Response of Auxins and Cytokinins on Citrus suhuiensis Adventitious Shoot Culture Initiation and Growth

Bacterial and viral diseases are the common problems hampering vast majority of citrus plant which resulted in the decrease of citrus trees development and production yield. While the usage of chemicals to eliminate internal pathogens is harmful to the ecosystem, plant tissue culture is another alternative to develop disease-free plants based on the defined physical and chemical conditions under aseptic environment. This study aimed to initiate Citrus suhuiensis (C. suhuiensis) adventitious shoot culture specifically in response towards different types of plant growth regulators (PGRs). The effect of explants and PGRs were evaluated on the shoot growth within 35 days. C. suhuiensis shoot cultures were induced from three different explants which are leaf, callus and seeds on the solid Murashige and Skoog (MS) medium containing different combinations of PGR which are auxins i.e. 1-naphthylacetic acid (NAA) or indole butyric acid (IBA) at 0.5 mg/L, respectively with cytokinins i.e. 6-benzylaminopurine (BAP) or kinetin (KN) at various concentrations (0.5 - 4.0 mg/L). Based on the results, the earliest shoot emergence from the cotyledon can be observed after 8th day of inoculation for PGRs combination of 0.5 mg/L IBA with 2.0 mg/L, 3.0 mg/L KN and 3.0 mg/L BAP, respectively. Meanwhile, based on the ANOVA analysis (p-value < 0.05), the most significant PGRs combination for the establishment of C. suhuiensis shoot culture is IBA and KN followed by the treatment of NAA and KN. The findings of this study can serve as a basis for future investigation of micropropagation of shoot culture and cultivation of C. suhuiensis plant.