Dependência térmica da germinação de sementes de Drymaria cordata (L.) Willd. ex Roem. &amp; Schult. (Cariophyllaceae)

Cardoso, Victor José Mendes

doi:10.1590/s0102-33062009000200002

Cited by 11 publications

(12 citation statements)

References 19 publications

(22 reference statements)

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“…Some studies evaluated the role of Ψ on seed germination of Brazilian species (Botelho and Perez, 2001;Fonseca and Perez, 2003;Rego et al, 2007), but rarely explaining whether germination would fit the presupposes of hydrotime models (Cardoso and Pereira, 2008;Oliveira et al, 2019). Most attention regards to the role of temperature, rather than water potential, as described by thermal time models in neotropical species (Cardoso and Pereira, 2009;Pires et al, 2009;Daibes and Cardoso, 2018;Duarte et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

Effect of reduced water potential on seed germination of a forest tree: a hydrotime approach

Daibes

Cardoso

2020

J. Seed Sci.

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Hydrotime (θH) models provide information on seed tolerance to low water potential and time to germination under different conditions. Here it was evaluated the capacity of graphic and probit model to describe germination parameters and germination times (t) in a tropical legume (Peltophorum dubium). Germination tests were conducted under reduced water potentials (polyethylene glycol solutions from 0 to -1.2 MPa) at 25 °C. Regression lines were applied to investigate the relationship between germination rates (1/t) and water potential for different germination percentages (fractions 10, 30, 50 and 70%). Those regressions were used in the graphic model to calculate θH (1/slope) and determine the base water potential (Ψb) as the point which the line intercepts the x-axis (G% = 0). In the probit model, germination percentages were transformed to probit units and plotted against Ψb-values to describe germination response under a single regression line. Values for θH varied from 1.8 to 2.0 MPa day in both models, and Ψb showed a normal distribution, as presupposed by the probit model. Predicted germination times (t10 and t50) mostly fell within observed times, thus showing biological relevance of the models to describe the effects of water potential on seed germination.

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Section: Introductionmentioning

confidence: 99%

Effect of reduced water potential on seed germination of a forest tree: a hydrotime approach

Daibes

Cardoso

2020

J. Seed Sci.

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“…A faixa térmica adequada para a germinação de sementes de espécies tropicais está, frequentemente, entre 20 e 30 °C (Borges & Rena 1993;Bilia et al 1998;Santos et al 2004;Mello & Barbedo 2007;Stockman et al 2007;Coelho et al 2008;Cardoso & Pereira 2009;Pires et al 2009;Pimenta et al 2010). Contudo, podem ocorrer variações até dentro da mesma espécie, provavelmente devido à variação de fatores ambientais, principalmente a temperatura do ar, tipicamente relatada como acúmulo de graus-dia.…”

Section: Introductionunclassified

Limites térmicos para a germinação em função da origem de sementes de espécies de Eugenia (Myrtaceae) nativas do Brasil

Lamarca¹,

Silva²,

Barbedo³

2011

Acta Bot. Bras.

