João Correia de Araújo Neto

Efeito da temperatura e da luz na germinação de sementes de Acacia polyphylla DC.

Acacia polyphylla (Leguminosae-Mimosoideae) is a typical tree species of secondary succession in Brazil, important for restoration of degraded areas. The purpose of this work was to evaluate the seed germination under different temperatures and light conditions. Constant (15, 20, 25 and 30 oC) and alternating (20-30 oC) temperatures were evaluated, at an eight hours photoperiod under white light. Constant temperature of 25 oC was optimal and the light experiments were conducted at that temperature. Seeds were incubated in darkness and at photoperiods from 1 to 12 hours under white light (high red/far-red ratio), as well as at photoperiods under white light initiated and concluded with shade light (low red/far-red ratio). Germination percentage was not affected by the photoperiods under white light tested, but a photoperiod similar or higher than four hours was required for better initial seedling growth. Both germination percentage and speed was not affected by light of a low red/far-red ratio, but they decreased in darkness.

Temperaturas cardeais e efeito da luz na germinação de sementes de mutamba

Guazuma ulmifolia Lam., conhecida como mutamba, e uma especie arborea caracteristica dos estadios iniciais da sucessao secundaria, com ampla ocorrencia natural no Brasil. Possui grande potencial para recuperacao ambiental de areas degradadas. Neste trabalho, conduziram-se dois experimentos, nos quais as sementes foram extraidas e escarificadas antes da instalacao dos testes de germinacao. O primeiro experimento foi desenvolvido com sementes colhidas em outubro de 1995 e teve por objetivo definir as temperaturas cardeais para a germinacao das sementes. Foram testadas as temperaturas de 10, 15, 20, 25, 30, 35, 40 e 45 oC, sob fotoperiodo de oito horas. Os resultados mostraram que a temperatura minima e proxima de 10 oC, a maxima se situa entre 35 e 40 oC e as temperaturas de 25 e 30 oC encontram-se dentro da faixa otima. No segundo experimento, visou-se avaliar o requerimento fotoblastico de sementes recem-colhidas (colheita de outubro de 1996) e armazenadas em câmara seca por um ano (colheita de outubro de 1995). Os testes de germinacao foram conduzidos a 30 oC e as sementes recem-colhidas tiveram a germinacao promovida pelas luzes branca e vermelha, mas inibida pela luz vermelha-extrema e ausencia de luz. As sementes armazenadas, entretanto, revelaram-se insensiveis a luz.

Armazenamento e requerimento fotoblástico de sementes de Acacia polyphylla DC

Acacia polyphylla (Mimosaceae) is a native tree species in Brazil, important for restoration of degraded areas. Seeds of this species were stored under both natural and artificial conditions, to evaluate the seed longevity in soil, conserve the seed physiological quality for two years and verify the photoblastic requirement of stored seeds. Under natural conditions, seeds were buried in light gap and under both thin and closed canopies. Under these conditions, fast deterioration was found and seeds were unable to compose the soil seed bank. Under artificial conditions, seeds were packaged in different containers and stored at both room temperature and in a cold chamber for two years. Periodically, seeds were incubated at 25oC in darkness and under an eight hours photoperiod of both white light (high red-far red ratio) and shade light (low red-far red ratio). During the storage period, germination in darkness was lower than under either white or shade lights. Physiological quality was maintained for two years when seeds were packaged in an impermeable container and stored in a cold chamber. Germinative behaviour of the seeds stored for two years was compared with that of the fresh seeds, at both constant and alternating temperatures, and no effect of either seed age or temperature regime on the photoblastic requirement of the seeds was detected.

Caracterização morfométrica de frutos e sementes e efeito da temperatura na germinacão de Parkia pendula (Willd.) Benth. ex Walp.

Parkia pendula (Willd.) Benth. ex Walp. is a tree species, characteristic of the initial phases of succession, of natural occurrence in Brazil. It belongs to the Mimosaceae family, with great potential in the recovery of degraded areas. The present work aims to characterize fruits and seeds morphometrically as well to identify the best temperature for use in germination test. The fruit is a type of legume, dehiscent, polispermic, with 16 seeds, approximately, per unit. The seeds present ellipsoidal format, axial embryo, with 10,1 mm of length, 4,9 mm of width and 3,1 mm of thickness. The temperatures of 25oC and 30oC provided them larger germinability, while the temperature of 15oC and above 35oC influenced these characteristics negatively.

Caracterização morfométrica de sementes e plântulas e germinação de Anadenanthera macrocarpa (Benth.) Brenan

Anadenanthera macrocarpa (Benth.) Brenan is a tree species belonging to the family LeguminosaeMimosoideae 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

CARACTERIZAÇÃO MORFOMÉTRICA, GERMINAÇÃO E CONSERVAÇÃO DE SEMENTES DE Triplaris brasiliana CHAM. (POLYGONACEAE)

The objective of this study was to characterize morphometrically seeds, evaluate the treatments of scarification, and germination temperatures and the potential seed storage Triplaris Brasiliana Cham., a pioneer species, with great potential for recovery of degraded areas, permanent preservation, riparian areas and land. For the morphometric characterization, it was determined the length and thickness, mass of 1000 seeds, color, shape and hilum and micropyle location, such embryos, the location and type of germination. The germination test was evaluated from seeds with and without scarification at different temperatures. The storage was tested in glass and paper packaging and in refrigerator, dry chamber and ambient conditions. The embryo is axial, and the embryonic axis in the central part of the seed of the lower half, the germination is epigeal and the seedlings are fanerocotylar. Sowing the seeds scarified on paper subjected to 30 °C were more favorable for germination and development of Triplaris brasiliana seedlings, and seeds sensitive to dehydration (intermediate), while preserving physiological quality for longer when stored in the refrigerator and camera in the packages used.

