O objetivo deste trabalho foi determinar a metodologia mais adequada para superação de dormência das sementes de Parkia gigantocarpa Ducke e produção de mudas. As sementes foram submetidas aos seguintes tratamentos: imersão em água fervente à temperatura de 100 ºC, por 10 minutos; escarificação ácida, com imersão em ácido sulfúrico (H 2 SO 4) a 98 %, por 5, 10, 20, 30 e 40 minutos; escarificação mecânica, com abrasão em lixa n o 80 por 15 segundos, e testemunha (sem tratamento). Também foi realizada a avaliação da qualidade das mudas através da massa seca das raízes primárias. O delineamento experimental foi inteiramente casualizado, com oito métodos de superação de dormência. Levando-se em consideração todos os parâmetros avaliados, os resultados indicaram que a escarificação ácida por 30 e 40 minutos foram os métodos mais eficientes para a superação da dormência das sementes de Parkia gigantocarpa, proporcionando maior vigor na germinação e maiores médias de massa seca para as raízes primárias. Palavras-chave: espécies florestais; sementes nativas; faveira.
Understanding how germination traits can influence the distribution pattern of adult plants is still an important issue for seed ecologists and biologists. Here, we evaluated if seed germination responses to abiotic factors may be related to the occurrence of two Moquiniastrum species in different phytophysiognomies from the Brazilian savanna. To evaluate if germination responses are distinct between species, seeds of M. barrosoae (common to typical savanna) and M. polymorphum (common to typical and forested savanna) were set to germinate under different constant (5 to 40 • C) and alternating (15-30, 20-30, 25-30 and 25-35 • C) temperature regimes in light and dark conditions, different red:far-red ratios (0.1, 0.5, 2.0 and 7.2 R:FR) of light, and water availability (0 to −1.0 MPa) in controlled experiments. Seed germination responses were distinct between species, with M. polymorphum presenting higher germinability over a wider temperature range, with lower light requirement for germination, less sensitivity to alteration of R:FR ratios and higher tolerance to water limitation compared to M. barrosoae, which presented more specific environmental requirements to seed germination. Therefore, we demonstrate that seed germination responses may contribute to the distribution pattern observed in adult plants, since the more widely distributed species (M. polymorphum) presented higher germinability over a broader range of environmental conditions, which may enable this species to occur in different phytophysiognomies compared to the species with the more restricted distribution area (M. barrosoae).
ABSTRACT. Diptychandra aurantiaca is a tree belonging to the Fabaceae family. The wood of this tree is moderately heavy and resistant, and it is used to make posts, wooden sleepers and building, among other structures. The aim of this work was to evaluate seed germination and the initial growth of the primary roots in D. aurantiaca at different temperatures using seeds collected in the village of Taboco in Mato Grosso do Sul state, Brazil. The seeds were subjected to constant temperatures of 20, 25, 30 and 35°C and alternating temperatures of 20-30 and 25-35°C using four replications of 25 seeds per treatment in a germination chamber. The results showed that most seeds germinated at 25 and 30°C, with 97 and 87%, respectively, thus indicating that these temperatures are efficient to not only promote germination but also to potentiate the speed (1,1 -25 and 30°C) and decrease the average germination time (9.0 -25°C and 7.1 -30°C), highest allocation of dry biomass (0.0067 g at 25°C and 0.0055 g at 30°C) and the greatest primary root size (17.5 mm at 25°C and 16.5 mm at 30°C).Keywords: broad-leafed, semi-deciduous, savannah (Cerrado), forest seeds, 'true-red-charcoal'.Efeito da temperatura sobre a germinação de sementes de Diptychandra aurantiaca (Fabaceae) RESUMO. Diptychandra aurantiaca é uma árvore da família Fabaceae. Como utilidade, a madeira, moderadamente pesada e resistente, é utilizada na fabricação de postes, dormentes, construção civil, entre outros usos. O objetivo deste trabalho foi avaliar a germinação das sementes e crescimento da raiz primária em diferentes temperaturas, com sementes coletadas na região do Taboco, Mato Grosso do Sul. As sementes foram submetidas a temperaturas constantes de 20, 25, 30 e 35°C e alternadas de 20-30 e 25-35°C, com quatro repetições de 25 sementes por tratamento em câmaras de germinação. Os resultados obtidos evidenciaram maior percentagem de germinação das sementes nas temperaturas de 25 e 30°C, atingindo 97 e 87%, respectivamente, indicando que estas temperaturas são mais eficazes em promover a germinação, propiciando também maior velocidade de germinação (1,1 -25 e 30°C), menor tempo médio de germinação (9,0 -25°C e 7,1 -30°C), maior alocação de massa seca (0,0067 g a 25°C e 0,0055 g a 30°C) e comprimento da raiz primária (17,5 mm em 25°C e 16,5 mm em 30°C).Palavras-chave: florestas latifoliadas, semidecíduas, cerradão, sementes florestais, carvão-vermelho-verdadeiro.
