Abstract
The regeneration of plant communities from seed depends, to a large extent, on the capacity of the seed remaining viable in the soil. The viability and germination of artificially buried Psychotria vellosiana seeds in cerrado soil were studied, with the purpose of discovering some physio-ecological aspects of dispersed seeds and evaluating their potential to constitute a soil seed bank. Seed samples were placed in nylon envelopes and buried in the soil of a Cerrado reserve at two different depths and sites. Buried seeds were retrieved periodically and tested for germination along with dry-stored seeds. In general, there was a reduction in seed germination with storage time, both in soil and dry stored conditions, and in some assays exhumed seeds germinated faster than dry stored ones. In general the soil storage favoured seed viability of ungerminated seeds as compared to dry stored ones, with the seeds remaining partially viable after 10 months of storage. The lack of germination of viable seeds suggests that seeds showed true dormancy and/or required an extended time to germinate. It was observed that some seeds had germinated while buried and such in situ germination tended to increase with rainfall. The water availability in the soil might be a limiting factor for successful germination of P. vellosiana in the field, and the seeds may constitute a persistent soil seed bank in the cerrado as dispersed seeds remain viable in the soil until the following period of seed dispersal.
Highlights
The cerrado is the Brazilian savanna vegeta tion and it encompasses a core area in Central Brazil and the peripheral areas distributed throughout north Brazil, northern and south, and extending to Bolívia and Paraguai (Ferri, 1977; Ratter et al, 1997)
Taking into account that natural seed burial is possible in cerrado vegetation (Labouriau et al, 1964), the objective of this work is the viability assessment of artificially buried seeds of Psychotria vellosiana in cerrado soil as compared to dry stored seeds at room conditions, with the main purpose of evaluating whether dispersed seeds can constitute a soil seed bank
Collected Psychotria vellosiana seeds germinated better under white light than in darkness (F = 8.52; p = 0.019), the germinability had been less than 15% after 135 days incubation at 25 °C
Summary
The cerrado is the Brazilian savanna vegeta tion and it encompasses a core area in Central Brazil (most of Mato Grosso, Mato Grosso do Sul and Tocantins; Goiás; western Minas Gerais and Bahia) and the peripheral areas distributed throughout north Brazil, northern and south (small parts of São Paulo and Paraná), and extending to Bolívia and Paraguai (Ferri, 1977; Ratter et al, 1997). Since seedlings are very sensitive to water stress, one supposed that the cerrado climate was a limiting factor for sexual reproduction of cerrado species, favouring vegetative propagation. Labouriau et al (1964) reported seeing seedlings of a number of species in cerrado vegetation in São Paulo, Minas Gerais and Goias. The authors express the need for more research on seed biology of cerrado species to acquire more general ecological propositions in the cerrado vegetation
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
