The effect of ethyl methanesulfonate (EMS) and environmental factors on soybean traits

Ethyl methanesulfonate (EMS) mutagenesis is a well-established tool used to induce genetic variability in crops such as soybean (Glycine max) for improvement of agronomic traits. This study evaluates the impact of EMS and environmental factors on morphological, physiological, productive, and biochemical traits across to evaluate the improvement of their traits, which are essential for breeding programs. Soybean seeds were treated with three concentrations of EMS (0.1%, 0.2%, and 0.3% v/v) for its mutagenesis. After the first generation (M1) was obtained, seeds of M1 were grown to M2 seeds obtained in three environmentally distinct stations differing in altitude, temperature, humidity, and soil characteristics. Traits evaluated were germination rate, plant height, branch number, flowering period, pod and seed yield, seed biochemical contents (protein, oil, phenolics), and seed protein profiles through SDS-PAGE. Statistical analysis involving ANOVA (one-way and two-way) and correlation tests were conducted for genotype traits with considering of variables (EMS and environmental factors). Seed treatment with EMS (0.1%) induced many plant traits by increasing their measures, and in some cases (0.2)% gave better results. In the second generation, environmental factors affected the studied traits. However, the values differed among plants treated with EMS, such as the increase in germination rate and protein content, and the decrease in the number of leaves, and oil content, in addition to an increase in plant height and total phenolic content in most treatments. The gel electrophoresis results showed the effect of environmental factors (especially temperature), on the other hand main protein fractions typically found in soybean seeds (conglycinin subunits and glycinin subunits) was appeared. The combined effect of EMS mutagenesis and environmental factors is responsible for genetic improvement. Low EMS concentrations favorably affect productivity and seed quality traits, these improvements are heritable, and are further modulated by environment. The study highlights the importance of evaluating for stability of traits across multiple environments, forming the basis for soybean variety breeding, and considering the changes in their characteristics, especially those which promote their economic, nutritional, and medicinal values.