Induction of embryogenesis in wheat ( Triticum aestivum L.) cultivated microspores

Wheat (Triticum aestivum L.) haploids and doubled haploids are widely used in breeding, the investigations of a combinative variability and its stabilization in homozygotes. In four domestic varieties of winter wheats (Moskovskaya 56, Moskovskaya 39, Galina, Nemchinovskaya 24) and three domestic varieties of spring wheats (Ester, MIS, Amir), with spring wheat variety Falat as a control, the efficacy of embryogenesis in isolated microspores was tested using standard protocol for induction of direct embyo formation in the isolated microspore culture. In all winter varieties there was shown a low frequency of cytoplasmic strands which are typical for the embryogenic microspores, whereas in the spring varieties it was high. After 4 days cultivation in the medium used for induction, the microspore viability decreased in winter varieties, and another 10 days later the viable cells were not observed. The spring varieties developed the multicellular structures which could produce embryoids. The reference variety Falat produced 28 % of pro-embryoids, able mostly to further embryoid formation. Basing on these results, the protocol for inducing direct embryogenesis in wheat microspores was modified, including maltose concentration in medium, the conditions of spikelets heat treatment, the number of ovaries and time when they were added to the culture, the combination and concentration of hormones in the media for induction and cultivation.