ACCELERATED PRODUCTION OF ONE GENERATION OF ALLIUMS PER YEAR BY THE TECHNOLOGY OF FLOWER BUD CULTURE IN VITRO

Abstract

Onion (A. cepa L.) is a perennial herbaceous plant, which may be grown from seed to seed in a two- or three-year culture. Acceleration of the creation of breeding forms of onion is possible by producing of haploid and doubled-haploid plants, as well as of a single generation using regulated phytotron conditions with protected soil. In our research, a collection of onion plants was used. Buds were planted on a nutritional medium. To form calluses, the buds were cultivated in a thermostat at 25°C in the dark. To induce shoot formation after callus formation, a modified nutrient medium was used. Then the seedlings were cultivated on filter bridges in test tubes with a liquid nutrient medium without hormonal supplements at a 5000-8000 lux illumination and a18-h photoperiod. The developed onion plants were planted in pots with a sterile soil mixture, which were covered with perforated plastic cups and placed in a climatic chamber under a 10000-150000 lux illumination. Regenerating plants at the phase of 3-4 real leaves were transplanted into soil for adaptation to a phytotron, and then into a film greenhouse for cultivation according to the generally accepted technology of onion cultivation. Plants of the first year of vegetation were also obtained through seedlings. After the formation of 3-4 real leaves in onion plants, they were planted in a field where a morphological assessment was carried out. In this way it was possible to grow one generation of onion plants in one year (from bud to bud). The times of callus formation and the formation of seedlings and their cultivation on filter bridges was 120 days. Onion plants were grown in a phytotron for 120 days. In a film greenhouse, plants were cultivated for 60 days before the formation of bulbs, and for 30 days for each, bolting and budding and for flowering. The ripening and drying of the seeds took 60 days. The aligning of onion plants, which were obtained using the technology of flower bud culture in vitro, according to the morphological characteristics of their bulbs in the offspring after self-pollination was determined. These plants are the starting material for the selection of onions.