ANALYSIS OF SOLUBLE CARBOHYDRATES IN RICE PLANTS

Abstract

Oryza Sativa L. is a plant whose fruit, rice, is a typical Brazilian dish, and adapted to the Brazilian cerrado. The rice plant is rich in carbohydrates. In this work it was analyzed the total soluble carbohydrate contents in rice plants of cultivar BRS Primavera submitted or not to water stress and to verify if the plants under water restriction have higher soluble carbohydrate content in the leaves. Dry leaf samples of rice plants of cultivar BRS Primavera were used, with the following identifications (72.3: sample without water stress conditions; 83.1 and 83.3: samples under water stress conditions). Rice plants of cultivar BRS Primavera that were under water stress conditions were found to have 119.87 and 81.36 mg of carbohydrate per gram of dry matter, in samples 83.3 and 83.1, respectively. The plants that were kept under optimal conditions of soil moisture showed 49.45 mg. g -1 of soluble carbohydrates. The starch content of rice leaves was higher in plants maintained under water stress conditions. Samples 83.1 and 83.3 showed 3.62 and 11.12 mg starch per gram of dry matter more than sample 72.3 (without water restriction). The results obtained for starch followed the same behavior as glucose, fructose and sucrose results, indicating that rice plants grown under water stress tend to increase the total soluble carbohydrate content in leaves as a defense response to moisture limiting conditions. in the ground. It was concluded that rice plants maintained under water stress conditions present higher non-structural carbohydrate content in their leaves when compared to plants grown under ideal soil water conditions.

Keywords: starch content, water stress, glucose, fructose, sucrose