U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
Date of this Version
3-2017
Citation
ANNUAL REPORT OF THE BEAN IMPROVEMENT COOPERATIVE, No. 60, March 2017. Published by USDA.
Abstract
INTRODUCTION Common bean (Phaseolus vulgaris L.) is considered the main legume for human consumption, being an important source of proteins, carbohydrates and minerals. However, most of its farming occurs under drought conditions, with water deficit being one of the main limiting factors for production, which can reduce it by up to 80% (ROSALES et al., 2012). The effects of drought on the common bean depend on the frequency, duration and intensity of the stress and the phenological stage of the crop, which can affect the photosynthetic efficiency, stomatal conductance, transpiration rate and solute accumulation. Quantifying these components related to drought tolerance is extremely important to define strategies for their use in breeding programs. Therefore, the present study aimed to evaluate two common bean genotypes for tolerance to drought through biochemical and physiological characteristics.
MATERIAL AND METHODS The experiment was conducted in greenhouse, at Agronomic Institute of Paraná State, the experimental design was randomized blocks with six replications and two tolerant cultivars were evaluated, IAPAR 81 and BAT 477. The plants were grown in pots with substrate under 80% of the pot capacity until the phenological stage R5, when the drought began in plots subjected to stress, in which was adopted the water treatment of 30% of the pot capacity for 19 days. Liquid photosynthesis, stomatal conductance, transpiration and carboxylation efficiency of the plant were measured in the morning on sunny days, on the last day of stress, using the portable system Photosynthesis LI-6400XT (LI-COR Biosciences, Lincoln, NE, EUA). For the biochemical analyzes (GPX, APX, protein and proline) it was collected, also in the last day of stress, a leaflet of each plant, arranged in bulk and diluted in proportion 1:5 in four different buffer solutions according to the analyzes. Data were submitted to analysis of variance and Tukey test at 5% of probability by the computer program R (http://www.r-project.org) using the ExpDes and MVar.pt packages.
Comments
U.S. government work.