Optimization of the in vitro embryo culture method for use in sunflower breeding

Sunflower is the most important oil crop, in the selection of which an important and long-term stage is the production of inbred lines. The method of in vitro embryoculture of zygotic embryos can be used to accelerate the alternation of generations during year-round cultivation in phytotron-greenhouse conditions. The methods of culturing sunflower explants are not effective enough and require improvement. The aim of this study was to select and evaluate the optimal parameters for in vitro cultivating immature embryos. The influence of embryo age (10, 15, 20 days after pollination) and hormones (BAP 0.25 mg/l and IAA 1 mg/l or BAP 0.5 mg/l and IAA 2 mg/l) in the nutrient medium on the formation of seedlings was studied. In the variant of the nutrient medium without hormones, the yield of normally developed seedlings increased with an increase in the age of embryos from 10 to 15 and 20 days by 45 and 50%, respectively. Addition of hormones to the nutrient medium increased the yield of seedlings from 15-20 day-old embryos compared to 10-day-old ones by an average of 40%, but deformed additional shoots were formed in the plants. Optimal explants for obtaining plants are immature 15-day-old embryos grown on the Murashige-Skoog nutrient medium without hormones or with a low hormone content. The results of the study can be used in developing a scheme for accelerating the sunflower selection process using the Speed breeding technology.