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Limites térmicos para a germinação em função da origem de sementes de espécies de Eugenia (Myrtaceae) nativas do Brasil RESUMO (Limites térmicos para a germinação em função da origem de sementes de espécies de Eugenia (Myrtaceae) nativas do Brasil). A germinação das sementes é dependente de numerosos fatores abióticos, dentre os quais a temperatura fi gura entre os principais. No presente estudo analisou-se o comportamento germinativo de sementes de E. brasiliensis, E. involucrata, E. pyriformis e E. unifl ora em resposta a diferentes condições de luz e temperatura, incluindo-se o cálculo da soma térmica durante o desenvolvimento e maturação das sementes. Os resultados demonstraram que a germinação de sementes e o desenvolvimento de plântulas normais ocorreram adequadamente na faixa de 20 °C a 30 °C. Nessa faixa, as sementes foram indiferentes à luz e à alternância de temperatura para a germinação. Especificamente para Eugenia pyriformis, avaliaram-se temperaturas superiores a 30 °C e inferiores a 20 °C, verifi cando-se que as sementes germinaram na faixa térmica de 10 °C a 35 °C, mas não a 5 °C e a 40 °C; os maiores valores de germinação e de IVG foram observados a 25 °C e 30 °C. Ficou evidente que a secagem modifi ca os limites e exigências térmicas para a germinação das sementes de E. pyriformis, uma vez que os maiores níveis de desidratação resultaram em maiores prejuízos à germinação fora da faixa térmica ótima. As sementes de E. pyriformis coletadas em Lavras, MG, que receberam maior quantidade de graus-dia durante o desenvolvimento e a maturação, apresentaram melhor desempenho em relação às sementes coletadas em Campinas, SP e em São Paulo, SP. Palavras-chave: graus-dia, luz, Myrtaceae, temperaturaEdmir Vicente Lamarca 1,4 , Cristiana Vendrame e Silva 2 e Claudio José Barbedo 3 ABSTRACT (Th ermal requirements for the seeds of Brazilian species of Eugenia (Myrtaceae) according to their origin). Seed germination is dependent on several abiotic factors including temperature. In this study, we analyzed the germination of seeds of Eugenia brasiliensis, E. involucrata, E. pyriformis and E. unifl ora in response to diff erent conditions of light and temperature. Seeds of all species showed high germination values from 20 to 30 °C. Germination of seeds of E. Pyriformis was also evaluated at temperatures higher than 30 °C and lower than 20 °C. Th e germination and the normal seedling development occurred from 10 °C to 35 °C, not at 5 °C and 40° C. Results also showed that desiccation changed the limits for germination in E. Pyriformis since the most dehydrated seeds had the highest damaged in germination at suboptimal temperatures. Th ermal time during development and maturation of seeds was also considered. Th e seeds of E. pyriformis from Lavras, MG, which received the greatest number of degree-days during development and maturation, showed better performance than the seeds from Campinas, SP and São Paulo, SP.

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“…Dung beetles use both fruits and mammalian dung as fodder and oviposition sites (Cambefort & Walter 1991;Hanski 1991;Halffter & Matthews 1966), acting as secondary dispersers and positively affecting seed survival by preventing predation (Wicklow et al 1984;Estrada & Coates-Estrada 1991;1996). The minimum temperature for A. arenaria germination was 20 ºC (2.7 %), with the greatest germination rate at 35 ºC (40 %), unusually high compared to other tropical species (Mello & Barbedo 2007;Cardoso & Pereira 2009;Pires et al 2009;Pimenta et al 2010). Optimum temperature for germination corresponds to temperatures usually experienced at the time of seedling emerge (Baskin & Baskin 2014;Bell et al 1993) which in A. arenaria is the summer period, when water availability is greatest.…”

Section: Discussionmentioning

confidence: 94%

Disentangling plant establishment in sandy coastal systems: biotic and abiotic factors that determine Allagoptera arenaria (Arecaceae) germination

et al. 2017

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Germination rate and establishment success of plants in harsh environments depend on the ability of seeds to withstand unfavorable environmental conditions and avoid predators. Brazilian coastal plains, known as restinga, are subject to environmental factors that seriously limit plant establishment and survival (e.g. salinity, desiccation, oligotrophy, fl ooding, high temperature and radiation levels). We tested, both in fi eld and laboratory experiments, conditions for germination and establishment of Allagoptera arenaria, a palm tree often found in restinga ecosystems of southeastern Brazil, and which have a principal role in plant community dynamics. Our results showed that the absence of mesocarp, high radiation exposure, and temperature were the main drivers of seed germination. In the fi eld, the highest germination rate was linked to nude seeds buried in open areas. High temperatures and/or predation damaged seeds that remained on the soil surface, especially if they were close to the mother plant and alongside dung piles made by dispersers. Under controlled conditions, seeds exhibited optimum germination at 35 ºC. Th erefore, the germination and establishment of A. arenaria depend as much on environmental conditions as on a network of interactions including vertebrates and invertebrates, which allow this species to colonize harsh, open areas in restinga ecosystems.

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Dependência térmica da germinação de sementes de Drymaria cordata (L.) Willd. ex Roem. & Schult. (Cariophyllaceae)

Cited by 11 publications

References 19 publications

Effect of reduced water potential on seed germination of a forest tree: a hydrotime approach

Effect of reduced water potential on seed germination of a forest tree: a hydrotime approach

Limites térmicos para a germinação em função da origem de sementes de espécies de Eugenia (Myrtaceae) nativas do Brasil

Disentangling plant establishment in sandy coastal systems: biotic and abiotic factors that determine Allagoptera arenaria (Arecaceae) germination

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