Seed thermo-priming accelerates the growth of Ceiba glaziovii (Kutze) K.Schum. seedlings

Background: Global climate changes have caused temperature increases that can harm plant development, especially the initial growth and establishment of seedlings for the recovery of degraded areas. However, there are species in which these losses are attenuated when the seeds are thermo-primed to sublethal temperatures. Therefore, the objective of the present study was to evaluate the influence of seed heat conditioning on germination and initial growth of Ceiba glaziovii (Kuntze) K. Schum seedlings, an endemic species occurring in seasonally tropical dry forest in Brazil. Methods: Seeds of C. glaziovii were exposed to 70 oC for 15, 30, 45, 60 and 90 minutes as pre-germination treatments. The control did not undergo heat treatment. Germination variables, vegetative growth, survival rate and normal leaves were evaluated. Results: Thermo-priming negatively affected the germination proportion of C. glaziovii seeds with increasing exposure time. However, it significantly enhanced vegetative growth and seedling survival rate of this species after transplanting, without impairing the formation of normal leaves. Conclusions: Thermo-priming of seeds was found to produce more vigorous seedlings of Ceiba glaziovii.