Production and performance of sugarcane seeds (caryopses) from different hybridizations involving RB92579

A major challenge in sugarcane breeding program is the obtaining of enough number of seeds (caryopses) for the development of new improved cultivars. Genotypes differ in their function as pollen recipient and pollen donor, which also affect the seed performance. Thus, the aim of this study was to verify the production and performance of sugarcane seeds from different hybridizations involving RB92579 as pollen recipient and pollen donor. Twelve bi-parental crossings were carried out involving RB92579 and other different genotypes randomly chosen. Seed production potential was evaluated by percentage of fertile spikelets and caryopsis fresh weight. The seed physiological potential was determined by evaluating germination and vigor (index of germination rate, number of normal seedlings per gram of fuzz, and seedling dry weight). The results showed better performance for RB92579 as pollen donor for all characteristics studied. Therefore, RB92579 sugarcane cultivar should be used as pollen donor during hybridizations, condition that permits a greater production and physiological performance of seeds for the sugarcane breeding programs.

MORFOMETRIA E GERMINAÇÃO DE SEMENTES DE Aechmea costantinii (Mez) L. B. Sm. (BROMELIACEAE)

The potential economic and environmental benefits brought by bromeliads production are significant. It is noteworthy that the high degree of degradation of some ecosystems as the Atlantic forest involve reduction of these species. This factor has been worsened by the elevated degree of endemism of these plants, e.g. Aechmea costantinii (Mez) L. B. Sm., which is a high ornamental potential bromeliad but understudied. Thus, the present research aimed to characterize physical and morphological features of A. costantinii fruit and seeds, describing the different stages of post-seminal development, as well as evaluating seed germination behavior with respect to temperature and light. For this purpose, we used fruit and seeds freshly harvested from an Atlantic Forest fragment, located in the city of Maceió, Alagoas State, Brazil. Tests were carried out under a completely randomized design, in a 6x4 factorial scheme (temperature x light) with four replications of 25 seeds. The polyspermic fruit are of tricarpellate/triloculate type and originated from inferior ovary, containing an average of 73 elliptical and mucilaginous seeds with basal embryo. The germination is epigeal-type and occurs in a great intensity and high speed at 35 °C, regardless light presence or quality.

ACÚMULO E DISTRIBUIÇÃO DE MACRONUTRIENTES EM DOIS HÍBRIDOS DUPLOS DE MILHO, EM FUNÇÃO DA DISPONIBILIDADE DE ÁGUA NO SOLO DUPLOS DE MILHO, EM FUNÇÃO DA DISPONIBILIDADE DE ÁGUA NO SOLO

The large-scale production of Baculovirus to control fall armyworm, Spodoptera frugiperda, presents many limitations. The most important limiting factor is that the baculovirus, which infects fall armyworm, causes liquefaction of the integument immediately after death. This disruption of the integument difficultates the large scale production because dead insect must be frozen before being harvested. This fact implies in high lab work need, increasing the cost of the biopesticide. This problem was overcome by the discovery of a new baculovirus nucleopolyhedrovirus (NPV) isolate in Cascavel/PR, that doesn’t cause liquefaction of the integument (isolate 6NR) immediately after the insect death. This is an extremely important factor in a large-scale baculovirus production. In addition, mortality caused by isolate 6NR on 6-day-old-larvae was above 93% (SEM=0.7%), the average weight dead larva was 116.21 mg (SEM=22.9), the larval equivalent and weight equivalent/ha were 15.04 g (SEM=1.2) and 140.32 larvae (SEM=20.1), respectively.

Post harvest of pink ginger floral stems treated with silver thiosulphate, sucrose, and calcium.

O mercado brasileiro de flores tropicais encontra-se em franco crescimento, com uma importante participacao da regiao Nordeste, destacando-se o estado de Alagoas. Dentre as flores tropicais de corte para exportacao, a alpinia (Alpiniapurpurata (Vieill) K. Schum) ocupa posicao de destaque. Visando retardar a senescencia das hastes florais de alpinia, cultivar Pink Ginger, foram conduzidos dois experimentos em laboratorio no CCA da Universidade Federal de Alagoas. No primeiro, foram testados tres tempos (30; 60 e 120 minutos) de exposicao ao tiossulfato de prata 1 mM, seguido ou nao de pulsing em sacarose a 20%, por 12 horas. No segundo experimento foram verificados os efeitos nas relacoes hidricas e longevidade das hastes da adicao de sulfato de calcio a 50 e 100 mM, silicato de sodio a 1,25 e 2,50 mM, alem da interacao sulfato de calcio a 50 mM + silicato de sodio a 1,25 mM, em solucao de manutencao. Nos dois experimentos, a testemunha consistiu da manutencao das hastes em agua destilada. A massa fresca e a qualidade das hastes foram determinadas a cada dois dias. O tiossulfato de prata, aplicado na forma de pulsing por 60 minutos ou mais, promoveu desidratacao das hastes. O uso de sulfato de calcio promoveu aumento da durabilidade comercial e melhoria da hidratacao das hastes.