PROSPECTS FOR GENETIC RESOURCES REPRODUCTION OF THE MAIN FOREST-FORMING GYMNOSPERM SPECIES IN UKRAINE BY BREEDING IN VITRО

Abstract

Effective breeding of the main forest-forming gymnosperm species of Ukraine (Pinus sylvestris L., Larix decidua Mill., Abies alba Mill. And Risea abies (L.) Karsten), which are of significant value for Forestry and Landscape Architecture, is a very important task. The solution to this task may be the use of modern methods of reproduction, namely in vitro micro-cloning. Decontamination of explants was conducted applying the following sterilizing agents in different concentrations and in different combinations: tapwater (H2O) withadetergent; Medicalethanol (C2H5OH); sodiumhypochlorite (NaClO); silvernitrate (AgNO3). To prevent internal infections, a 0.1% "Imaninum" antibiotic was applied. To initiate explants, the following nutrient media were used: Murashige and Skoog (MS), Risser and White (RW) and Litvay (LM), which were modified with phytohormones: 2,4-D; NАА; IВА and BAP. Rooting of the obtained clones was performed on 1/2 MS and 1/2 LM media, supplemented with auxin (2,4-D; NАА IАА and the IВА). Adaptation of clones to ex vitro conditions was exercised in the sod soil and sand (1: 1) and sod soil with peat and sand (1: 1: 1).Thefollowingsterilizationresultswereobservedin: PinussylvestrisL. – 98, Larixdecidua Mill. – 96 Abiesalba Mill. – 98 and Riseaabies (L.) Karsten– 97 % ofasepticexplants. The proper selection of nutrient medium resulted in high initiation of: Pinus sylvestris L. – 92, Larix decidua Mill. – 95 Abies alba Mill. – 94 and Risea abies (L.) Karsten – 95%. The importance of the auxin and cytokinin presence in the medium at this stage should be noted. Rhizogenesis results of the study species are as follows: Pinus sylvestris L. – 86, Larix decidua Mill. – 91 Abies alba Mill. – 93 and Risea abies (L.) Karsten – 89%. It is established that injection of IАA to the medium is necessary, since the number of rooted clones was only increasing during all scenarios. The largest number of adapted clones was observed on the substrate of sod soil with peat and sand, except for the plant-regenerants of Larix decidua, where the substrate of the sod soil and sand had given a better result. Application of in vitro breeding for the study species is very promising, since satisfactory results were obtained at all stages. A further study of cultivation phase is necessary, since it will enable to determine the rate and stage of adaptation to in vivo conditions.

Keywords

• forest-forming species
• breeding
• in vitro
• explant
• decontamination
• initiation
• rhizogenesis
• adaptation