Spore germination of eight homosporous ferns in a temperature gradient
Por:
Juárez-Orozco S., Orozco-Segovia A., Mendoza-Ruiz A., Pérez-García B.
Publicada:
1 jul 2013
Categoría:
Plant Science
Resumen:
Temperature determines the germination percentage and germination rate
of non-dormant fern spores and is known to be a crucial factor for
breaking or inducing dormancy in seeds. The objective of this study was
to determine the effect of optimal, supraoptimal and suboptimal
temperatures on spore germination of eight species of terrestrial
homosporous ferns. Spores were incubated for one month in a temperature
gradient from 15 to 35 degrees C in either light or dark. Thereafter,
the spores were transferred to 25 degrees C and incubated in the light.
The optimal temperature for germination varied among species, and
germination inhibition and possible secondary dormancy were induced at
both suboptimal and supraoptimal temperatures. At 35 or 30 degrees C,
with light, spores of most species did not germinate or exhibited low
germination percentages, owing to thermoinhibition or possible
thermodormancy. In the dark, the spores did not germinate at any of the
temperatures tested. After the spores were transferred to the light at
25 degrees C, a high percentage of spore germination was observed.
Incubation in the dark at different temperatures also promoted high
germination or dormancy. Temperatures that promoted germination might be
related to the season that the different species germinate rather than
their habitat, as a number of species within the same habitat had
different optimum temperature requirements. Differences in temperature
requirements may help to form a soil spore bank. It is necessary to
determine whether secondary dormancy was induced by supraoptimal and
suboptimal temperatures to further understand spore germination and
colonisation in the field. (C) 2013 SAAB. Published by Elsevier B.V. All
rights reserved.
Filiaciones:
Juárez-Orozco S.:
Univ Nacl Autonoma Mexico, Fac Ciencias, Dept Ecol & Recursos Nat, Lab Proc & Interacc Ecol, Mexico City 04510, DF, Mexico
Orozco-Segovia A.:
Univ Nacl Autonoma Mexico, Dept Ecol Func, Inst Ecol, Mexico City 04510, DF, Mexico
Mendoza-Ruiz A.:
Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biología, San Rafael Atlixco 186, C.P. 09340 México, D.F., Mexico
Pérez-García B.:
Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biología, San Rafael Atlixco 186, C.P. 09340 México, D.F., Mexico
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