The article highlights results of research over simulative apomixes in pear and its utilization for obtaining haploids and homozygote diploids. It has been established that over 50% pear varieties with failed remote hybridization are capable of generating seeds of apomictic origin producing diploid plants. Genotypes displaying maximal inclination to apomixes have been singled out. Apomictic pear seedlings obtained from foreign pollination within the limits of the same combination are inherent in profound morphological diversity. Fruit-bearing apomicts originated from one and the same maternal plant differ to the same extent as hybrid seedlings of the same family. Genetic markers have enabled to establish that these are embryo sacs in which meiosis has completed that give rise to apomictic seeds. In vitro method as used for the purpose of increasing apomictic plants output has been illustrated. The greatest induction of apomictic shoots in vitro has been reached by alternation of BAP cytokinin at concentration of 1mg/l and 2 mg/l on the background of GA3 amounting to 1,5 mg/l. Grafting with shoots in vitro on non-sterile rootstocks of pear (Pyrus communis) has increased the output of plants up to 80%. A cytological assessment of 9 apomictic samples is provided. The cytological analysis of samples of apomictic forms has certified the presence of simulative haploid parthenogenesis in pear.

Water-soluble carbohydrates, cytokinins, ABA, salicylic acid and microelements content's dynamics in wintering underground organs of P.alba and G.nivalis were studied. Correlation between substance's level and air temperature, ground freezing depth, snow layer thickness fluctuations was determined. The role of phytohormons and free sugars in adaptive potential realization are discussed.

Purpose. To develop a method of propagation, stimulation of rhizomes growth in vitro culture for the genus Miscanthus representatives and their adaptation in the open field without the use of greenhouse complexes for acclimatization and completion of growing. Methods. Biotechnological procedures, mathematical and statistical analyses. Results. Prescription of nutrient medium was developed for explants inoculation, sprouts propagation, rhizomes growth stimulation in vitro. Such sterile explants as seeds, buds to be removed from rhizomes, parts of stems with bud were placed on modified media with mineral portion by Murashige and Skoog (MS) that contained 0,5–1 dose of macroelements and one dose of microelements, vitamins (10 mg/l of thia­minum, 1,0 mg/l of pyridoxine, 1,0 mg/l of nicotinic acid and 1,0 mg/l of ascorbic acid) supplemented with amino acids (250 mg/l of glutamic acid, 3 mg/l of tyrosine, 3 mg/l of arginine, 2 mg/l of hydroxyproline), plant growth regulators [0,5–1,0 mg/l of GA (gibberelline acid), 0,2 mg/l of 6-BAP (6-Benzylaminopurine, 0,1 mg/l of NAA (α-naphtylacetic acid)] in different variations. After seed germination, buds emerging and sprouts formation 1–2 cm in height, for propagation purpose they were passivated on the medium of other composition that differed from previous one by the content and ratio of growth regulators, especially by a high concentration of cytokinins [6-BAP (0,4–0,5 mg/l), kinetin (0,5 mg/l), adenine (0,5 mg/k)] in different variations in presence of GA (0,2 mg/l). In order to stimulate rhizomes growth, microclones were transferred on media with other composition and ratio growth regulators (6-BAP (0,2–0,3 mg/l) + GA (0,5–1,0 mg/l) or 6-BAP (0,2–0,3 mg/l) + GA (0,5–1,0 mg/l) + NAA (0,1 mg/l), in other words, with a high content of gibberellins. After the formation of rhizomes 10–15 cm in length, miscanthus plants were planted out in the open ground. Stimulation of rhizomes initiation and elongation on appropriate nutrient media before Miscanthus giganteus, M. sacchariflorus and M. sinensis planting in vivo resulted in 100% adaptation and 100% survival of plants in the winter period without the use of greenhouse complexes. Conclusions. The method of miscanthus propagation in vit­ro and adaptation in the open ground was developed that included stimulation of rhizomes growth and favoured the increase of their length on media supplemented with gibbe­relline that guaranteed 100% preservation of microplants to be propagated from in vitro culture during adaptation in the open ground and acclimatization in winter.

The development features of four samples of apomictic plants during micropropagation are presented. These plants have been derived from embryos after pear pollination with the pollen of Chaenomeles japanica at 55 and 70 days of their development. Different responses of samples on the tested concentration of cytokinin (6BAP) and its combination with gibberell acid are shown. Tendency of increasing of the coefficient of the reproduction of separate numbers of apomictic plants has been noted under changing of BAP concentration from 1 mg/l to 2 mg/l or BAP combination with GA3. For the purpose of optimization of the stage of conglomeration forming (buds and shoots) BAP concentration 1 and 2 mg/l should be alternated in a passage on the background of GA3 1,5 mg/l. For the first time the origin of apomictic plant roots during rhizogenesis has been retraced and the anatomical structure of roots in conditions in vitro has been studied. Root formation in vitro occurs in internal tissues of a shoot. Roots of apomictic plants formed in vitro are primary as in plants developed in vivo.

Callusogensis and morphogenesis of anthers of apple scab resistant varieties have been studied, with picloram applied. Auxin activity of this preparation has been revealed as in the darkness so in the light. The callusogenesis efficiency of studied varieties varied from 26,0 to 83,3% subject to the concentration of picloram in the darkness and from 11,3 to 74,9% in the conditions of low light. We consider 4 mg/l in the medium to be an optimal level of piloram concentration so far as this concentration provides the best callusogenesis indices of the tested apple varieties. The callus formed in the darkness in the medium with picloram is knobby and dense of white or milky color. The callus formed in the light is intensively green or greenishwhite, denser, with distinctly outlined meristem hearths. Morphological characters of calluses obtained in the medium of picloram are stable over years. The roots of Yubiley Moskvy variety have been induced under auxin:cytokinin ratio 1 : 2 (picloram : BAP, cytokinin). The roots of Svezhest cultivar were obtained under auxin : cytokinin ratio 3:9 (picloram : BAP, kinetin). Formation of four buds was recored in Orlovskoye polesie variety under auxin : cytokinin ratio 1:20.