Valderez Pontes Matos

Efeito de temperaturas e substratos na germinação de sementes de Myracrodruon urundeuva Fr. All. (Anacardiaceae)

Myracrodruon urundeuva Fr. All. (Anacardiaceae) is a native tree specie with excellent physical, chemical and biological properties. However, due to predatory exploration, it is in the official list of Brazilian species threatened with extinction. This work aimed at studying the germination of M. urundeuva seeds in different conditions of substrate and temperature regime. The experiment was a completely randomized design in a 8 x 7 factorial arrangement (7 temperatures 25, 27, 30, 35, 20-27, 20-30 and 20-35oC; and 8 substrates - sowing in and on: blotting paper, sand, vermiculite and coconut fiber) with four replications with 25 seeds. The following parameters were analyzed: germination (%), first germination count (%), germination speed index, average time of germination (days), and length (cm) of hipocotyl and primary root. Constant temperatures gave the shortest average time of seed germination and favored hipocotyl development. The best results for germination were obtained at 25 and 27oC in all substrates, except for sowing in between blotting paper at 27oC. The vermiculite and coconut fiber substrates allowed satisfactory germinative performance and did not require daily remoisten, proving to be suitable for the evaluation of the physiological quality of M. urundeuva seeds.

Escarificação mecânica em sementes de chichá (Sterculia foetida L.)

Forest species with hard seeds often pose considerable problems to nursery managers because their hard and water impermeable seed coats hinder and delay germination. Therefore, this work aimed to determine the most efficient, practical and low cost methodology to overcome dormancy in chicha seeds. The seeds were submitted to five treatments: mechanical scarification with sandpaper number 40 for three minutes on both sides of the seed without soaking; mechanical scarification with sandpaper number 40 for three minutes in both sides of the seed with 24-hour soaking; mechanical scarification with sandpaper number 40 for three minutes on one side of the seed without soaking; mechanical scarification with sandpaper number 40 for three minutes on one side of the seed with soaking and control treatment whose seeds had not been scarified (intact seeds). The characteristics evaluated were first count and total germination percentages, emergence speed index and shoot and root dry mass The results allowed to recommend mechanical scarification with sandpaper number 40 on one side of the seed for three minutes followed by soaking in water for 24 hours and mechanical scarification in both sides without soaking to overcome dormancy in chicha seeds.

Germination and vigor of Dimorphandra mollis benth. seeds under different temperatures and substrates

The Dimorphandra mollis Benth. - Caesalpiniaceae is a native forest species coming from the Cerrado and Caatinga due to its economical and ecological use, which justifies the studies on seed germination. In this work, germinative performance of D. mollis seeds were studied in different conditions of temperature regime and substrate. The experimental delineation used was completely randomized in factorial 4 x 4 (4 substrates -sand, coconut fiber, vermiculite and paper towel; and 4 temperatures: 25, 30, 35 and 20-30oC), with four replications of 25 seeds each. The following parameters were evaluated: seed moisture content, final germination, first germination count, germination speed index, length and dry matter weight. The best germination and vigor is obtained at 30 and 35oC. The substrates paper towel and vermiculite allow satisfactory germinative performance of seeds, being suitable to evaluate the physiological quality of D. mollis seeds.

