Performance of soybean plants in response to seed size and stressful and non-stressful environments

Abstract

The size of soybean seeds can influence the germination process and seedling growth. Therefore, this study aimed to evaluate the size of soybean seeds during germination and seedling growth under non-stressful conditions and salt and water stress. The design used was completely randomized, arranged in a 2 × 3 × 3 factorial scheme, with two soybean cultivars [BMX Extra IPRO (74i78RSF IPRO) and BMX Desafio RR (8473 RSF)], three seed size classes (5.75; 6.5 and 6.5 mm) and three osmotic stress treatments [control (non-stressful conditions), salt or water stress]. In the control treatment, distilled water was used, and water and salt stresses were used PEG and NaCl solutions with osmotic pressure of –0.3 MPa, respectively. First germination count, germination, radicle length, seedling length, shoot dry matter, and root dry matter were measured. Under non-stressful or stressful environments, soybean seed size does not affect germination rate and seedling growth for the cultivar BMX Extra IPRO. For the BMX Desafio RR cultivar, the larger seeds are more adapted to the saline stress condition. Regardless of seed size and soybean cultivar, water stress reduced germination and seedling growth rate.