Growing nut crops is a powerful promising area for growing agricultural products for export in Ukraine. Demand for nut products, as well as oilseeds, exceeds supply. However, today the country has unmet demand in the domestic market, which creates conditions for the intervention of imported fruits. Effective protection of the domestic producer of nut products is not to increase the import duty on it, but to create new competitive varieties and to develop technologies for their accelerated reproduction.
The process of vegetative propagation of woody crops is long, and especially nut, labor-intensive, and for the walnut is almost impossible. Therefore, the efforts of many researchers are aimed at developing industrial technologies for microclonal propagation (MCR) of hazelnuts and walnuts. Their use will increase production and expand the range of planting material and export products.
However, the microclonal propagation of nut crops has not yet gone beyond scientific laboratories. The complexity of such technological methods as introduction into aseptic conditions (self-poisoning by phenolic exudates, hyperhydration as a result of traumatic shock, etc.), stabilization of plant objects in the process of multiplication (selection of optimal trophic and hormonal determinants, methods of division of donors), induction of rhizogenesis and post-septic adaptation (including mycorrhiza of plants in vitro / ex vitro).
This leads to the intensification of scientific research of cytological, physiological, technological and organizational methods of improving technology and bringing it to the industrial level.
Another important issue is the creation of source material that can survive effectively in drought, especially in the early stages of plant development. After all, droughts are already occurring throughout Ukraine, and with little development of the root system, hazelnut and walnut seedlings have a fairly low survival rate when planted in open ground. Therefore, the study of these and other issues is quite relevant.
For the first time, schemes of cell selection and induced mutagenesis in vitro for hazelnuts and walnuts were developed and proposed, which allow to obtain callus lines and regenerating plants with increased resistance to osmotic stress.
Received further development: the use of hazelnut and walnut in cell selection for drought resistance of γ-irradiation with subsequent cultivation of callus cultures with polyethylene glycol and mannitol.
It has been experimentally established that the increase in resistance at the cellular and tissue levels is preserved at the level of regenerating plants of hazelnuts and walnuts.
Based on the results of laboratory studies and their experimental verification, a scientifically sound system of application in the selection of hazelnuts and walnuts with prior use of induced mutagenesis has been developed. The results of the work can be used to create new high-yielding drought-resistant varieties of hazelnuts and walnuts.
Cultivation of plants is carried out on DKW medium, which provides the formation of the largest number of micro-shoots - 3.6 pcs. compared to 1.8 pcs. on QL media and 2.1 pcs. of MS.
To overcome the problems of phenol production, we offer a number of measures: cultivation of mother plants in diffused light in the depository; the use of the antioxidant ascorbic acid for soaking explants before sterilization; introduction of plants by allocation of meristems, awakened buds; addition of PPM (Plant Preservative Mixture) biocide to the nutrient medium; adding to the nutrient medium PVP (polyvinylpyrrolidone).
At the stage of multiplication, 1.5 mg/l of benzylaminopurine is added to the nutrient medium. This concentration contributed to the formation of an average of 4.8 pieces. micro shoots with a high growth rate and a low percentage of vitrification of 2 %.
For successful rhizogenesis, the medium is modified by adding 2.5 g of activated carbon and auxin of indolylbutyric acid in the amount of 3.0 mg/l. Adding 2.5 g of activated carbon provides the formation of the largest number of roots – 2.3 pcs. at 3 mg/l IMC in the nutrient medium and increases the number of roots from 0 in the control to 2.5 pcs.
At the beginning of post-septic adaptation, the plants and the substrate are sprayed with the fungicide Previkur Energy 840 sl v.r.k., which provides better survival of plants. In addition to fungicidal protection, the drug stimulates growth processes, which is manifested in an increase in plant mass.
