<![CDATA[Abstract. Nurcahyani E, Qudus HI, Melta AA, Amini NA. 2026. Protein banding pattern and RAPD marker analysis of local Lampung cassava (Manihot esculenta) under PEG-induced drought stress. Biodiversitas 27 (7): d270715. https://doi.org/10.13057/biodiv/d270715. Drought stress is one of the major environmental constraints limiting cassava (Manihot esculenta) productivity in Indonesia. Under controlled greenhouse conditions, Poly-Ethylene Glycol (PEG 6000) is widely used to simulate water-deficit stress by reducing water availability without causing direct toxicity to plant tissues. This study evaluated the physiological and molecular responses of local Lampung cassava to different levels of PEG-induced drought stress by integrating physiological measurements with protein banding patterns and Random Amplified Polymorphic DNA (RAPD) analyses. The experiment was arranged in a completely randomized design with five PEG 6000 concentrations (0%, 10%, 20%, 30%, and 40%). Physiological responses were assessed through total soluble carbohydrate, chlorophyll, and reducing sugar contents, whereas molecular responses were evaluated using SDS-PAGE protein banding pattern analysis and RAPD markers. Increasing PEG concentration significantly increased total soluble carbohydrate and reducing sugar contents, but reduced chlorophyll content. SDS-PAGE analysis revealed the appearance of a distinct protein band at approximately 34 kDa with 40% PEG treatment, accompanied by increased intensity of a ~50 kDa protein band at higher PEG concentrations. RAPD amplification using primer OPB-20 consistently detected a distinct DNA fragment of approximately 1,100 bp in PEG-treated plants but not in the control. These coordinated physiological and molecular responses indicate that PEG-induced drought stress triggers stress-associated biochemical and genomic changes in cassava. The identified protein and RAPD banding patterns represent preliminary candidate molecular indicators of drought responsiveness and provide a useful basis for future validation and early screening of drought-tolerant cassava genotypes.]]>
