanica. Os tratamentos consistiram na pré-embebição das sementes durante 4 horas em ácido salicílico (1 mM.L-1), ácido giberélico (0,4 mM.L-1), água destilada e o tratamento controle (sem embebição). As sementes foram germinadas sob os potenciais osmóticos 0,0, -0,1, -0,2, -0,3 e -0,4 MPa, utilizando PEG 6000 como agente osmótico. Analisaram-se as variáveis porcentagem de germinação, índice de velocidade de germinação, comprimento da parte aérea e da raiz primária, massa seca total, prolina, açúcares solúveis totais e aminoácidos livres totais. O ácido salicílico e o ácido giberélico apresentaram os melhores resultados, dentre os atenuadores testados, incrementando a germinação, o comprimento, a massa seca e os componentes bioquímicos de plântulas de S. hispanica sob déficit hídrico. Logo, os ácidos salicílico e giberélico são eficientes na mitigação do estresse hídrico em sementes de S. hispanica até o potencial -0,4 MPa.


Subject(s)
Salvia , Dehydration , Seeds , Stress, Physiological , Brazil , Water , Germination , Seedlings
15.
Semina ciênc. agrar ; 43(2): 509-522, mar.-abr. 2022. ilus, tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1368814

ABSTRACT

Seed quality is routinely assessed by direct tests, e.g, the germination test, or indirect tests like the tetrazolium test, which has shoown to be promising in the determine viability and vigor, allowing the diagnosis of the main problems that may affect seed quality, such as mechanic damages, field deterioration and storage. In this respect, this study was conducted to develop a tetrazolium test protocol to evaluate the viability and vigor of Tamarindus indica L. seeds. Before exposing the seeds to the tetrazolium solution, seed preconditioning studies were carried out in which seven soaking times were tested. The soaking time that did not cause damage to the seed embryo and allowed the removal of the seed coat to expose the seed structures to the tetrazolium salt was selected. Then, an experiment was set up in a completely randomized design with a 2x3x3 factorial arrangement involving two seed lots, three soaking times in tetrazolium salt (6, 12 and 16 h) and three salt concentrations (0.075, 0.1 and 0.5%), totaling 18 treatments with four replicates of 25 seeds, evaluated at 40 ºC. For each treatment, the seeds were divided into three classes, namely, viable and vigorous embryos (class 1); viable embryos (class 2) and non-viable or dead embryos (class 3). For a comparison with the tetrazolium test results, the two seed lots were analyzed for water content, germination, emergence, first count, germination speed index, emergence speed index, growth and seedling dry weight. The viability and vigor of T. indica seeds can be evaluated after a soaking period of 48 h and immersion for 6h in tetrazolium salt at the concentration of 0.1%, at 40°C, with provides results similar to conventional seed viability tests. The tetrazolium test proved to be adequate to differentiate T. indica seed lots in terms of viability.(AU)


A qualidade das sementes é avaliada rotineiramente por testes diretos como o de germinação e indiretos como o teste de tetrazólio que tem se mostrado promissor na determinação da viabilidade e vigor possibilitando o diagnóstico dos principais problemas que podem afetar a qualidade das sementes, como danos mecânicos, deterioração de campo e armazenamento. Neste sentido, objetivou-se com este trabalho desenvolver um protocolo do teste de tetrazólio para avaliar a viabilidade e o vigor das sementes de Tamarindus indica L. Antes da exposição das sementes a solução de tetrazólio, foram realizados estudos pre-condicionamento das sementes utilizando sete períodos de embebição sendo selecionado o tempo que não causou danos ao embrião da semente e permitiu a remoção do tegumento para exposição das estruturas da semente ao sal de tetrazólio. Em seguida, o experimento foi instalado em delineamento inteiramente casualizado em esquema fatorial 2x3x3, sendo dois lotes de sementes, três tempos de embebição em sal (6; 12 e 16 horas) e três concentrações de sal de tetrazólio (0,075; 0,1 e 0,5%), totalizando dezoito tratamentos com quatro repetições de 25 sementes, avaliados a 40 ºC. Para cada tratamento as sementes foram divididas em três classes: embriões viáveis e vigorosos (classe 1); embriões viáveis (classe 2) e embriões inviáveis ou mortos (classe 3). Para comparar com o resultado do teste de tetrazólio os dois lotes de sementes foram submetidos a análise de teor de água, germinação, emergência, primeira contagem e índice de velocidade de germinação e emergência, crescimento e massa seca de plântulas. A viabilidade e o vigor das sementes de T. indica podem ser avaliados após um período de 48h de embebição e 6h de imersão na concentração de 0,1% de sal de tetrazólio a 40 ºC, com resultados semelhantes aos testes convencionais de determinação da viabilidade das sementes. O teste de tetrazólio mostrou-se adequado para diferenciar a viabilidade em relação aos lotes de sementes de T. indica.(AU)


