GERMINATION AND MORPHOLOGY OF SEEDS AND SEEDLINGS OF Parkia gigantocarpa FABACEAE: MIMOSOIDEAE

Jonathan Wesley Ferreira Ribeiro,Adriana Paula D'Agostini Contreiras Rodrigues,Eliazel Vieira Rondon,Ademir Kleber Morbeck De Oliveira

doi:10.5380/rf.v45i2.34504

Abstract

AbstractParkia 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.

Highlights

Due to high deforestation that took place in the last decades, especially in ecosystem with great biodiversity like tropical forests (LAURANCE, 1999; RODRIGUES et al, 2009), many studies arose aiming to increase knowledge of native forest species and production of their seedlings, to be used in ecological restoration programs (SANCHEZ-CORONADO et al, 2007); BRANCALION et al, 2011).Diversity of available seedlings in native forest species nurseries is generally insufficient, because of the difficulty to obtain seedlings or even for lack of knowledge on physiology and germination technology (VIANI; RODRIGUES, 2007)
Morphological aspects of seeds External and internal morphological characteristics of seeds were observed with a stereomicroscope (Stemi DRC, Carl Zeiss)
Remembering that some morphological characters are different from the ones reported for other species of the same family, morphological characters of seeds and seedlings of P. gigantocarpa can be used to identify the species in field

Summary

Introduction

Due to high deforestation that took place in the last decades, especially in ecosystem with great biodiversity like tropical forests (LAURANCE, 1999; RODRIGUES et al, 2009), many studies arose aiming to increase knowledge of native forest species and production of their seedlings, to be used in ecological restoration programs (SANCHEZ-CORONADO et al, 2007); BRANCALION et al, 2011). Diversity of available seedlings in native forest species nurseries is generally insufficient, because of the difficulty to obtain seedlings or even for lack of knowledge on physiology and germination technology (VIANI; RODRIGUES, 2007). Besides plantation of native species plantlets coming from nurseries, another alternative is recuperation of plantlets or transposition of seed banks and plantlets. F. et al ISSN eletrônico 1982-4688 / ISSN impresso 0015-3826

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