Givanildo Zildo 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.

Morphoanatomy of Myracrodruon urundeuva Fr. All. seedlings submitted to different levels of water in the soil

Myracrodruon urundeuva Fr. All. is a medicinal plant of the Caatinga biome, in brazilian northeast. This region is characterized by prolonged dry periods but little is known about the plants mechanisms to tolerate low water availability during their initial phase of growth and establishment seedling. The objective of this project was to evaluate morphological and anatomic characteristics of M. urundeuva seedlings submitted to different water levels in the soil. In a first experiment, the diaspores were sown in trays containing soil taken from the place of occurrence of the species. The substratum was moistened with water to reach 10 to 60% of the soil water retention capacity, with 5% intervals. In a second experiment, the diaspores were sown in the substratum kept at 60% of its water retention capacity for 15 days for the total seedling emergence since this is the most favorable condition for the species as identified during the first phase of this experiment. After that period, plant watering was suspended and the seedling kept in substrata at 60, 30, 25, 20, 15, and 10% of their water holding capacity for an additional period of 10 days, both experiments performed in protected environment. The increasing reduction in water availability led to a reduction in the number of leaves, the leaf area and leaflet thickness, the number of stomata in the leaf and in the cotyledon, the root length and the diameter of the central root. Characteristics such as the stem length, length, width and thickness of the cotyledon were not modified by the

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.