Resumo

RIVERA, Patricia; VILLASENOR, José Luis  e  TERRAZAS, Teresa. The Asteraceae stomatal complex and its relationship with the atmospheric CO₂ increase in the Reserva Ecológica del Pedregal de San Ángel, Mexico. Rev. Mex. Biodiv. [online]. 2013, vol.84, n.2, pp.499-508. ISSN 2007-8706.  https://doi.org/10.7550/rmb.30933.

The stomatal apparatus of 26 species of Asteraceae inhabiting the Reserva Ecológica del Pedregal de San Ángel, Mexico were characterized and compared under the hypothesis that plants living in the Mexico basin are responding to anthropogenic atmospheric CO₂ increments with stomatal modifications. Leaves of herbarium specimens collected before the 70's were removed, cleared, and studied to compare with leaves of individuals collected in 2009 and 2010 in the same area. The results showed that stomatal density is negatively associated to guard cells length (r_s = -0.73, p < 0.0001) as observed in other taxa. In addition, significant differences (p< 0.05) in the stomatal apparatus of 13 species were detected; both decrease (5 species) and increase (6) in stomatal density with or without reducing or increasing guard cell length. These changes associated with increments of CO₂ follow the trends found in other groups of plants. No modifications were detected in Artemisia ludoviciana, Bidens odorata, and Zinnia peruviana. Stomatal responses to anthropogenic CO₂ increments are highly variable as shown by the results with Asteraceae growing in the Reserva Ecológica del Pedregal de San Ángel.

Palavras-chave : Artemisia ludoviciana; Bidens odorata; Zinnia peruviana; atmospheric pollution; Mexico's basin; stomatal density; cell guard length.

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