Epicuticular waxes from caatinga and cerrado species and their efficiency against water loss

Anais da Academia Brasileira de Ciências

Antonio F. M. Oliveira¹  Sérgio T. Meirelles¹  Antonio Salatino¹ 

[1] ,Universidade de São Paulo Instituto de Biociências São Paulo SP ,Brasil

关键词: caatinga;    cerrado;    epicuticular waxes;    n-alkanes;    triterpenoids;    water diffusion;    caatinga;    cerrado;    ceras epicuticulares;    n-alcanos;    triterpenóides;    evaporação;   

DOI  :  10.1590/S0001-37652003000400003

来源: SciELO

【 摘 要 】

The effects of the contents and chemical composition of the foliar epicuticular waxes of species from the caatinga (Aspidosperma pyrifolium, Capparis yco, Maytenus rigida and Ziziphus joazeiro) and cerrado (Aristolochia esperanzae, Didymopanax vinosum, Strychnos pseudoquina and Tocoyena formosa) were evaluated as to the resistance to water loss by means of an experimental device constructed for this purpose. In general, the waxes of the caatinga species investigated were more efficient against water loss than cerrado species. Increase of the thickness of the waxy deposits from 40 to 90m g.cm-2 had no significant effect on the resistance to water loss. The chemistry of the wax constituents was shown to be an important factor to determine the degree of resistance to evaporation. n-Alkanes and alcoholic triterpenes were the most efficient barriers, while hentriacontan-16-one (a ketone) and ursolic acid (an acid triterpene) revealed lowefficiency. The higher efficiency of the waxes of the leaves from caatinga species (mainly those of C. yco and Z. joazeiro) is probably accounted for the predominance of n-alkanes in their composition. The lower efficiency of the waxes of A. pyrifolium (caatinga), T. formosa and A. esperanzae (both species from the cerrado) is probably a consequence of the predominance of triterpenoids in the waxes of the two former species and hentriacontan-16-one in the latter.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License