GERMINATION OF SEEDS OF Chorisia glaziovii O. Kuntze SUBMITTED TO WATER STRESS AT DIFFERENT TEMPERATURES

Abstract

Chorisia glaziovii O. Kuntze, da fam\uedlia Bombacaceae \ue9 uma florestal nativa do Nordeste brasileiro, conhecida popularmente como barriguda devido ao tronco bojudo, seus frutos s\ue3o deiscentes e as sementes revestidas por uma estrutura fibrosa (l\ue3) utilizada nas ind\ufastrias de estofados. Por isso objetivou-se avaliar o comportamento germinativo e o vigor das sementes de Chorisia glaziovii, submetidas ao estresse h\ueddrico em diferentes temperaturas. Os tratamentos consistiram dos potenciais de -0,1; -0,2 e -0,3 MPa simulados com polietileno glicol (PEG 6000), al\ue9m do n\uedvel zero (0,0) utilizando apenas \ue1gua destilada, nas temperaturas constantes de 20, 25 e 30\ub0C, em delineamento experimental inteiramente ao acaso. As vari\ue1veis analisadas foram: porcentagem, primeira contagem e \uedndice de velocidade de germina\ue7\ue3o de sementes, al\ue9m do comprimento de ra\uedzes e altura de parte a\ue9rea, e massa seca de ra\uedzes e parte a\ue9rea das pl\ue2ntulas. As maiores porcentagens de germina\ue7\ue3o das sementes de Chorisia glaziovii foram obtidas na aus\ueancia de estresse h\ueddrico independentemente da temperatura, sendo a de 20\ub0C prejudicial \ue0 germina\ue7\ue3o das sementes, com redu\ue7\ue3o para 20% no potencial de -0,1MPa; nas temperaturas mais elevadas, as sementes foram mais tolerantes ao estresse h\ueddrico, com uma porcentagem de 68% neste mesmo potencial. As sementes de Chorisia glaziovii s\ue3o sens\uedveis ao estresse h\ueddrico, com germina\ue7\ue3o totalmente inibida em todas as temperaturas no potencial de -0,3 MPa.Chorisia glaziovii O. Kuntze, the Bombacaceae family is a native forest of northeastern Brazil, popularly known as paunchy, due to bulging trunk. Its fruits are dehiscent and its seeds covered with a fibrous structure (wool) used in upholstery industries. Therefore, it was aimed to evaluate the germination behavior and seed germination of Chorisia glaziovii, subjected to water stress at different temperatures. The treatments consisted of the potential of -0.1; -0.2 And -0.3 MPa simulated with polyethylene glycol (PEG 6000) plus zero (0,0) level using only distilled water, at constant temperatures of 20, 25 and 30 \ub0C in a totally randomized experimental design chance. The analyzed variables were: percentage, first count and rate of germination rate of seeds, plus the length of roots and shoots of height, and dry weight of roots and shoots of seedlings. The highest percentage of germination of Chorisia glaziovii were obtained in the absence of water stress independent of temperature, so the 20 \ub0C detrimental to seed germination, reducing to 20% in potential -0.1MPa; at higher temperatures the seeds were more tolerant to water stress, with a percentageof 68% at this same potential. The seeds of Chorisia glaziovii are sensitive to water stress, with completely inhibited germination at all temperatures in the potential of -0.3 MPa