DROUGHT TOLERANCE OF MAIZE PLANTS OBTAINED FROM THE CELL-LINES RESISTANT TO OSMOTIC-STRESS PRODUCED BY POLYETHYLENE-GLYCOL

The feasibility of the method of cell selection for breeding drought-resistant cultivars of maize (Zea mays L.) was investigated. Resistant cell lines were selected from the callus tissue obtained from the immature embryos of the hybrids Chinese 31 x Tuxpeno Norteno and Chinese 31 x Cateto Sulino Grosso using a medium containing 25% polyethylene glycol. Water-holding capacity and heat resistance were estimated in the leaves of the seed progenies (R1) obtained by the self-pollination of eight regenerants. The cell selection provided plants with enhanced heat tolerance expressed during vegetative growth and tasseling under conditions of insufficient and optimal watering. The maximum increase in the water-holding capacity in the R1 families under study was observed during anthesis. In contrast to the initial maize genotypes, drought did not impede flowering in the selected forms. The expression of drought resistance in the seed progeny of regenerated plants indicates that there is a genetical control over this trait.