N赤veis cr赤ticos dos 芍cidos ac谷tico, propiˋnico e but赤rico para estudos de toxicidade em arroz em soluˋˋo nutritiva

作者:Kopp; Mauricio Marini; Luz; Viviane Kopp da; Coimbra; Jefferson Luiz Meirelles; Sousa; Rogerio Oliveira de; Carvalho; Fernando Iraja Felix de; Oliveira; Antonio Costa de
来源:Acta Botanica Brasilica, 2007.
DOI:10.1590/S0102-33062007000100014

摘要

the occurrence of anaerobic conditions in hydromorphic soils, associated with the presence of organic matter favors the development of anaerobic microorganisms that produce phytotoxic substances, especially short chain organic acids. selection of promising rice genotypes for use under these conditions requires difficult field evaluations, which may be simplified with the use of hydroponic culture. the aim of this work was to determine the range of concentration and the dependent variables most appropriate to selecting rice genotypes for tolerance to organic acids in hydroponic culture. six concentrations of the three main acids formed in the soil: acetic acid (0; 4; 8; 12; 16 and 20 mm), propionic acid (0; 3; 6; 9; 12; and 15 mm) and butyric acid (0; 2; 4; 6; 8 and 10 mm) and two genotypes of high divergence (brs-7-taim and saiban) were used. the results indicate that the most appropriate concentration ranges for studies of rice tolerance to organic acids are: 8.4 and 15.8; 4.2 and 9.1 and 3.7 and 7.7 mm for acetic, propionic and butyric acids, respectively, and the most responsive variable was root length.

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