Application of Biotechnology for Sunflower Inbred Line Development: Immature Embryo Rescue

Immature embryos rescued in sunflower breeding programs represent one of the important procedures for creating a competitive research program. The development of inbred lines in a short period offers a significant advantage, enabling faster adaptation of sunflower hybrids to farmers’ needs, including new herbicide technologies, such as existing sulfonylurea- and imidazoline-based treatments or the introgression of new disease-resistant genes. In our research, we initiated immature embryo rescue by harvesting at 168 h, 216 h, 264 h, and 312 h after fecundations. The media used were based on MS (Murashige and Skoog) and supplemented with different concentrations of BAP, NAA, and GA3. For the experiments, three types of genotypes were used: inbred lines, populations, and sunflower hybrids. Our results demonstrated a significant connection between harvest timing, the medium used, and the genotype. The highest survival rates were recorded as up to 81% for hybrids and 71% for inbred lines. For immature embryo rescue, they were obtained at 312 h on MS5—2.0:0.4:0.4 (BAP:NAA:GA3). The genotype, culture medium composition, and harvesting time are essential factors for optimizing the in vitro rescue technique of immature sunflower embryos. The survival rates of immature embryos were significantly influenced by the interaction of these factors.