Fruit growing
and viticulture of South Russia

Annotation

The materials of the study of agrochemical and microbiological indicators of leached chernozem in the orchard agrocenosis and field crop rotation are presented. The peculiarities of the distribution of the main elements of plant nutrition and organic matter by layers in the upper part of the soil profile, depending on the type of cultivated crop, are revealed. As a result of the evaluation of the main groups of microorganisms of leached chernozems, 830 strains of pathogenic and conditionally pathogenic micromycetes were identified, among which Aspergillus spp. and Penicilium spp. predominate. The number of micromycetes in the studied areas differs slightly, however, in the upper layer (0-10 cm) of soils under the garden cenosis there is a sharp increase in them. It has been established that in the soils of the orchard cenosis there is a fivefold decrease in the number of bacteria in comparison with soils in the conditions of field crop rotation. The number of bacteria gradually decreases with depth. Correlations of the total number of fungi strains and colony-forming units of bacteria on the content of organic matter, nutrition elements, the total amount of salts and the reaction of the soil environment have been established. A close correlation between micromycetes and bacteria (r = 0.99), humus (r = 0.95), mobile potassium (r = 0.93) and pH (r = 0.89) was revealed in the soils of orchard cenosis. There are no close correlations in the field crop rotation. Data on the ratio of bacteria and micromycetes indicate a higher suppressiveness of soils in the conditions of field crop rotation and the depletion of the microbial pool of soils of orchard cenoses. This indicates the development of the process of soil fatigue and a decrease in the resistance of leached chernozems to phytopathogens during prolonged cultivation of an apple orchard in a monoculture.

Annotation

Plum pox virus in stone fruit crop plantings is one of the factors increasing the cost of cultivation of these crops. Infestation of stone fruit crops can reach 41-50 % in the Russian Federation regions of the middle zone, which is a serious threat to the production process. Infection with this virus often causes drop of leaves, ovaries and fruits in susceptible varieties. Methods to combat this virus are expensive and difficult to implement in the technological process. The most effective approach is plantation monitoring and elimination of infected plants. Since PPV contains RNA in its structure, the assay must obtain a quality preparation of total RNA. To obtain information on the quality of the isolated RNA, internal positive controls of RT-PCR are often used. In this work, the method for identification of the plum pox virus using a duplex with an internal amplification control was perfected. The ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit gene was used as a control because of its stable expression and high mRNA copy number. The material for this study was leaves of Kabardinskaya ranniaya plum (Prunus domestica L.), collected in early and late May in Krasnodar (Krasnodar region). The analysis was performed using molecular biological methods of reverse transcription and polymerase chain reaction. Detection of amplification products was performed in 2% agarose gel. Plum pox virus was diagnosed in all examined samples of symptomatic material. Multiplex PCR with the primer pairs under study required the use of gradient annealing of the primers with a temperature change of 3.18 �C/sec. When using a cDNA matrix less than 50 ng/�l, a decrease in PCR quality is possible. A method for the diagnosis of plum pox virus using an internal amplification control was perfected and modified.

