Effect of seed mass on germination and growth in three dominant species in southern Brazilian coastal dunes

Abstract

The effect of seed mass on germination and growth was tested in fresh-seeds of Blutaparon portulacoides, Panicum racemosum, and Spartina ciliata, selected at random in southern Brazilian populations. The seed mass varied within a population of the three species. Both B. portulacoides and P. racemosum showed normal frequency distribution of seed mass, while S. ciliata did not. Significant differences were observed in seed germination between large and small seeds of all species. In all species the capacity of seedling elongation was greater in seedlings of large seeds than those of small ones. Relative growth rate of seedlings of P. racemosum and S. ciliata decreased with time in all seed mass size-classes. On the other hand, the relative growth rate of B. portulacoides seedlings increased during the first 40 days. Seed mass is an important biological factor, affecting seed germination, seedling elongation, and growth of these species, and favoring large seeds, specially in areas of active sand accretion like coastal dunes.Key words: germination, seedling growth, Panicum racemosum, Spartina ciliata, Blutaparon portulacoides. RESUMO Efeito da massa das sementes na germinação e no crescimento em três espécies dominantes das dunas costeiras do sul do BrasilO efeito da massa das sementes sobre a germinação e o crescimento foi testado com sementes de Blutaparon portulacoides, Panicum racemosum e Spartina ciliata coletadas aleatoriamente em populações no sul do Brasil. A massa das sementes variou dentro das populações das três espécies. Ambas, B. portulacoides e P. racemosum, mostraram distribuição normal na freqüência no peso das sementes, enquanto S. ciliata não apresentou distribuição normal. Diferenças significativas foram observadas na germinação das sementes entre sementes grandes e pequenas nas três espécies. A capacidade de alongamento das plântulas das três espécies é maior nas plântulas originadas de sementes grandes do que nas provenientes de sementes pequenas. As taxas de crescimento relativo das plântulas de P. racemosum e S. ciliata diminuíram com o tempo em todas as classes de massa de sementes. Por outro lado, a taxa de crescimento relativo das plântulas de B. portulacoides aumentou ao longo dos primeiros 40 dias. A massa das sementes é um importante fator biológico, porque afeta a germinação, o alongamento das plântulas e o crescimento nas espécies, favorecendo assim as sementes maiores, especialmente em áreas de ativa deposição de areias, como as dunas costeiras.Palavras-chave: germinação, crescimento das plântulas, Panicum racemosum, Spartina ciliata, Blutaparon portulacoides. Braz. J. Biol., 62(3): 427-435, 2002 428 CORDAZZO, C. V.

Caracterización de la morfología de la semilla de Pinus Occidentalis Swartz

“…La masa de la semilla es un factor biológico importante que afecta la germinación, el alargamiento y crecimiento de las plántulas (Cordazzo, 2002). El tamaño también está positivamente relacionado con el tamaño inicial de la planta (Moegenburg, 1996).…”

Intraspecific variation in seed size and light intensity affect seed germination and initial seedling growth of a tropical shrub

“…October-December 2017 community organization (Yanlong et al 2007;Herrera & Laterra 2009;Souza & Fagundes 2014). While smaller seeds generally germinate faster, larger seeds often have a higher germination percentage than small seeds (Cordazzo 2002). Seed size is also directly related to the amount of nutritional reserves that can be allocated to initial seedling development (Yanlong et al 2007;Souza & Fagundes 2014).…”

EFECTO DEL TAMAÑO DE SEMILLA Y LA TEMPERATURA EN LA GERMINACIÓN DE Quercus rugosa Née

“…La masa de la semilla es un factor que afecta la germinación, el alargamiento y el crecimiento de las plántulas (Cordazzo, 2002). El tamaño de la semilla también Greater germination in large seeds has been observed in many species, such as Cecropia obtusifolia Bertol., in which large seeds have exhibited twice the germination of small ones (Tenorio et al, 2008), sunflower, Helianthus annus L. (Krishnaveni and Sivasubramanian, 2001), and Tragopogon pratensis L. ssp.…”

“…Seed mass is a factor affecting germination, elongation and growth of seedlings (Cordazzo, 2002). Seed size is also positively related to initial plant size (Moegenburg, 1996) and to seedling vigor and survival (Leishmann et al, 2000;Hendrix, 1984).…”