Katiane da Rosa Gomes da Silva

Qualidade fisiológica de sementes de caesalpinia pyramidalis tul: durante o armazenamento

The catingueira (Caesalpinia pyramidalis Tul.) is a shrubby species of widespread occurrence in semiarid northeastern and endemic savanna biome. The irregularity and poor distribution of rainfall in the region to undertake seed production, to the point that most fruit has seeds badly formed or non-viable for germination. Thus, this study investigated the behavior of Caesalpinia pyramidalis Tul. seeds put into different packaging and storage ambient. The fruits were collected in Sao Joao do Carriri city - PB and taken to the Seed Analysis Laboratory, Universidade Federal da Paraiba where they were processed and the seeds stored in plastic bottles and glass, and kept under the following conditions: non controlled laboratory (27 ± 3 oC and 64 ± 20% RH), freezer (-18 oC) and dry chamber (19 ± 5 oC and 74 ± 20% RH) for 225 days. Initially and each 45 days the seeds were submitted to determination of moisture content and the following evaluates: germination first and second count, germination speed index, length and seedling dry mass. It was observed that the viability and seed moisture content is maintained in all ambient and packaging studied in this paper, seed germination when analyzed by the first count test is best preserved when its are wrapped in plastic in a dry chamber and freezer ambient until the period of 135 days.

Pré-hidratação e avaliação do potencial fisiológico de sementes de soja

Soybean seeds submitted to rapid hydration may be damaged by imbibitions with the intensity depending on the seed cultivar and initial moisture content. The present study evaluated physiological changes measured by pre-hydration methods to minimize damage by imbibition. Three lots of each soybean cultivar, CD 202 and CD 215, of uniform size, were evaluated for their moisture content, germination, germination first count, accelerated aging, electrical conductivity and seedling emergence in the field. The moisture contents of seeds were adjusted to 7.5, 10.5 and 13.5%. The seeds were pre-hydrated in a saturated atmosphere and moist substrate for four to six hours and then evaluated for electrical conductivity after 24 hours, and also for germination and field seedling emergence. Pre-hydration treatments in a saturated atmosphere and on a moist substrate for four to six hours effectively reduced damage to seeds with a low moisture content, especially for the CD 202 cultivar. However, pre-hydration on a moist substrate for six hours was more efficient for both genotypes, with fewer solutes leached, and confirmed by a lower value observed for the electrical conductivity test. This resulted in an improved performance in germination tests and seedling emergence in the field.

Physiological maturity of fruits and seeds of Poincianella pyramidalis (Tul.) L.P. Queiroz

The Leguminosae family is one of the most representative botanical families of the Caatinga, with 80 endemic species, highlighting the catingueira (Poincianella pyramidalis). The objective of this research work was to study the maturation process of P. pyramidalis seeds based on the physiological maturity. Five harvest of fruits and seeds were carried out, with 15 days interval each, in a period from July to September 2010. The harvests began 75 days after anthesis (d.a.a.) and lasted until 135 d.a.a. Fruits and seeds were subjected to the following assessments: size, moisture content, and dry mass of fruits and seeds; and germination and vigor of seeds (first count of germination, germination speed index, length and dry mass of seedling). Under the environmental conditions of municipality of Soledade, State of Paraiba, Northeast Brazil, the point of physiological maturity of P. pyramidalis seeds occurs at 125 d.a.a., when the maximum accumulation of dry mass is 1.993 g and moisture content is 21%. The ideal point of harvest is between 130 d.a.a and 135 d.a.a., before natural dehiscence, when the moisture content of seeds is between 13.0% and 5.0%.

Potencial fisiológico de sementes de Clitoria fairchildiana R. A. Howard. - Fabaceae submetidas a diferentes regimes de luz e temperatura

Clitoria fairchildiana Howard, a native of the Amazon region is widely used in reforestation programs, planting trees in the streets, public squares, roads and parking lots because of its broad and leafy canopy and its rapid growth. Thus, the objective was to study the influence of light and temperature regimes on germination and vigor of C. fairchildiana seeds. We evaluated the physiological potential of seeds under constant temperatures (25 and 30°C) and alternating (20-30°C) in different light regimes: white, green, far-red, red and darkness. The experimental design was completely randomized in a factorial 3x5, with four replications. The variables analyzed were: germination percentage, first count and germination speed index (GSI), as well as length and dry mass of shoots and primary roots of seedlings. C. fairchildiana seeds germinate in the dark and in all light regimes, regardless of the temperature used and are considered neutral photoblastic. To evaluate the effect of these seeds is recommended temperature of 30°C in the regime of white light, except for the test seedling dry weight, which indicated the green light, far-red or dark.

