Resumo

MARTINEZ, J. M.; RODRIGUEZ-TREJO, D.A.; GUIZAR-NOLAZCO, E.  e  BONILLA-BEAS, R.. Natural and artificial scarification of Lupinus bilineatus Benth. Seeds. Rev. Chapingo ser. cienc. for. ambient [online]. 2008, vol.14, n.2, pp.73-79. ISSN 2007-4018.

The species of Lupinus colonize burned areas and fix N. In other countries, the species of this genus are utilized in forest plantation and agroforestry systems. Their seeds exhibit physical dormancy. In the present study was conducted the seed testing and was studied the germination of Lupinus bilineatus Benth., considering the following factors and levels: scarification (natural: fire, smoke; artificial: immersion in sulfuric acid during 10, 20, 30 and 40 minutes), day/night temperature regime in controlled environment chamber (15/10, 20/15, 25/20, 30/25 °C) and light (with and without light). The experimental design was in ramdom blocks, with the blocks nested into the temperature factor. Was conducted a mixed variance analysis (with the Mixed procedure of SAS) and the Tukey test. The purity was 97.1 %, the weight 66,666.7 seeds·kg^-1, the humidity content (dry weight basis) 7.1 %, and the viability 98 % (tetrazolium test). For the germination was significant (P=0.0101) the interaction among scarification treatment, temperature and light. The maximum germination (82.5 %) was recorded for the seed scarified chemically during 30 or 40 minutes, at 25/20 °C with light. The higher the chemical scarification time the higher the germination. At 20/15 °C with light, the germination after fire scarification (38.5%) was higher than the one for the control (18.5 %). Generally the control showed germinations lower than 30 % in the different treatments, showing different levels of physical dormancy in the studied seed, and the relevance of fire to reduce such dormancy. It was relevant the utility of chemical scarification to stop the dormancy.

Palavras-chave : physical dormancy; chemical scarification; germination; fire.

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