Caracterização biomorfológica, germinação, vigor e armazenamento de sementes de angico-vermelho [Parapiptadenia pterosperma (Benth.) Brenan]

Abstract

This study aimed to characterize morphometrically seeds of Parapiptadenia pterosperma (Benth.) Brenan, establish the best conditions for achieving for testing germination and vigor, study the behavior of seed tolerance to stress and monitor the physiological quality for different storage conditions. Seeds were collected from trees in Poço das Trincheiras, Alagoas. The moisture degree of seeds was determined at 105 °C. We measured length, width, thickness and weight of 1000 seeds. They were submitted to temperatures of 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, 35 °C, 40 °C and 20-30 °C alternating in the presence and absence of light. For morphology to the seeds were dipped for 24 hours in distilled water, for further analysis of their internal structures. In the seminal post, we evaluated the whole process of germination. It was found the effect of different water potentials through osmotic potentials 0,0; -0,3; -0,6; -0,9 and -1,2 MPa, obtaineds with aqueous solutions of NaCl and PEG 6000. To this end, were evaluated, germination, IVG, length of shoot and root dry matter and through polynomial regression. For tetrazolium seeds were submerged for 2, 3 or 6 hours solution of 2, 3, 5 triphenyl tetrazolium chloride at concentrations of 0.075, 0.25, 0.5 or 1%, in chamber at 30 °C, in the dark. We developed a coloring scheme of seeds, observing the presence and location of damage and the physical conditions of embryonic structures. The averages of germination, tetrazolium and accelerated aging were compared by Tukey test at 5% probability. For the accelerated aging, seeds were distributed in gerbox adapted and incubated at 41 °C for 24, 48, 72 and 96 hours. After each period seeds were placed to germinate under ideal conditions. In stressed seeds for 96 hours is also applied the tetrazolium test (0.25%/3h). For analysis of longevity seeds were packed in paper and glass bottles hermetically sealed. They were then stored in the refrigerator, dry chamber and uncontrolled conditions. Being taken at 0, 1, 3, 6 and 9 months to determine moisture content, germination, IVG, seedling length and dry matter. To both, the results were submitted to polynomial regression. Seeds with 8.7% moisture had an average 14.8, 10.6 and 0.85 mm to length, width and thickness respectively. Contains one kilogram approximately 21.274 seeds. The seeds are unalbuminous, the embryo is axial and the cotyledons are invaginados. Germination is epigeous and the seedlings are fanerocotylar. It was observed behavior photoblastic optional neutral and temperature optimum of 30 °C. The seeds subjected to the effects of PEG geminaram to the osmotic potential of -0.6 MPa and those treated with NaCl solutions showed germination at all osmotic potentials studied. Concentration of 0.25% tetrazolium solution for 3 hours was adequate to evaluate the physiological quality and vigor the seeds. Seeds packed in paper or glass can be stored for nine months in environments refrigerator or dry chamber without losing its vigor.