Changes in the anatomical characters of root and stem of three large-seeded soybean (Glycine max (L.) Merrill) under drought stress

Drought stress, one of the most common abiotic environmental stresses, occurs most often due to climate change, and this can limit plant growth and development. Plant genotypes including soybeans often provide different anatomical responses in the face of drought stress. This study aims to find out the changes in the anatomical characters of root and stem of three large-seeded soybean genotypes under drought stress conditions. The experimental method was used in this study and using polybags as an experimental unit which was carried out at the Greenhouse of the Faculty of Agriculture, Mataram University. The study was conducted using the Completely Randomized Design (CRD) factorial with two factors. The first factor was the drought stress (K) consisted of K0 (normal, no drought stress) and K1 (drought stress). The second factor was the large-seeded soybean genotype (G) consisted of G1 (KH1), G2 (Argomulyo), and G3 (Grobogan). Each combination of the treatments was repeated in three replicates. The results of this study showed that: (1) drought stress increased the thickness of the epidermis and phloem layers and decreased the thickness of the cortex, parenchyma stele, and xylem in the root anatomy, while in the anatomy of the stem decreased in the thickness of the epidermis, the thickness of xylem and phloem, meanwhile in the anatomy of the leaves did not show any difference. (2) Under drought stress conditions, Argomulyo was the lowest in thickness of the cortex and xylem of the roots and stems compared to genotypes KH1 and Grobogan. (3) KH1 experienced a significant increased in the diameter of the stem pith under drought stress.