1 research outputs found
GERMINATION AND RE-INDUCTION OF DISSECATION TOLERANCE IN SEEDS OF Senna multijuga (RICH.) IRWIN ET BARN
O objetivo deste trabalho foi analisar diferentes m\ue9todos de
supera\ue7\ue3o de dorm\ueancia, condi\ue7\uf5es \uf3timas
de germina\ue7\ue3o, tais como luz, temperatura, e poss\uedvel
reindu\ue7\ue3o da toler\ue2ncia \ue0 desseca\ue7\ue3o em
sementes de Senna multijuga . Foram testados dois m\ue9todos de
supera\ue7\ue3o de dorm\ueancia: imers\ue3o em \ue1gua com
temperatura inicial de 100\ubaC (\ue1gua quente) e imers\ue3o em
\ue1gua com temperatura constante a 100\ubaC por 20 segundos
(\ue1gua fervente), ambos os tratamentos seguidos de repouso fora do
aquecimento por 24 horas. Para o teste de germina\ue7\ue3o, foram
avaliados os regimes t\ue9rmicos 25\ubaC, 30\ubaC (constantes) e
20-30\ub0C (alternados), na presen\ue7a e aus\ueancia de luz.
Para o teste de reindu\ue7\ue3o da toler\ue2ncia \ue0
desseca\ue7\ue3o, foram selecionadas sementes germinadas com 1, 2,
3 e 4 mm de comprimento radicular e submetidas aos tratamentos de
desseca\ue7\ue3o: sem incuba\ue7\ue3o; com incuba\ue7\ue3o
em solu\ue7\ue3o de polietilenoglicol (PEG6000) nas
concentra\ue7\uf5es de -1,4; -1,7 e -2,0MPa; com
incuba\ue7\ue3o em solu\ue7\ue3o de PEG -1,4MPa + ABA nas
concentra\ue7\uf5es de 1, 10 e 100 \u3bcM. O delineamento
inteiramente casualizado (DIC) foi utilizado em todos os experimentos
com 4 repeti\ue7\uf5es de 25 sementes. A supera\ue7\ue3o de
dorm\ueancia utilizando \ue1gua quente proporcionou germinabilidade
superior a 65%. As sementes de Senna multijuga, apesar de n\ue3o
serem fotobl\ue1sticas positivas obrigat\uf3rias, apresentaram
maior porcentagem de germina\ue7\ue3o sob condi\ue7\uf5es de
luz. Foi poss\uedvel observar a retomada do crescimento ap\uf3s a
secagem em sementes germinadas com rad\uedculas de at\ue9 3 mm de
comprimento.The aims of this study were to verify the effects of different tests in
the overcoming dormancy, excellent germination terms, as light and
temperature, and the possibility of re-induction of desiccation
tolerance in Senna multijuga seeds. We evaluated two tests for
overcoming dormancy: immersion in water with an initial temperature of
100\ubaC (hot water) and immersion in water at a constant temperature
at 100\ubaC for 20 seconds (boiling water), both treatments followed
by rest out of the heating for 24 hours. For the germination test, we
evaluated 25\ubaC, 30\ubaC (constant) and 20-30\ubaC (alternate),
in the presence and absence of light. For the reinduction of
desiccation tolerance, we selected seeds germinated with 1, 2, 3 and
4mm of radicle length. We submitted the germinated seeds to the follow
treatments: no incubation, incubation in polyethylene glycol (PEG6000)
at the -1,4, -1,7 and -2,0MPa; incubation in PEG -1,4MPa + ABA at the
concentrations of 1, 10 and 100\u3bcM. The tests followed a completely
randomized design (DIC) using 4 repetitions of 25 seeds. The overcoming
dormancy using hot water provided the best germination (65%). The Senna
multijuga seeds are not photoblastic required, but in light conditions
the germination was higher. We observed the resumption of the radicle
growth in germinated seeds of up to 3mm length