Effect of The Application of ZPT IAA (Indole Acetic Acid) and Kinetin on Multiplication of Granola Potato Shoots (Solanum Tuberosum L.) In Vitro

english

Abstract

Seedlings produced through tissue culture with an imbalanced ratio of growth regulators often exhibit poor quality and uneven growth. The success of shoot multiplication in granola potato can be improved by optimizing the ratio of growth regulators, particularly auxins and cytokinins. This study aimed to determine the optimal concentrations of Indole-3-acetic acid (IAA) and kinetin for shoot multiplication of granola potato. The experiment was conducted from June to October 2024 at the Tissue Culture Laboratory of Jember State Polytechnic. A Completely Randomized Factorial Design (RALF) was used, consisting of two factors and three replications. The first factor was IAA concentration, comprising 0.4 mg L⁻¹, 0.7 mg L⁻¹, and 1.0 mg L⁻¹. The second factor was kinetin concentration, consisting of 0.5 mg L⁻¹, 1.0 mg L⁻¹, and 1.5 mg L⁻¹. The results showed a significant interaction between 0.4 mg L⁻¹ IAA and 0.5 mg L⁻¹ kinetin in accelerating callus emergence, with the earliest appearance observed at 6.33 days. This indicates that a balanced ratio of auxin and cytokinin can promote faster callus development. The combination of 0.7 mg L⁻¹ IAA and 1.0 mg L⁻¹ kinetin resulted in the earliest shoot emergence at 5.67 days. This is likely because IAA promotes cell elongation, while kinetin stimulates cell division. Treatment with 1.0 mg L⁻¹ IAA showed a highly significant effect on the number of segments (24.89) and the number of roots (29.22). Meanwhile, treatment with 0.7 mg L⁻¹ IAA significantly increased root length (5.91 cm). These results suggest that IAA plays a vital role in promoting cell elongation and enhancing cell wall plasticity, enabling cells to expand and elongate more effectively.