Abstract:
Persian violet (Exacum affine Balf. f. ex Regel) is a beautiful flowering plant with economic value. Plant conservation and breeding are fundamental to bioindustrial crop production. In this research, synthetic seed and synthetic fruit production technologies were used to assist in the storage of germplasm in vitro for the conservation of Persian violet. Microshoot of 2-3 mm in size was encapsulated with calcium alginate to produce single- or double-layered synthetic seeds and using an innovation called synthetic fruit to encapsulate up to 5 explants. Later, when the synthetic seed and synthetic fruit were stored at 4 and 25 degrees Celsius and then cultured on MS basal medium for 4 weeks, it was found that the synthetic seed and synthetic fruit could be stored for up to 30 days. The germination percentage and germination rate index, and the viability percentage of single-layered synthetic seed and synthetic fruit were more significant than double encapsulated synthetic seed over the entire storage period.
In addition, single or repeated UV-C exposures were also used in conjunction with tissue culture technology to induced in vitro root and mutation for Persian violet breeding. It was revealed that single irradiation of low-intensity UV-C (30 microwatts per square centimeter) which applied to microshoot (2-3 mm in length) for 4 hours before being cultured on MS basal medium for 4 weeks could initiate maximum number and root length without the use of plant growth regulator. Meanwhile, single or repeated UV-C exposure resulted in 44 different types of Persian violet flower mutation. In a single exposure to high-intensity UV-C (234 microwatts per square centimeter) for 6 hours, up to 9 petals were induced. However, a single low-intensity UVC exposure did not affect the morphological characters of the Persian violet flowers. Subsequently, the mutation stability of the Persian violet flower after subculture in vitro was investigated. It was noticed that the 5-petal standard form and the 5-petal flower with separated petals could be transmitted during 3 times subculture.