Salinity and Polyethylene‐Glycol (PEG)‐Induced Osmotic Stress Alters the Early Vegetative Shoot and Root Morphology of Sweet Potato Genotypes in Hydroponic Culture

Cultivation of sweet potato ( Ipomoea batatas L.), one of the most economically important tuber crops, is getting vulnerable for drought and saline prone areas. This study aimed to investigate the effects of polyethylene glycol (PEG)‐induced osmotic stress and salinity (NaCl) stress on shoot and root traits of 10 sweet potato (SP) accessions. The 45‐day‐old uniform and vigorous vines were grown hydroponically by following a completely randomized design (CRD). After 21 days of transplanting, the vines were subjected to three treatments—control, 5% PEG, and 10 dSm −1 . PEG‐induced osmotic stress significantly reduced the number of leaves in the first, second, and third nodes, leaf area index, chlorophyll content by 30.8%, 33%, 42.3%, 25.4%, and 6.7%, respectively, and promoted bud death by 2.7 times compared to the control. Under 10 dS m −1 NaCl, root length in the first, second, and third nodes was reduced by 31.1%, 27.5%, and 25.4%, respectively, compared to the control. Root hair diameter was enhanced by 6–8% under both of the treatments, compared to the control. The first principal component (PC1) distinguished the control from the two treatments and the tolerant genotypes (e.g., BAU SP 4, BARI SP 2, BARI SP 12, and BARI SP 17) from the susceptible ones (e.g., BAU SP 5, BAU SP 6, BARI SP 14, and BARI SP 15). This study offers novel insights into the basis of the selection of the stress‐responsive features. Moreover, the understanding of differential responses of genotypes has potential implications for future sweet potato breeding efforts aimed at root dynamics modification.