Some photosynthetic and growth responses of Annona glabra L. seedlings to soil flooding

Acta Botanica Brasilica

Marcelo S. Mielke¹  Elyabe M. Matos¹  Virginia B. Couto¹  Alex-alan F. De Almeida¹  Fábio P. Gomes¹  Pedro Antonio Oliveira Mangabeira¹ 

[1] ,Universidade Estadual de Santa Cruz Departamento de Ciências Biológicas Ilhéus BA ,Brasil

关键词: Annonaceae;    stomatal conductance;    Brazilian Atlantic rainforest;    net photosynthetic rate;    flood tolerance;    Annonaceae;    condutância estomática;    floresta atlântica;    taxa fotossintética líquida;    tolerância ao alagamento;   

DOI  :  10.1590/S0102-33062005000400025

来源: SciELO

【 摘 要 】

An experiment was conducted with the aim to analyze the effects of soil flooding and leaf position on net primary productivity and whole plant carbon balance of Annona glabra L. (Annonaceae) seedlings, a highly flood-tolerant tree, native to the tropical Americas. All seedlings survived a period of 56 days of flooding without symptoms of stress. Flooding induced significant increments in root, stem and whole-plant biomass (P <0.01), and in the root:shoot mass ratio (P <0.05). Measurements of leaf gas exchange were conducted at days four, 11, 18 and 56 after flooding, on the first (L1), fourth (L4) and seventh (L7) fully expanded leaves from the apex of each seedling. The mean values of stomatal conductance to water vapour (g s) and net photosynthetic rate (A) in the control seedlings were around 0.26 mol m-2s-1 and 8.8 µmol m-2s-1, respectively. Significant reductions (P <0.05) in A were observed from L1 to L7 in controls at all four days of measurements. Reductions in A with increasing leaf age also ocurred for flooded plants, but only at days four and 18. Flooding induced significant changes in gs (P <0.05), reaching 65% of controls at day four but 152% of controls at day 56. Based on the results we conclude that the high survival and growth rates of A. glabra seedlings are directly related to the capacity to mantain a high stomatal conductance and net photosynthetic rate under soil flooding.

【 授权许可】

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