Electrical conductivity test for evaluating physiological quality in snap bean (Phaseolus vulgaris L.) seeds

Abstract

Snap bean is a variety of common bean (Phaseolus vulgaris L.) that is cultivated and consumed as a vegetable worldwide. In order to optimize the crop's production, germination tests are used to ensure that seeds are high in quality. However, because these tests possess inherent limitations, vigor tests, such as the electrical conductivity test, may be used instead to assess seed quality. The goal of the present study was to develop a standardized methodology for measuring electrical conductivity in snap bean seed that could reliably assess the physiological quality of seed batches. Groups of seeds (n = 50) from each of seven snap bean genotypes (UEL 1, UEL 2, HAV 21, HAV 22, HAV 34, HAV 35, and HAV 42) were immersed in distilled water (75 or 150 mL) for various immersion periods (2, 4, 8, 12, 16, 20, or 24 h), using a completely randomized 7 2 7 factorial design, with eight replicates per treatment. After immersion, the electrical conductivity of seeds from each treatment group was measured in S cm -1 using a conductivity meter. The group means were subjected to ANOVA and the Scott-Knott test (p 0.05). The optimal conditions for the electrical conductivity test in snap bean seeds were a 16-h immersion in 75 mL of water. Under these conditions, genotypes could be clearly differentiated based on their seed vigor, optimizing the measurement of seed quality.