Teste de germinação e conservação de sementes de Thespesia populnea (L.) Soland. ex Correa

Abstract

This work aimed to study the physiological seed Thespesia populnea (L.) Soland. ex Correa., depending on the treatments of dormancy, temperature, light quality, moisture content, storage conditions, as well as to monitoring and to recording the different stages after germination. Seeds from several trees located in the city of Maceió, in the period from September to October 2011 were used. The treatments to break seeds dormancy were: mechanical scarification, chemical scarification with sulfuric acid, soaking in hot water (80 º C) until the cooling, soaking in distilled water at room ytemperature for 24 hours and intact seeds (control). Elapsed this step, the seeds were incubated at temperatures of 10ºC, 15ºC, 20ºC, 25ºC, 30ºC, 35°C and 40°C and alternating temperatures of 20-30ºC under white light. Regarding the post-seminal development, several processes triggered during growth, development and differentiation of seedlings were evaluated. The drying curve was determined by adjusting the regression curve, relating the behavior of the moisture content of the seeds and germination. We defined the best light conditions for conducting germination and vigor tests. Therefore, the quality of light: red, far-red and dark at constant temperatures of 20 °C and 30°C and alternating 20-30°C under white light. To evaluate the physiological potential of the seeds, were tested two containers (paper type "Kraft" and glass bottles) and three storage environments (normal, dry chamber and refrigerator). Samples were taken each other month from each storage condition for determination of moisture content, percentage and speed of germination, electric conductivity, length of shoot / root ratio and dry matter. All assays were set up in a completely randomized design with four replications of 25 seeds per treatment. For purposes of statistical analysis, the percentage of germination data was transformed to arcsin √p/100. According to the results, it was observed that the seeds are preferred photoblastic with epigeal germination, and present higher percentage and speed of germination when scarified mechanically. A temperature of 30 °C was considered the optimum temperature for germination. The seeds are sensitive to moisture loss and can be stored with moisture content of 11% for a period of up to eight months, regardless of packaging and storage conditions.