Qualidade fisiológica de sementes de araçazeiro durante o armazenamento

O presente trabalho teve como objetivo avaliar diferentes ambientes de armazenamento e embalagens quanto a eficiencia na manutencao da qualidade das sementes de aracazeiro (Psidium guineenseSwartz) durante 180 dias. As sementes foram provenientes de frutos recem-colhidos completamente maduros e de oito acessos do banco ativo de germoplasma do aracazeiro localizado na Estacao Experimental de Itapirema, da Empresa Pernambucana de Pesquisa Agropecuaria - IPA, Goiana, PE, assim denominados: IPA 4, IPA 6, IPA 7, IPA 9, IPA 10, IPA 11, IPA 15 e IPA 16. O experimento foi representado pelas combinacoes dos fatores: sementes de oito acessos do aracazeiro, acondicionadas nas embalagens saco de papel Kraft e vidro, armazenadas nos ambientes normal de laboratorio e no freezer, em Recife, PE, durante 180 dias. A qualidade fisiologica das sementes foi avaliada no inicio e a cada 60 dias de armazenamento, atraves de germinacao e vigor (primeira contagem e indice de velocidade de germinacao) determinando-se tambem o teor de agua das sementes. Os resultados permitiram concluir-se que as sementes dos acessos do aracazeiro tiveram sua qualidade fisiologica reduzida, com perdas significativas na germinacao e vigor, no decorrer do armazenamento. A embalagem de vidro proporcionou maior eficiencia na conservacao da qualidade fisiologica das sementes, sob condicao de alta umidade relativa no interior do freezer, condicao esta que provocou maior deterioracao das sementes acondicionadas em embalagens de papel Kraft. Dentre os ambientes de armazenamento estudados, o mais adequado para conservacao das sementes de aracazeiro foi o ambiente normal de laboratorio, para ambas as embalagens testadas. Os acessos IPA 4 e IPA 6 apresentaram os maiores indices de germinacao e vigor.

Physiological quality of surinam cherry seeds submitted to different procedures of drying and substrates - Part 1.

The present work had as its objective to determine the ideal procedure of drying and the substrate to evaluate the viability and vigour of surinam cherry seeds (Eugenia uniflora L.). The experiment was developed in a completely randomized design in factorial scheme 2 x 4 (2 procedures of drying: shade and sun; 4 substrates: sand, vermiculite, coconut fiber and paper towels) with four replications of 25 seeds each. The water absortion curve was characterized and the following parameters were analyzed: germination percentage, first germination count (%), germination speed index and dead seeds (%). The experiment was conducted in a BOD germinator regulated at constant temperature of 25 oC and regime of continuous light. In the conditions where the work was carried out, the drying under shade and vermiculite may be recommended to evaluate the vigour because they provided the best germination and initial development of surinam cherry seedlings.

Caracterização morfológica de frutos, sementes e germinação de Sideroxylon obtusifolium (Roem. e Schult.) Penn. (Sapotaceae)

RESUMO – Estudos que visam ao conhecimento da morfologia de sementes e plântulas contribuem para a identificacao das especies, facilitando o reconhecimento das fases iniciais do seu desenvolvimento. Assim, os objetivos deste trabalho foram caracterizar morfologicamente as estruturas externa e interna dos frutos e das sementes de Sideroxylon obtusifolium (Roem. e Schult.) Penn., alem de descrever e ilustrar a morfologia externa da plântula. Para a descricao dos frutos foram observados detalhes externos e internos do pericarpo, referentes a textura, consistencia, cor, pilosidade, brilho, forma, numero de sementes por fruto e deiscencia. Foram analisadas as seguintes variaveis externas das sementes: dimensoes, cor, textura, consistencia, forma e posicao do hilo e da micropila; e as internas: presenca ou ausencia de endosperma, tipo, forma, cor, posicao dos cotiledones, eixo-hipocotilo-radicula e plumula. A germinacao foi considerada desde o intumescimento da semente ate a emissao dos protofilos, sendo a plântula considerada estabelecida quando os protofilos ja estavam totalmente expandidos. Os frutos de S. obtusifolium sao dos tipos bacoide, globoso ou elipsoide, indeiscente e monospermico. As sementes variam de globosas a elipsoides, e o embriao e do tipo cotiledonar e ocupa posicao basal na semente. A germinacao tem inicio no decimo segundo dia e pode ser encerrada no vigesimo primeiro dia apos a semeadura. Palavras-chave: Especie florestal, Morfologia, Plântula e analise de sementes MORPHOLOGICAL CHARACTERIZATION OF FRUITS, SEEDS AND GERMINATION OF Sideroxylon obtusifolium (Roem. E Schult.) Penn. (SAPOTACEAE)

