Interactive Effects of Culture System and Carbon Source on Mineral Nutrition, Growth, and Shoot Proliferation in Chestnut Micropropagation

This study investigated the interactive effects of the culture system and carbon source on growth, shoot proliferation, and mineral nutrition dynamics in the in vitro propagation of chestnut. Explants of the ‘Akyüz’ cultivar were used in the Woody Plant Medium. Both plant tissues and culture media were analyzed for Fe, Cu, Mn, Zn, and Mg concentrations. Morphological parameters, nutrient accumulation, and depletion patterns were evaluated. The results demonstrated that the liquid culture system supplemented with sucrose significantly enhanced plant growth, chlorophyll content, callus development, and shoot multiplication. Sucrose treatments promoted higher accumulation of Fe, Cu, Zn, and Mg in plant tissues, whereas glucose treatments resulted in significantly higher Mn accumulation. Correlation and principal component analysis revealed strong positive relationships between growth parameters and Fe, Mg, Cu, and Zn, whereas Mn exhibited significant negative correlations. Among the machine learning models, Support Vector Regression showed the highest predictive performance for plant length (R2 = 0.74) and SPAD (R2 = 0.87). Nutrient depletion analysis showed substantial reductions in mineral concentrations in all treatments after four weeks. Overall, the combination of liquid culture systems with sucrose provides optimal conditions for chestnut micropropagation by promoting favorable nutrient interactions and minimizing antagonistic effects.