Subject(s)
Seeds/physiology , Germination , Tamarindus/physiology
16.
Chinese Journal of Biotechnology ; (12): 252-263, 2022.
Article in Chinese | WPRIM | ID: wpr-927709

ABSTRACT

Cultivating salt-alkali tolerant rice varieties is one of the important ways to meet the increasing food demand of growing global population. In this study, twenty-one rice germplasms with different salt-alkali tolerance were treated with six salt-alkali concentrations at germination and seedling stages. The germination potential, germination rate, shoot length, root length, root number, fresh weight of shoot and seedlings were measured. The average value of salt damage rate was used to evaluate the salt-alkali tolerance. As the salt-alkali concentration increases, the inhibition on seed germination and growth became more obvious. Upon treatment with 1% NaCl plus 0.25% NaHCO3, the salt damage rate of germination rate has the largest variation, ranging from 0% to 89.80%. The salt damage rate of each trait shows a similar trend at all concentrations. Four germplasm resources with strong salt-alkali tolerance (Dajiugu, Nippobare, Mowanggu and 02428) and 7 sensitive germplasms were screened. The salt-tolerant gene sequence of 4 salt-alkali tolerant varieties and 3 sensitive germplasms were analyzed. OSHAL3 and OsRR22 were identical among the 7 germplasms, but SKC1 and DST showed clear variations between the salt-alkali tolerant and sensitive germplasms. Besides the salt-alkali tolerant germplasm resources, this study can also serve as a reference for mining of genes involved in salt-alkali tolerance and breeding of salt-alkali tolerant rice varieties.


Subject(s)
Alkalies , Germination , Oryza/genetics , Plant Breeding , Seedlings/genetics
17.
Chinese Journal of Biotechnology ; (12): 77-88, 2022.
Article in Chinese | WPRIM | ID: wpr-927694

ABSTRACT

Seed quality plays an important role in the agricultural and animal husbandry production, the effective utilization of genetic resources, the conservation of biodiversity and the restoration and reconstruction of plant communities. Seed aging is a common physiological phenomenon during storage. It is a natural irreversible process that occurs and develops along with the extension of seed storage time. It is not only related to the growth, yield and quality of seed and seedling establishment, but also has an important effect on the conservation, utilization and development of plant germplasm resources. The physiological mechanisms of seed aging are complex and diverse. Most studies focus on conventional physiological characterization, while systematic and comprehensive in-depth studies are lacking. Here we review the recent advances in understanding the physiology of seed aging process, including the methods of seed aging, the effect of aging on seed germination, and the physiological and molecular mechanisms of seed aging. The change of multiple physiological parameters, including seed vigor, electrical conductivity, malondialdehyde content and storage material in the seed, antioxidant enzyme activity and mitochondrial structure, were summarized. Moreover, insights into the mechanism of seed aging from the aspects of transcriptome, proteome and aging related gene function were summarized. This study may facilitate the research of seed biology and the conservation and utilization of germplasm resources.


Subject(s)
Germination , Plants , Proteome , Seedlings , Seeds/genetics
18.
Arch. latinoam. nutr ; 71(4): 241-251, dic. 2021. tab
Article in Spanish | LILACS, LIVECS | ID: biblio-1355032

ABSTRACT

El basul es el fruto de la planta Erythrina edulis que posee un alto contenido de proteínas, fibra dietética y antioxidantes, pero también con contenido de antinutrientes. Objetivo. El objetivo del estudio fue evaluar el efecto del germinado sobre las características nutricionales, propiedades bioactivas y funcionales de las semillas de basul. Materiales y métodos. Mediante un diseño aleatorizado con arreglo factorial de 2x2x2 (tiempo de remojo, tiempo de germinado, presencia o ausencia de luz), las semillas de basul fueron germinadas y convertidas en harina (HBG) para determinar la composición proximal y la digestibilidad in vitro de la proteína. Además, se ha determinado los fenoles totales (CFT), la capacidad antioxidante (métodos ABTS y DPPH) y las propiedades de hidratación y adsorción de aceite. Resultados. Las diferentes condiciones de germinado no han modificado la composición proximal de la HBG; sin embargo, la digestibilidad in vitro de la proteína incrementó hasta en 6,25% en uno de los tratamientos respecto a la muestra no germinada. El CFT, también ha incrementado de 241,49 mg AGE/100g (sin germinar) a 267,15 mg AGE/100g (germinado); al igual que la capacidad antioxidante (ABTS) de 173,04 µmolTE/g (sin germinar) a 195,67 µmolTE/g (germinado). También se tuvo incrementos en la solubilidad, la capacidad de absorción de agua y la capacidad de hinchamiento. Conclusión. La calidad de la proteína, el contenido de fenoles totales, la capacidad antioxidante y propiedades funcionales de interacción con el agua de la semilla de basul mejora con el germinado(AU)


