Vigor of seeds and biochemical activity in rice seedlings treated with organic acids

Abstract

Vegetal residues in anaerobic decomposition in irrigated farmings of rice produce organic acids, such as, acetic, propionic, butiric, formic, vanilic, which affect the establishment of seedlings. Therefore the present work had for objective to analyze the physiological quality of seeds and bioquimical activity of rice BR IRGA-409 seedlings, treated with several concen- trations (zero; 1; 2; 4; 8 and 16 ml/L) of acetic and propionic acids. In order to performer this some assay were conducted such as: tests of vigor (first count, electrical conductivity, emergency speed index and emergency), chemical composition (starch, total soluble sugars and protein contents), determinations of the activity of α-amylase and fosfatase acid, and measurements of growth (chlorophyll concentration and leaf area). The regression analysis showed that the germination, emergency speed index, the emer- gency of seedlings and the electric conductivity were significantly affected with the increase in the concentrations of acid. Starch, total soluble sugars and protein contents were reduced on higher concentrations (≥8 ml/L) for both acids. The total activity of α-amylase was more enhanced by acetic acid than propionic acid, while the activity of phosfatase-acid was not modified. The chlorophyll contents and leaf area decreased with increment on concentrations of acetic and propionic acids.