Germinação de sementes de Platypodium elegans Vog. submetidas a diferentes tratamentos prégerminativos e substratos

The aim of this work was to evaluate the influence of germinative pretreatments (control; chloridric acid, for 3 min; longitudinal cuts without and with water soaking) and substrates (sand and coconut fiber) in the germination of Platypodium elegans Vog. seeds. The analyzed characteristics were: percentage of germination, first germination count, germination speed index, length and dry mass gain to seedlings. There was no significant difference for the germination percentage (x = 51%), but the longitudinal cuts promoted higher indices of germination speed (x = 0.95) and first germination count (x = 42%). The coconut fiber and the longitudinal cuts induced greater length (x = 13.5 cm) and dry mass gain (x = 50.0 mg) in the seedlings.

Morphology of fruits, seeds and seedlings of Erythrina velutina willd., leguminoseae - Papilionideae

The knowledge about the morphological aspects of both seeds and seedlings has several applications, such as in taxonomy, interpretation of the germination tests under laboratory conditions, in nurseries, as well as in ecological studies. Therefore, the goals of this work were to describe and illustrated both internal and external morphologies of the fruits and seeds as well as the germination phases and seedling development of mulungu (Erythrina velutina Willd.). The fruits and seeds were collected in the soil, which were dispersed by trees distributed throughout different forest fragments in the district of Areia in the State of Paraiba, Brazil. One hundred units were randomly selected for the morphological description of the fruits, seeds and germination phases. The results showed that the seed was reniform; had axial embryo with pulpous cotyledons; epigeal phanerocotylar and showed the presence of heterophylly at the seedlings phases. The described and illustrated aspects were homogeneous and reliable for the identification of the species. Thus, the results are useful in the technological work for evaluation of the physiological quality of the seeds as well as for evaluation of seedling morphology during germination tests. In addition, the results are useful for identification of the species in nurseries and in natural regeneration studies.

Efeito do tipo de embalagem e do ambiente de armazenamento sobre a germinação e o vigor das sementes de Apeiba tibourbou AUBL.

This work had as objective of evaluating the effect of different packings and different storage environments in the maintenance of the germination and the vigor of Apeiba tibourbou seeds. The seeds were conditioned in the folowing packings: transparent glass containers, the Kraft paper bags and transparent polyethylene bags stored under following environments: environmental conditions of laboratory, in the freezer and in chamber. In the beginning and at every 45 days of storage was determined the seed moisture content and carried out germination and vigor tests. The results showed that the seeds present the largest germination and vigor when conditioned in Kraft paper bags and polyethylene bags, under environments conditions of laboratory.

Métodos para superação da dormência de sementes de quixabeira ( Sideroxylon obtusifolium (Roem. & Schult.) T.D.Penn.).

Due to absence of information about the methodology for the evaluation of the physiological quality of seeds of medicinal arboreal species seeds, the aim of the present work was to determine the most efficient method to overcome the seed coat dormancy in seeds of Sideroxylon obtusifolium (Roem.& Schult.) T.D.Penn. Besides the intact seeds, the ones which had not been submitted to any treatment, the following pre-germinating methods were used: chemical scarification: the seeds were immersed in pure sulfuric acid for 10, 20, 30, 40, 50 and 60 minutes at the environment temperature (27oC ± 1oC); mechanical scarification: the seeds were rubbed manually in sandpaper number 50, in the opposite side of micropyle, without and with soaking for 24 or 48 hours; thermal scarification: immersion in water at 100oC for 15 or 30 seconds; immersion in water to 80oC until cooling. The effects of treatments were evaluated through tests of germination and vigor. There were significant differences among the treatments for all the evaluated parameters (percentage and speed of germination, length and dry weight of shoot and root), and the most evident cause of dormancy was the coat impermeability, which efficiency was overcame by the immersion of seeds in pure sulfuric acid for 30 minutes.