Acta Scientiarum. Agronomy ISSN: 1679-9275 ISSN: 1807-8621 Editora da Universidade Estadual de Maringá - EDUEM Almeida, João Paulo Nobre de; Lessa, Bruno Franca da Trindade; Pinheiro, Charles Lobo; Gomes, Fernanda Melo; Medeiros, Sebastião; Silva, ydianne Cavalcante Germination and development of Amburana cearensis seedlings as influenced by seed weight, light and temperature Acta Scientiarum. Agronomy, vol. 39, no. 4, 2017, October-December, pp. 525-533 Editora da Universidade Estadual de Maringá - EDUEM DOI: https://doi.org/10.4025/actasciagron.v39i4.32786 Available in: https://www.redalyc.org/articulo.oa?id=303055078013 How to cite Complete issue Scientific Information System Redalyc More information about this article Network of Scientific Journals from Latin America and the Caribbean, Spain and Journal's webpage in redalyc.org Portugal Project academic non-profit, developed under the open access initiative Acta Scientiarum http://www.uem.br/acta ISSN printed: 1679-9275 ISSN on-line: 1807-8621 Doi: 10.4025/actasciagron.v39i4.32786 Germination and development of Amburana cearensis seedlings as influenced by seed weight, light and temperature João Paulo Nobre de Almeida1*, Bruno Franca da Trindade Lessa2, Charles Lobo Pinheiro3, Fernanda Melo Gomes3, Sebastião Medeiros Filho3 and Cydianne Cavalcante Silva1 1Universidade Federal Rural do Semi-Árido, Cx. Postal 137, 59625-900, Mossoró, Rio Grande do Norte, Brazil. 2Universidade Federal do Vale do São Francisco, Petrolina, Pernambuco, Brazil. 3Universidade Federal do Ceará, Fortaleza, Ceara, Brazil. *Author for corresponde. E-mail: [email protected] ABSTRACT. The objective of this work was to study the seed germination and seedling growth of A. cearensis (Allemão) A. C. Sm. influenced by seed weight and under different temperature and light conditions. Seeds were individually weighed and divided into three weight classes (light, medium and heavy), and each was subjected to germination tests under two light conditions (presence or absence) and six temperature regimes (20, 25, 30, 35, 40, and 20-30°C). The experiment was established with a completely randomized design in a split-split plot arrangement with four replicates. We determined the first count, final germination percentage and germination speed index. To assess seedling growth, the length and dry mass of the epicotyl and root + hypocotyl axis were also determined. The data were subjected to Tukey’s test (p ≤ 0.05). The optimal conditions for seed germination occurred at a temperature of 30°C, with light and medium seeds showing greater vigour. Temperatures of 35 and 40°C were detrimental to the growth of the species, whereas the best conditions occurred with light and medium seeds at temperatures of 25 and 30°C in the presence of light. Keywords: cumaru, abiotic factors, seed vigour. Germinação e desenvolvimento de plântulas de Amburana cearensis em função do peso da semente, luz e temperatura RESUMO. O objetivo do trabalho foi estudar a germinação de sementes e o crescimento de plântulas de Amburana cearensis (Allemão) A. C. Sm. em função do peso das sementes sob diferentes condições de temperatura e luz. As sementes foram pesadas individualmente e separadas em três classes (leves, médias e pesadas), e cada uma foi submetida a testes de germinação em duas condições de luz (presença e ausência) e seis regimes de temperatura (20, 25, 30, 35, 40 e 20-30°C). O experimento foi inteiramente casualizado em parcela sub- subdividida com quatro repetições. Nós determinamos a primeira contagem, porcentagem final e o índice de velocidade de germinação. Para a avaliação do crescimento das plântulas, o comprimento e a massa seca do epicótilo e do eixo raiz/hipocótilo. As condições ótimas para a germinação das sementes ocorreram na temperatura de 30°C e com um maior vigor com sementes leves e médias. As temperaturas de 35 e 40°C foram prejudiciais ao crescimento da espécie, enquanto as melhores condições ocorreram com as sementes leves e médias nas temperaturas de 25 e 30°C e na presença de luz. Palavras-chave: cumaru, fatores abióticos, vigor de sementes. Introduction large areas (Almeida et al., 2010). However, primary information about A. cearensisis limited and scattered, The predatory extraction suffered by some particularly regarding its propagation and ecology, important plant species native to the Caatinga biome is which makes studies on the germination and seedling putting them at risk of extinction. The survival of establishment of this species necessary to enable Amburana cearensis (Allemão) A. C. Sm., commonly agronomic management including appropriate known in Brazil as ‘cumaru’ or ‘imburana-de-cheiro’, techniques for its proliferation. is threatened, given that the simple removal of its bark (medicinal part) causes great damage to the plant The classification of seeds by weight is a strategy (Canuto, Silveira, Bezerra, Leal, & Viana, 2008). It is that can be used to standardize seedling emergence in necessary to preserve this species as, despite its the field and to obtain seedlings with similar sizes unquestionable economic and social importance, due and/or greater vigour (Carvalho & Nakagawa, 2012). to logging and the wide use of ther parts of the plant in Seed weight is a key variable in the production process, folk medicine, its predatory use continues to decimate as it is directly related to seed quality (Silva, Maia, & Acta Scientiarum. Agronomy Maringá, v. 39, n. 4, p. 525-533, Oct.