[Production of potato breeding material using somatic hybrids between Solanum tuberosum L. dihaploids and the wild diploid species Solanum bulbocastanum Dunal. from Mexico].

An original approach to overcome interspecific incompatibility when backcrossing the tetraploid Solanum tuberosum + S. bulbocastanum somatic hybrids with cultivated potato was realized. This method is based on the decrease in their ploidy using anther culture and involvement of the haploid producer S. phureja IvP35. The feasibility of obtaining a diploid progeny from the somatic hybrids carrying genetic material of the wild species S. bulbocastanum and crossable with S. tuberosum dihaploids was demonstrated.

[Diploid hybrids between allotetraploid wild potato species Solanum acaule Bitt., S. stoloniferum Schltdl. and dihaploids of S. tuberosum L].

The possibility to obtain diploid hybrids by pollination of allotetraploid wild potato species Solanum acaule and S. stoloniferum plants with fertile pollen of S. tuberosum dihaploids was demonstrated for the first time. Dihaploid hybrids have arisen with comparatively high frequency (from 12.5 to 33.3%). They were characterized by high regularity of meiosis and high fertility. They easily crossed with S. tuberosum dihaploids, forming viable progeny. This seems prospective for effective introgression of valuable genetic gene pool of wild allotetraploid potato species in breeding material of S. tuberosum on the diploid level.

[Application of somatic hybrids between dihaploids of potato Solanum tuberosum L. and wild diploid species from Mexico in breeding: generation and backcrossing of dihaploids of somatic hybrids].

The efficiency of an original approach to involvement of the valuable genetic pool of wild diploid potato species from Mexico is estimated. The essence of this method is in generation of dihaploids (2n = 2x = 24) of tetraploid somatic hybrids (2n = 4x = 48) followed by backcrossing with dihaploids of Solanum tuberosum. A haploid producer, S. phureja IvP35, was used to generate ten dihaploids of S. tuberosum + S. pinnatisectum, all of which crossed with fertile S. tuberosum dihaploids and developed plump viable seeds. This gives the possibility of an efficient introgression of the genes valuable for breeding from wild species to the bred plants at a diploid level, which has several advantages compared with the corresponding procedure at a tetraploid level. A part of the dihaploids produced was compatible (the pollen tubes reached the ovary) with diploid and tetraploid forms of S. pinnatisectum; however, no viable seeds were developed. The attempt to generate the dihaploids of S. tuberosum + S. bulbocastanum somatic hydrides using the haploid producer S. phureja IvP35 was unsuccessful.

[Immunoelectrophoretic study of serum proteins of swine embryos]. / Immunoélektroforeticheskoe issledovanie belkov syvorotki krovi plodov svinei

During embryonic development, antigenic spectrum of serum proteins from porcine foetuses gradually become more complex, the number of antigens increasing from 4 in 1-month embryos to 12--13 in mature foetuses. Immunoelectrophoretic analysis of the serum reveals prealbumin, alpha- and beta-globulins. It was shown that with respect to its immunological properties, procine fetuin is not presented by a true stage-specific protein, since together with ESA-glogulin it contains antigens which are identical to those in the blood serum of adult animals. Immunoelectrophoresis did not reveal gamma-globulins in embryonic serum. It is suggested that porcine foetuses may synthesize the main proteins of the blood serum; however, final formation of antigenic spectrum is accomplished in postembryonic period.