Annotation

The issue of obtaining planting material for fruit crops, free from pathogens, including viruses and phytoplasma, is of high relevance at the present time. The use of modern methods of biotechnology and molecular genetics is an important element in the production of improved planting material, since it allows not only to obtain plants in the culture of meristems in vitro and to produce their microclonal propagation, but also allows control the presence of viral and phytoplasmic pathogens, the identification of which by external symptoms can be difficult due to the presence of a latent form of disease. The article presents the results of the implementation of complex studies on microclonal reproduction of various crops of fruit crops, as well as an analysis of modern scientific literature on this topic. In addition, the results of molecular genetic studies in the part of the analysis of the genetic stability of plants obtained in vitro and the identification of viruses are presented. It was noted that at all stages of micropropagation, including the use of a culture of meristems, it is often necessary to develop variety-specific protocols. Optimal protocols for sterilization of explants of pome and stone fruit cultures using disinfecting tablets "OKA-TAB" and antimicrobial preparation �BIO-PAK� have been developed. The dependence of the intensity of the release of phenolic compounds by explants and their further necrotization upon introduction into culture in vitro on the phases of development and the age of donor plants was revealed. The optimal concentrations of nutrient media components, as well as phytohormones, have been established for a number of varieties and rootstocks of pome and stone fruit crops of domestic breeding. As part of the analysis of the genetic stability of plants obtained under in vitro conditions, ISSR and IRAP DNA markers have been identified that are promising for use for these purposes on apple stocks (ISSR: UBC 811, UBC 841 and UBC 843; IRAP: Cass 1 and �ass 2). When analyzing the genetic stability of the rootstocks of large-stone cultures using ISSR DNA markers, the identity of the DNA profiles was revealed, which testifies to the preservation of genetic stability for this rootstock using the developed micropropagation protocols. Based on the use of a complex of biotechnological and molecular genetic methods, genetically homogeneous rootstocks of stone fruit cultures, free from the virus pox disease of plum, were obtained. These plants, after testing for other viruses of stone crops and in the absence of such, will be transferred to the category of �candidates for initial� and, after retesting, can be transferred to the category of �initial plants� and serve as a basis for further mass production of virus-free rootstocks.

Annotation

Fruit crop virus has a negative effect on the timing of ripening and quality of fruit-bearing of plants. Virus free plants should be used for orchard set-up. Plum virus pox disease is a serious threat to horticulture because it has a wide range of host plants and able to spread in orchards in a short time. Methods for effective diagnosis of this virus are of high importance for the production of virus-free planting material. This work presents the results of testing and optimization of the method of plum virus pox disease diagnosis using PCR method with reverse transcription, as well as the evaluation of its effectiveness in comparison with commercial kit. Various tissues of PKSK 1, AI 1, VSL 1, and Gizela 5 rootstocks obtained in apical meristem culture and plum plants of Stanley cultivar ere used as the material. The concentration in the ratio of Oligo dT (Oligo(dT)15-primer) and Random (Random (dN)10-primer) primers we added was optimized (1:2), in order to increase the yield of specific viral cDNA fragments. The primer pair of the amplification control was matched to the region of the gene encoding the small subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase. For comparative evaluation, cDNA samples from plants obtained in vitro apical meristem culture and samples from symptomatic plants were used. After obtaining the preparation of total RNA, reverse transcription and amplification of the obtained cDNA were performed, followed by analysis of the products on an agarose gel. No nonspecific amplification products and single-stranded DNA were observed in the samples. Amplification products of positive controls were observed in all samples examined. The method we studied showed high efficiency compared to the control method.

Annotation

The wintering period and exit from dormancy are of great importance for the subsequent vital activity of grape plants. Induced dormancy is characterized by a number of specific physiological and biochemical changes. The aim of this study was to characterize the photosynthetic parameters, the carbohydrate composition of chlorophyll-containing vine tissue in the period of exit from dormancy. Studies were conducted on grape hybrids of TANA 33 (intraspecific hybrid V. vinifera), TANA 42 (interspecific hybrid V. vinifera and V. amurensis), TANA 68 (interspecific hybrid of V. vinifera and American varieties). TANA 42 and TANA 68 are non-freeze-sensitive hybrids, and TANA 33 is freeze-sensitive hybrid. The studies were carried out in February and March. Content of carbohydrates, photosynthetic pigments, the photochemical activity and the content of MDA in the vines were obtained. Physiological differences between grape hybrids with different freeze resistance during the induced dormancy were revealed. The lowering of the air temperature to moderate negative values have had a weak influence the manifestation of oxidative stress in non-freeze-sensitive hybrids, and a steady increase in the content of MDA was observed in freeze- sensitive TANA 33. The content of photosynthetic pigments in the vines cannot serve as an indicator of freeze- tolerance but this parameter was closely associated with the temperature changes. The effective quantum yield of PS Ⅱ in February was significantly lower for the freeze-sensitive TANA 33, however, the differences between the varieties disappeared after the onset of sap flow. The quantum yield of PS Ⅱ was depended on the temperature changes. The adaptation of non-tolerant grapes probably accompanied with the transformation of starch into soluble carbohydrates, which was not typical for frost-resistant varieties.