MORPHOMETRIC CHARACTERIZATION OF SEEDS AND PLANTULES AND Anadenanthera macrocarpa (Benth.) Brenan GERMINATION

Abstract

Anadenanthera macrocarpa (Benth.) Brenan \ue9 uma esp\ue9cie arb\uf3rea, pertencente \ue0 fam\uedlia Leguminosae- Mimosoideae, sendo popularmente conhecida como angico-preto. Possui caracter\uedstica dos est\ue1dios iniciais da sucess\ue3o, ocorr\ueancia natural no Brasil, podendo formar agrupamentos quase homog\ueaneos, com grande potencial na recupera\ue7\ue3o de \ue1reas degradadas. O presente trabalho foi conduzido no Centro de Ci\ueancias Agr\ue1rias da Universidade Federal de Alagoas, objetivando a caracteriza\ue7\ue3o f\uedsica e morfol\uf3gica das sementes, descri\ue7\ue3o das diferentes fases do desenvolvimento p\uf3s-seminal, bem como avaliar diferentes condi\ue7\uf5es de temperaturas e substratos para a realiza\ue7\ue3o do teste de germina\ue7\ue3o. As sementes foram extra\ueddas manualmente, em seguida homogeneizadas, onde duas amostras de 50 sementes foram usadas para a determina\ue7\ue3o da umidade inicial. Uma outra amostra, composta por oito repeti\ue7\uf5es de 100 sementes, foi utilizada para a medi\ue7\ue3o biom\ue9trica e n\ufamero de sementes por fruto. Na caracteriza\ue7\ue3o morfol\uf3gica, as sementes foram imersas em \ue1gua destilada para possibilitar os cortes, sendo as estruturas observadas em microsc\uf3pio estereosc\uf3pio. No estudo p\uf3s-seminal, foram observados diariamente os processos de crescimento das pl\ue2ntulas em substrato rolo de papel-filtro e temperatura constante de 30 \ub0C. Para avalia\ue7\ue3o do comportamento germinativo foram testadas as temperatura constantes de 15 \ub0C, 25 \ub0C, 30 \ub0C, 40 \ub0C e alternada de 20-30 \ub0C, em substratos papel e areia, e foi avaliada a porcentagem, \uedndice de velocidade de germina\ue7\ue3o e distribui\ue7\ue3o da frequ\ueancia relativa, sendo os ensaios conduzidos em delineamento inteiramente casualizado, em esquema fatorial 5 x 2 (temperatura x substrato) com quatro repeti\ue7\uf5es de 25 sementes, sendo as m \ue9dias comparadas pelo teste Duncan a 5 % de probabilidade de erro. Os frutos de angico-preto apresentam grande varia\ue7\ue3o no n\ufamero de sementes por fruto. O eixo embrion\ue1rio ocupa parte da regi\ue3o central da semente com posi\ue7\ue3o axial e linear. A germina\ue7\ue3o \ue9 do tipo ep \uedgea e as pl\ue2ntulas s\ue3o fanerocotiledonares. A temperatura constante de 30 \ub0C e o substrato papel-filtro proporcionaram maiores m\ue9dias de porcentagem e velocidade de germina\ue7\ue3o.Anadenanthera macrocarpa (Benth.) Brenan is a tree species belonging to the family Leguminosae- Mimosoideae which is popularly known as mimosa-black. It features characteristics of early successional, natural occurrence in Brazil and can form clusters almost homogeneous, with great potential in the recovery of degraded areas. This study was conducted at the Center for Agricultural Sciences, University Federal of Alagoas state, aiming at the physical and morphological characterization of seeds, describing the various stages of post-seminal development, and to evaluate various conditions of temperature and substrate to perform the test germination. The seeds were manually extracted, then homogenized, where two samples of 50 seeds were used to determine the initial moisture. Another sample, consisting of eight repetitions of 100 seeds was used to measure the biometry and the number of seeds per fruit. The morphological characterization and the seeds were immersed in distilled water to allow the cuts to the observed structure in microscopes. In the post-seminal study, it was observed the daily processes of seedling growth in rolled paper filter and constant temperature of 30 \ub0C. To assess the germination behavior, the constant temperatures of 15 \ub0C, 25 \ub0C, 30 \ub0C, 40 \ub0C and 20-30 \ub0C as well as the paper and the sand substrates were tested and it was evaluated the percentage, the rate of germination, the relative frequency distribution, and the tests conducted in a randomized design in factorial 5 x 2 (x substrate temperature) with four replicates of 25 seeds, and the averages compared by Duncan 5 % probability. The fruits of black angico show great variation in the seed number per fruit. The embryonic axis occupies part of the central region of the seed with axial and linear positions. The germination is epigeal and the seedlings are fanerocotylar. The temperature determines the 30 \ub0C and the filter paper substrate provided higher average percentage and germination rate