GALAX SEED GERMINATION AND PROPAGATION UNDER IN VITRO CONDITIONS

Galax (Galax urceolata) leaves are a popular choice for flower arrangement. It also is a slow growing species and current levels of harvesting are threatening the existence of the wild population. To address this trend, a means for successfully expediting the propagation of Galax would increase its availability and allow for protection against overharvesting and possible extinction. The goal of this study was to develop a protocol for in vitro Galax germination and proliferation. Influences of light intensity, culture medium pH, temperature stratification, and seed maturity were studied for their effects on seed germination in vitro. Plant growth regulators (PGR) such as 6-benzylaminopurine (BA), indole-3-butyric acid (IBA), and gibberellic acid (GA₃) were tested for their effects on germination. In addition, BA and IBA were also tested for shoot development. Our data indicated that wild Galax seeds demonstrated 16.7% viability based on the test of tetrazolium staining. Light significantly increased the germination rate. A stratification temperature of 5°C along with increased seed maturity (as determined by seed color) also significantly increased seed germination. The highest germination rate (76%) was observed from dark-colored seeds stored in the refrigerator at 4°C. The PGR treatments of BA and IBA at various ratios inhibited seed germination. GA₃ exhibited a positive effect on seed germination after the cold stratification pretreatment for dark colored seeds. The BA and IBA treatments were not effective for initiating shoots after 20 days of exposure. While an optimal germination protocol has been established, more research is needed to develop a protocol for seedling proliferation and shoot initiation leading to an efficient production system of Galax plants.