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Proposal for germination and water content standards for seeds of some southern Brazilian native tree species

In order to comply with the legislation on seeds and seedlings (Law n° 10.711, as of August 5th, 2003, and Decree n° 5.153, as of July 23rd, 2004), the REDE SEMENTE SUL {Southern Seed Network)} convened a working group to discuss and draft a document in order to collect and analyze research to be presented as a proposal for germination and water content standards for seeds and validity period of germination tests for 27 southern Brazilian native tree species. The data were collected from the records of seed analyses over the past 25 years at the Fundação Estadual de Pesquisa Agropecuária - FEPAGRO and 5-year records at the Fundação Zoobotânica do Rio Grande do Sul - FZB/RS. The confidence criteria for species selection were the germination results of at least 10 batches obtained during the storage period. The germination standard (Sg), i.e., the minimum germination rate required to certify a batch of seeds, was defined based on the average (µ) and the respective standard deviation (SD) by applying the formula: Pg = µ - DP. Different criteria were used to determine the critical values of seed water content (U%), depending on the type of seeds with respect to their desiccation tolerance (orthodox seeds: maximum U% = µ + DP; recalcitrant seeds: minimum U% = µ - DP; intermediate-class seeds: min U% = µ - DP and maximum U% = µ + DP). The historical data survey from files belowed to FEPAGRO and FZB/RS alowed to set proposal for germination standards, moisture content and validity for the germination test, for 27 native forest species originary from the atlantic south region of Brasil.

dormancy overcoming; seed storage; batch reanalysis


Associação Brasileira de Tecnologia de Sementes R. Raja Gabaglia, 1110 , 86060-190 Londrina - PR Brasil, Tel./Fax: (55 43) 3025 5120 - Londrina - PR - Brazil
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