-Dec., 2017 526 Almeida et al. Moraes, 2007). This is because heavier seeds were Some researchers have studied the temperature better nourished during their development and are and type of light suitable for the seed germination of therefore more vigorous due to well-formed embryos native species such as Licania rigida Benth. (Diniz, and larger amounts of reserves (Carvalho & Nakagawa, Moreira, Silva, & Medeiros Filho, 2008) and 2012). Luetzelburgia auriculata (Nogueira, Silva, Bezerra, & Several studies have been conducted to assess the Medeiros Filho, 2012). Nevertheless, there is a lack influence of seed weight on the germination and of information regarding the direct effects of seed physiological quality of many plant species. reserves and environmental factors on the However, studies are still quite scarce for forest germination process of forest species. species, with some species such Hymenaea Thus, this work aimed at studying the stigonocarpa, Tabebuia heptaphylla, A. cearensis and germination and development of A. Cearensis Enterolobium coontortisiliquum being citedamong them seedlings from different seed weight classes under (Pereira, Giraldelli, Laura, & Souza, 2011; Ribeiro, different temperature and light conditions. Costa, Senna, & Caliman, 2012; Almeida, Pinheiro, Material and methods Lessa, Gomes, & Medeiros Filho, 2014; Lessa, Almeida, Pinheiro, Gomes, & Medeiros Filho, We randomly collected seeds of A. cearensis from 2015). the ripe fruit of 20 adult plants at the Experimental The ecological significance of the relationships Farm Vale do Curu in Pentecoste, Ceará State, 110 among seed weight, light requirements and km from Fortaleza. The harvested fruit were packed temperature fluctuation seems to be related to the in polyethylene bags and sent to the Seed Analysis need to avoid germination in deep soil, where it is Laboratory at the Federal University of Ceará difficult for small seeds to emerge (Thompson & (UFC) in Fortaleza, Ceará State, where the seeds Grime, 1983). In some species, the light were extracted, manually processed and dried under requirement for seed germination is strongly shade conditions for six days. Thereafter, the seeds influenced by the temperature range over which were packed in polyethylene bags and stored at seeds can germinate, which is characteristic of each ±12°C and 50% relative humidity. species (Bewley, Bradford, Hilhorst, & Nonogaki, Four hundred seeds were separated from the 2013). Temperature directly influences the total seed sample and individually weighed using an germination percentage, affecting both the water analytical balance (0.0001 g) to classify the sample absorption rate and biochemical reactions (Amato et into three distinct classes based on their specific al., 2007). According to their response to the weight (Figure 1), defined as light (< 0.25 g), presence of light, seeds can be classified as positively medium (0.25 - 0.35 g) and heavy (> 0.35 g). photoblastic (benefited by light), negatively Thereafter, the seeds from the submitted sample photoblastic (negatively affected by light) ornon- were individually weighed and classified into their photoblastic or indifferent (Marcos Filho, 2015). respective classes. Figure 1. Frequency histogram (A) and box plots (B) for the weight distribution of a sample of 400 Amburana cearensis (Allemão) A.C. Sm. seeds. Acta Scientiarum. Agronomy Maringá, v. 39, n. 4, p. 525-533, Oct.-Dec., 2017 Seed germination in Amburana cearensis 527 The water content and weight of a thousand seeds These data were evaluated by the Shapiro-Wilk and from every class were determined based on the Kolmogorov tests to assess their normality. Analysis of recommendations of the Rules for Seed Analysis variance (ANOVA) and Tukey’s test (5%) were then (Brasil, 2009). Seed sterilization was performed by conducted for the normally distributed data. The Box- immersing all the seeds from every class in 5% sodium Cox transformation was used for the non-normal data, hypochlorite for 15 minutes and a 0.4% nystatin® and the non-parametric Mann-Whitney