Multidisciplinary approach to in vitro propagation of Coelogyne pandurata Lindl. from Kalimantan: synergistic effects of naphthalene acetic acid and yeast extract with a mathematical biology perspective

Abstract

This study investigates the synergistic effects of Naphthalene Acetic Acid (NAA) and yeast extract on the in vitro propagation of Coelogyne pandurata (black orchid) using a multidisciplinary approach that combines biological experimentation and statistical analysis. The research aimed to optimize vegetative growth, specifically shoot, leaf, and root development, by applying different concentrations of NAA (0, 1, 3, and 5 mg/L) and yeast extract (0, 0.5, 1, and 1.5 g/L). Data analysis involved Pearson correlation, Kruskal-Wallis test, and hierarchical cluster analysis. The Pearson correlation matrix revealed a strong positive relationship between shoot and leaf growth (r = 0.93), indicating that increased shoot formation was associated with leaf development. A weaker correlation was observed between shoot and root growth (r=0.39), and a moderate correlation was found between leaf and root growth (r=0.55). Statistical analysis using the Kruskal-Wallis test showed significant differences in root number (p_value=0.04) among various NAA treatments, with the 1 mg/L NAA concentration resulting in the highest root number. Yeast extract concentration also significantly influenced shoot (p_value=0.03) and root (p_value=0.03) development, while leaf number remained unaffected (p = 0.07). Cluster analysis using Ward’s method revealed distinct treatment groups based on growth patterns. Treatments with moderate yeast extract concentrations (1–1.5 g/L) clustered together, showing enhanced shoot and root growth, while high concentrations of NAA combined with yeast extract resulted in suppressed root development. These findings indicate that a balanced combination of NAA and yeast extract optimizes the vegetative growth of black orchids. This study contributes to the understanding of growth regulation in Coelogyne pandurata and offers insights for improving orchid propagation in vitro.