INTRA-AND INTER-POPULATION VARIATION IN SEED SIZE AND DORMANCY IN <i>Schizolobium parahyba</i> (Vell.) Blake IN THE ATLANTIC FOREST

Abstract

Seed size and dormancy level were studied in 20 trees from two populations of Schizolobium parahybato evaluate how these characteristics occurbetween and within populations, and whether seed germination was affected by its morphometry. These two populations are located in the coastal (Paraty) or mountain (Miguel Pereira) regions in the state of Rio de Janeiro, Brazil. The seed morphometrictraits (length, width, thickness and weight) were measured. Germination with or without seedcoatdormancy treatment (mechanical scarification) wasassessedbya randomized emergence test in nursey. All morphometric traits differed significantly among individuals and between populations. The trees from the mountain region showed a larger seed size and a lower dormancy level than that of trees from the coastal region. Seed size had no effect on seed germination or seedling development. Climate influence on the determination of germination behavior is discussed based on the results. Keywords: forest seed; population diversity; seed morphometrictraits; germination. RESUMOO tamanho da semente e seu grau de dormência foram estudados em 20 matrizes de duas populações de Schizolobium parahyba, visando avaliar como estas características se distribuem entre e dentro de populações e qual a influência da morfometria na capacidade de germinação da espécie. As populações são procedentes da região litorânea (Paraty) e montanhosa (Miguel Pereira) no Estado do Rio de Janeiro. As características morfométricas (comprimento, largura, espessura e massa) foram medidas e a germinação com e sem tratamento de quebra de dormência (escarificação mecânica) foi avaliada em um teste de emergência com delineamento inteiramente casualizado. Todas as variáveis morfométricas diferiram significativamente entre indivíduos e entre populações. As matrizes da região montanhosa apresentaram maior tamanho da semente e um menor nível de dormência do que aquelas localizadas na região litorânea. O tamanho da semente não influenciou a germinação das sementes e o desenvolvimento das plântulas. A influência do clima na seleção do comportamento germinativo da espécie foi discutido com base nos resultados obtidos. Palavras-chave: semente florestal; diversidade populacional; morfometria da semente; germinação.

Weight is a key factor in the physiological quality of Parapiptadenia rigida seeds

“…Generally, a large seed has greater reserve, which can be used by seedling in the early stages of growth (Baskin & Baskin, 2014). However, germination and seedling growth of species such as T. grandis (Khera et al, 2004) and S. parahyba (Freire et al, 2015) were not affected by seed size. In the present study, it was evident that higher means of cumulative emergence and emergence velocity index were associated with the physiological quality afforded by seed weight.…”

“…In general, high weight seeds exhibit higher germination capacity when compared to low weight seeds when exposed to low stress conditions (Genna & Pérez, 2016). For some forest species, it has been shown that germination and vigor of seedlings are related to seed weight (or size) (Du & Huang, 2008;Owoh et al, 2011;Socolowski et al, 2011a;Landergott et al, 2012;Kuniyal et al, 2013), but other species show no influence (Khera et al, 2004;Freire et al, 2015).…”

“…Studies conducted with Gmelina arborea (Owoh et al, 2011), Tecoma stans (Socolowski et al, 2011b), Pterocarpus marsupium (Mishra et al, 2014), Sapindus mukorossi (Attri et al, 2015) and Tamarindus indica (Ghaffaripour et al, 2017) showed a direct relationship between seed weight or size and seedling vigor. However this should not be considered as a rule, as germination and seedlings growth of Tectona grandis (Khera et al, 2004) and Schizolobium parahyba (Freire et al, 2015) were not affected by seed size.…”

Morphological integration between seeds and seedlings ofHymenaea courbaril

“…Both populations presented a weak association between the variables ( Figure 4). Other studies, with another species from Fabaceae, also did not find associations between seed weight and seedling vigor [5], [46]. Seedling survivor and faster germinations associated with seed weight were also not observed [4].…”

Biometria e Potencial Germinativo em Sementes de Peltophorum dubium (Sprengel) Taubert – Fabaceae

“…Segundo Freire et al (2015), mesmo dentro de populações de uma mesma espécie, o tamanho médio das sementes pode variar dependendo das perturbações do meio e do estágio da sucessão vegetal.…”