Parkia gigantocarpa is a valuable timber tree, and due to its rapid growth and great survival can be used to enrich forest clearings. The aims of this study was describe main morphological characters of seeds and seedlings, and to evaluate germination and initial growth of the species at six temperatures. The seed shape varies from elliptical, oblong or ovoid with bone consistency surface, smooth, glossy black color and presence of pleurogram. Average dimensions were 21.25 mm (length), 10.43 mm (width), and 6.15 mm (thickness). The embryo type is linear axial, with fleshy cotyledons, convex planes and dominant. The germination is epigeous phanerocotyledonary with fleshy cotyledons, and occurs between the second and fifth days after sowing. The fully developed seedling stage was reached on the fifteenth day after sowing. Temperatures of 30 and 35 C provided higher germination rates in less time and with higher root biomass allocation.Keywords: Amazon; biometrics; germination temperature; fava-atanã; forest seeds. ResumoGerminação e morfologia de sementes e plântulas de Parkia gigantocarpa Fabaceae: Mimosoidae. Parkia gigantocarpa é uma árvore de interesse madeireiro, indicada para o enriquecimento de clareiras devido seu rápido crescimento. Os objetivos deste trabalho foram descrever os principais caracteres morfológicos de sementes e plântulas, e avaliar a germinação de sementes e desenvolvimento inicial da espécie em seis temperaturas. As sementes apresentam formato que varia de elíptica, ovóide ou oblonga com superfície de consistência óssea, lisa, brilhosa de coloração negra e presença de pleurograma, com dimensões médias de 21,25 mm de comprimento, 10,43 mm de largura, e 6,15 mm de espessura. O embrião é do tipo axial linear, com cotilédones crassos, plano convexos e dominantes. A germinação é epígea fanerocotiledonar com cotilédones carnosos, e ocorre entre o segundo e quinto dias após semeadura, sendo que o estágio de plântula completamente formada é alcançado no décimo quinto dia após a semeadura. As temperaturas de 30 e 35 ºC proporcionaram elevadas taxas de germinação em menor tempo e com maior alocação de biomassa radicular.Palavras-chave: Amazônia; biometria; temperatura para germinação; fava-atanã; sementes florestais.
Germinação de sementes de paineira-do-campo (Eriotheca gracilipes (K. Schum.) A. Robyns) em diferentes temperaturasPalavras-chave adicionais: espécies de cerrado; Malvaceae; sementes florestais. AbstractTemperature may affect the germination process mainly that of water absorption and all the biochemical reactions and physiological processes related to the seeds. Eriotecha gracilipes is a tree species of the Malvaceae family found in the Savannah and Atlantic Forest biomes. The objective of this work was to find the adequate temperature for the germination of the seeds and the production of seedlings of that species. Recently harvested seeds were submitted to the constant temperatures of 20, 25, 30, and 35 °C and the alternate temperatures of 20-30 and 25-35 °C with four repetitions of 25 seeds each and photoperiod of 24 h. Having elapsed a period of 30 days, seeds stored in paper bags were submitted to the germination test at the temperatures of 20 and 25 °C. The highest germination percentages were verified at the temperatures of 20, 25, and 20-30 °C when values of, respectively, 67, 70, and 60% were attained. Speed of germination indexes were also the highest (2.6, 2,8, and 2.3) under those temperatures. Primary roots length and dry weight were the highest under temperatures of 20, 25, and 20-30 °C. After a storage period of 30 days, germination was of 96% and the speed of germination index of 6.3.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.