Cattleya labiata Lindl. is a high-value ornamental orchid whose growth and development are highly dependent on adequate water availability. Drought stress disrupts cellular water balance, reduces photosynthetic activity, and restricts plant growth. Under in vitro conditions, drought stress can be simulated by incorporating mannitol into the culture medium as an osmotic agent. This study evaluated the effects of different mannitol concentrations on the morphological, physiological, and anatomical responses of C. labiata plantlets cultured in vitro. The experiment was arranged in a Completely Randomized Design (CRD) with five mannitol concentrations (0, 50, 100, 150, and 200 mM), each with five replications. The evaluated parameters included plantlet survival, morphological characteristics (root length, plantlet height, and leaf number), chlorophyll content, and stomatal density. Quantitative data were analyzed using analysis of variance (ANOVA), followed by Tukey’s Honestly Significant Difference (HSD) test at the 5% significance level. Mannitol concentrations ranging from 50 to 200 mM did not significantly affect plantlet survival, morphological growth, or chlorophyll content. In contrast, stomatal density decreased significantly with increasing mannitol concentration, indicating that anatomical responses were more sensitive to osmotic stress than morphological and physiological traits during the three-week culture period. These findings demonstrate that mannitol effectively induced drought stress responses in C. labiata plantlets under in vitro conditions, although the applied concentrations were insufficient to produce significant morphological and physiological alterations within the experimental period.
G. Pratiwi, Endang Nurcahyani, W. Sri et al.· World Journal of Advanced Re...· 0 citations
Phalaenopsis amabilis (L.) Blume is an ornamental orchid with high aesthetic and economic value and is recognized as the national flower of Indonesia. However, its growth and physiological performance are highly susceptible to drought stress. This study aimed to evaluate the effects of mannitol-induced drought stress on the growth of P. amabilis plantlets under in vitro conditions and to determine the highest mannitol concentration that could be tolerated. Mannitol was applied as an osmotic agent at five concentrations (0, 50, 100, 150, and 200 mM) in Vacin and Went (VW) medium using a completely randomized design with five replications. The evaluated parameters included plantlet survival percentage, morphological characteristics, chlorophyll content, and stomatal density. Data were analyzed using analysis of variance (ANOVA) at the 5% significance level, followed by Tukey's test when significant differences were detected. The results showed that all treatments maintained a 100% plantlet survival rate throughout the four-week culture period. Mannitol application had no significant effect on morphological characteristics or chlorophyll content. In contrast, stomatal density was significantly reduced with increasing mannitol concentrations. Plantlets cultured on medium containing 50 mM mannitol exhibited the greatest tolerance and maintained normal growth, whereas concentrations of 150–200 mM induced more pronounced drought stress responses. These findings indicate that 50 mM mannitol is the optimum concentration for simulating mild drought stress while maintaining the growth of P. amabilis plantlets under in vitro conditions.
Sari Junita Putri, Endang Nurcahyani, W. Sri et al.· International Journal of Sci...· 0 citations
Potato (Solanum tuberosum L. cv. Cipanas) is a high-yielding cultivar; however, its cultivation is often limited by salinity stress in marginal lands, which adversely affects plant growth and development. This study aimed to evaluate the effects of different NaCl concentrations on the growth and physiological responses of in vitro-grown potato plantlets and to determine the maximum salinity level that could be tolerated. The experiment consisted of five NaCl concentrations (0, 0.25, 0.50, 0.75, and 1.00%) arranged in a completely randomized design. Quantitative data were analyzed using one-way analysis of variance (ANOVA), followed by Tukey's honestly significant difference (HSD) test at the 5% significance level. Increasing NaCl concentrations significantly reduced plantlet height, leaf number, and stomatal index, and induced progressive changes in plantlet color from green to yellowish-green and brownish-green. Potato plantlets remained tolerant to NaCl concentrations of 0.25% based on plantlet height and leaf number, whereas tolerance up to 0.50% was observed for plantlet color and stomatal index, with no significant differences compared with the control. These findings indicate that S. tuberosum L. cv. Cipanas exhibits moderate tolerance to NaCl-induced salinity under in vitro conditions.
Afrilia Nurjannah, Endang Nurcahyani, Enur Azizah et al.· GSC Biological and Pharmaceu...· 0 citations