MICROCLONAL REPRODUCTION OF HAZELNUTS

Abstract

For the rapid introduction of large quantities of high-quality hazelnut planting material, it is important to use various modifications of microclonal propagation: classic on gel media, bioreactors with periodic flooding (TiS) and photoautotrophic methods. At the first stage of classical methods there are three main problems: phenol formation; endogenous contamination; selection of trophic and hormonal determinants of in vitro ontogenesis. In cases of infection of mother plants with viruses, viroids, it is mandatory to use meristem explants with a size of not more than 0.3 mm, followed by diagnosis of the effectiveness of recovery. To prevent self-intoxication with phenol-like oxidation products, a set of measures is used to prepare explant donors and modify nutrient media. The most common artificial nutrient media are Driver and Buzzard (DKW) and Nas and Read (NRM). Hazelnuts are sensitive to excess nitrogen and calcium and copper deficiency in artificial nutrient media. On media with a high N content, regenerants have shortened and thickened shoots, often with signs of hypehydration. Inhibition of calcium uptake by nitrogen leads to necrotization of shoot tips and root tips. The incorporation of iron ions into the metabolism of a plant depends on their valence and the form of chelating agents. During the multiplication and induction of rhizogenesis in aseptic conditions, mainly synthetic cytokinin benzylaminopurine and auxin indolylbutyric acid are used. The effectiveness of hormones increases with the use of combinations within groups, in particular cytokinins are benzylaminopurine and kinetin. At the stage of multiplication there is a predominance of cytokinins over auxins, and at the stage of rhizogenesis the number of auxins in the environment is greater than the number of cytokinins. Of the organic components, vitamins B1, B6, C, PP, amino acids and inositol are added to the environment. Ex vitro acclimatization of plants is carried out on peat-pearlite substrates in closed soil or modules of photoautrophic microclonal propagation with increased light intensity and high carbon dioxide content. The photoautotrophic method combines animation, rhizogenesis and acclimatization at the same time. The effectiveness of adaptation to factor-nestatic conditions increases with mycorrhizae by fungi of the genera Glomus, Trichoderma, Tuber in the transfer of plants from aseptic conditions.