Basul is the fruit of the Erythrina edulis plant. It has a high content of proteins, dietary fiber, and antioxidants, but it also contains antinutrients. Objective. The study objective was to evaluate the effect of sprouting on the nutritional characteristics, bioactive and functional properties of basul seeds. Materials and methods. Basul seeds were germinated to produce flour (HBG) and determine its proximal composition and in vitro digestibility of the protein through a randomized design with a 2x2x2 factorial arrangement (soaking time, germination time, and presence or absence of light). Total phenols (CFT), antioxidant capacity (ABTS and DPPH methods), and hydration and oil adsorption properties were also determined. Results. The different germination conditions did not modify the proximal composition of HBG. However, the in vitro digestibility of the protein increased up to 6.25% in one of the treatments compared to the non-germinated sample. The CFT also increased from 241.49 mg AGE/100g (without germination) to 267.15 mg AGE/100g (germinated) and the antioxidant capacity (ABTS) from 173.04 µmolTE/g (without germination) to 195.67 µmolTE/g (germinated). Solubility, water absorption capacity, and swelling capacity also increased. Conclusion. The quality of the protein, the content of total phenols, the antioxidant capacity, and the functional properties of interaction with the water of the basul seed improved with germination(AU)


Subject(s)
In Vitro Techniques , Dietary Fiber , Dietary Proteins , Germination , Erythrina , Phenolic Compounds , Flour/analysis , Proteins , Absorption , Fabaceae , Antioxidants , Nutritive Value
19.
Rev. biol. trop ; 69(3)sept. 2021.
Article in English | LILACS, SaludCR | ID: biblio-1387672

ABSTRACT

Abstract Introduction: H. perotensis is a plant with a high potential for ecological restoration because it yields thousands of seeds and grows under low levels of rain, poor soils and contrasting temperatures. However, little is known of the seed mass maturity (high seed germination, low seed fresh weight and low seed moisture content) in this species. Objective: Assess seed germination in the laboratory of H. perotensis during seed development and along the floral stalk (infructescence) in two sites one in rocky location and another near a lake. The hypothesis was that there is a time after flowering in which seeds have highest germination and fresh weight and that the apical, centre and base of the infructescence are different in seed germination and fresh weight in both sites. Methods: Capsules were collected in two sites one in rocky land (Frijol Colorado, Perote, Veracruz) and another near one lake (Alchichica, Puebla), in the months of August, September and November 2016 and January 2017. A repeated measure design (RMD) was used to analyze the effects of infructescence section on seed weight, moisture content and seed germination (41, 87, 152 and 215 days after flowering). Each evaluation time comprised five replicates, each one with 15 seeds. Results: Difference in seed germination, seed weight and moisture content between sections of the infructescence was not significant. However, significant differences were found not only between first and last sample dates, but mainly between first and second dates. Eighty-seven days after flower pollination seed moisture content was lower than 20 % and up to 80 % of seed germinated in both sites of sampling. Conclusions: In this study it was found that the moisture content of H. perotensis seed can be used as an indicator of the physiological maturity of the seed and it is also related to germination of the seed.