FENOLOGIA DE Poincianella pyramidalis (TUL.) L. P. QUEIROZ E SUA RELAÇÃO COM A DISTRIBUIÇÃO TEMPORAL DA PRECIPITAÇÃO PLUVIAL NO SEMIÁRIDO BRASILEIRO

A remarkable feature of the Brazilian semi-arid region is its highly irregular distribution of rainfall in space and time, with two marked periods: the rainy season, with erratic precipitation, of highly variable intensity; and the dry season, the critical period of prolonged drought, when the plant species of the Caatinga (desert vegetation found in northeastern Brazil) express their most remarkable trait, the deciduousness. In such conditions, plant species have their dynamics of growth and development in accordance with rainfall events. Thus, the objective of this study was to characterize the phenophases of Poincianella pyramidalis and their relationship with the temporal distribution of rainfall, which takes place in the form of water pulses. For the phenological study, 32 trees were selected, identified and monitored fortnightly on Acude Farm, located in the municipality of Soledade, PB state, Brazil. To quantify the phenological events, Fourniers percent index and the activity index were adopted, recording the presence and absence of the following phenophases: sprouting, appearance of flower buds, flowering (anthesis), fruiting and senescence, whose data were related to the water pulses and inter-pulses. It was found that the sprouting, flower-bud and flowering phenophases in Poincianella pyramidalis happen synchronously with the temporal distribution of rain pulses in its habitat. The intensity and duration of phenophases in the development of Poincianella pyramidalis depend upon the extent and frequency of the water pulses throughout the rainy season. Total leaf senescence in Poincianella pyramidalis occurs when the inter-pulses of rainfall intensify as the dry season progresses, characterizing deciduousness.

Viabilidade e vigor de sementes de Poincianella pyramidalis (Tul.) L. P. Queiroz pelo teste de tetrazólio

A Caatinga apresenta ampla diversidade de especies com potencial de exploracao, dentre as quais esta a catingueira (Poincianella pyramidalis (Tul.) L. P. Queiroz) a qual se destaca pela importância nas atividades madeireira e florestal. O emprego de testes rapidos em programas de controle de qualidade de sementes e ferramenta imprescindivel para avaliacao de sua qualidade fisiologica. Dessa forma, objetivou-se com este trabalho desenvolver procedimentos do teste de tetrazolio para avaliar a viabilidade e vigor de sementes de P. pyramidalis. Foram testados dois procedimentos para o pre-condicionamento das sementes: entre papel toalha umedecido e diretamente em agua. No preparo das sementes foram testadas a escarificacao manual e corte da semente, na regiao oposta ao hilo. Para coloracao, foram utilizadas duas concentracoes da solucao de tetrazolio (0,075% e 0,15%) e tres periodos de coloracao (30; 60 e 90 minutos), sendo as sementes distribuidas em classes de viabilidade e vigor. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 3 x 3 x 2 (anos de colheita x tempos de coloracao x concentracoes do tetrazolio) com quatro repeticoes de 25 sementes. O teste de tetrazolio foi eficiente para avaliar a viabilidade e vigor de sementes de P. pyramidalis. Apos o corte da regiao oposta ao hilo foi realizado o pre-condicionamento diretamente em agua por 24 horas a 25 oC, quando pode-se executar a remocao do tegumento. A coloracao foi obtida com a imersao da semente em solucao de tetrazolio de 0,075%, por 90 minutos, a 41 °C.

Germinação e vigor de sementes de Sapindus saponaria L. submetidas a tratamentos pré-germinativos, temperaturas e substratos

Sapindus saponaria L. is a large tree distributed especially in the Amazon region is of great importance for the reforestation of degraded areas, construction and manufacture of toys. The aim of this study was to test pre-germination treatments to overcome dormancy and to evaluate the effect of temperature and substrate on seed germination of S. saponaria. The experiment was conducted in a protected ambient and the Seed Analysis Laboratory (SAL), Universidade Federal da Paraiba. Two tests were developed, and tested first in the following treatments: seeds immersion in sulfuric acid (H2SO4) for 0, 15, 30, 45 and 60 minutes, analyzing the variables: emergence and emergence speed index, length and dry mass of seedlings. In the second test, was evaluated the effect of temperatures (25, 20-30, 30 and 35°C) and substrates (sand, vermiculite and coconut dust) on the germination and seed vigor. From the results it appears that the immersion of seeds of S. saponaria in sulfuric acid for 60 minutes is sufficient to overcome dormancy accelerating and standardizing the seedling emergency. The best conditions for testing germination using constant temperature of 30°C or alternating 20-30°C in vermiculite or only 30°C combined with the sand.