Resumen Introducción: H. perotensis es una planta con un alto potencial para la restauración ecológica debido a que produce miles de semillas y crece con niveles bajos de lluvia, suelos pobres y temperaturas contrastantes. Sin embargo, el desarrollo de la madurez de las semillas (germinación alta, baja humedad y bajo peso fresco de semilla) en esta especie es muy poco conocido. Objetivo: Evaluar la germinación en el laboratorio de las semillas de H. perotensis, durante el desarrollo de la semilla y a lo largo del tallo floral (infrutescencia) en dos sitios; uno en un área rocosa y otro cerca de un lago. La hipótesis fue que hay un tiempo después de la floración, en el que las semillas presentan la mayor germinación y menor peso fresco, y que las secciones apical, central y base de la infrutescencia, la germinación y el peso fresco de la semilla son diferentes en los dos sitios. Métodos: se recolectaron las cápsulas en dos sitios uno en un área rocosa (Frijol Colorado, Perote, Veracruz) y otro cerca de un lago (Alchichica, Puebla), en los meses de Agosto, Septiembre y Noviembre de 2016 y Enero de 2017. Se usó un diseño de medidas repetidas (DMR) para analizar los efectos de la sección de la infrutescencia sobre el peso fresco de la semilla, el contenido de humedad y la germinación de la semilla (41, 87, 152 y 215 días, después de la floración). Cada tiempo de evaluación comprendió cinco réplicas y 15 semillas. Resultados: La diferencia en la germinación de la semilla, el peso de la semilla y el contenido de humedad entre las secciones de la infrutescencia no fue significativa. Sin embargo, se encontraron diferencias significativas entre las fechas de muestreo inicial y final, pero sobre todo entre la primera y la segunda fecha. Asimismo, ochenta y siete días después de la polinización de las flores, el contenido de humedad de las semillas fue inferior al 20 % y superior al 80 % en la germinación de las semillas en ambos sitios de muestreo. Conclusiones: en este estudio se encontró que el contenido de humedad de la semilla de H. perotensis, puede usarse como un indicador de la madurez fisiológica de la semilla y también está relacionado con la germinación de la semilla.


Subject(s)
Germination , Bromeliaceae , Bromelia , Mexico
20.
Braz. j. biol ; 81(3): 650-656, July-Sept. 2021. tab, graf
Article in English | LILACS | ID: biblio-1153376

ABSTRACT

Abstract Light is considered a factor that influences the seed germination of many weed species, and it can signal whether the environmental conditions are favorable or are not favorable for germination. We aimed to study if there is an influence of light quality and dormancy overcoming in seed germination of Echium plantagineum L. We carried out a 2 x 6 factorial experiment, with and without dormancy overcoming with potassium nitrate followed by immersion in gibberellic acid; six light qualities, obtained through the light filters: blue, green, red, far-red, white light and absence of light. The evaluations performed were germination speed index (GSI), average germination time (AGT), germination at the four and 14 days after seeding (DAS), accumulated germination and relative frequency of germination. We observed significant interaction among the light qualities and seed dormancy overcoming or not for the studied variables. There was no significant effect of light qualities, in the evaluated variables, when performing dormancy overcoming, presenting germination above 90% in all the light qualities. However, without dormancy overcoming, we observed greater GSI, germination at four and 14 DAS for the red light filter with 5, 4, 29 and 45%, respectively. When the seeds were submitted to the absence of light, and without dormancy overcoming, there was only 7% of germination at 14 DAS. The seeds of E. plantagineum presented greater germination under incidence of red light, without dormancy overcoming, being classified as preferably positively photoblastics, provided that the dormancy is not overcome.


Resumo A luz é considerada um fator que influencia a germinação das sementes de muitas espécies de plantas daninhas, podendo sinalizar se as condições ambientais são favoráveis ou não para a germinação. Objetivou-se estudar se há influência da qualidade da luz e superação de dormência na germinação de sementes de Echium plantagineum L. Realizou-se um experimento fatorial 2 x 6, com e sem superação de dormência com nitrato de potássio seguido pela imersão em ácido giberélico; seis qualidades de luz, obtidas através de filtros de luz: azul, verde, vermelho, vermelho-distante, luz branca e ausência de luz. As avaliações realizadas foram índice de velocidade de germinação (IVG), tempo médio de germinação (TMG), germinação aos quatro e 14 dias após a semeadura (DAS), germinação acumulada e frequência relativa de germinação. Observou-se interação significativa entre as qualidades de luz e a superação ou não de dormência das sementes para as variáveis estudadas. Não houve efeito significativo das qualidades de luz, nas variáveis avaliadas, ao realizar superação de dormência, apresentando germinação acima de 90% em todas as qualidades de luz. Todavia, sem superação de dormência, observou-se maior IVG, germinação aos quatro e 14 DAS para o filtro de luz vermelha com 5,4, 29 e 45%, respectivamente. Quando as sementes foram submetidas à ausência de luz, e sem superação de dormência, houve apenas 7% de germinação aos 14 DAS. As sementes de E. plantagineum apresentam maior germinação sob incidência de luz vermelha, sem superação de dormência, sendo classificadas como fotoblásticas positivas preferenciais, desde que não seja superada a dormência.


Subject(s)
Boraginaceae , Echium , Seeds , Germination , Plant Dormancy
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