Fruit growing
and viticulture of South Russia

Annotation

The results of evaluation of short stratification periods with different durations influence the obtaining healthy microplants of sweet cherry hybrids from isolated unripe embryos in vitro culture are presented. Three sweet cherry varieties of super early, early and meddle term of ripening are studied. The sterilization scheme for immature sweet cherry embryos using a disinfectant in the form of tablets containing the sodium salt of dichloroisocyanuric acid was tested. The method showed the high efficiency, which was manifested in a low percentage of infected tubes. Three seeding were made at various times: after harvesting immediately, after 1 week, and after 3 weeks of stratification. The degree of plants development introduced in vitro culture was defined after 2, 3, and 5 weeks. Assessment of plants with root and leaves was carried out on a 5-point scale. Based on the development degree of plants introduced in vitro culture, a graph was created showing that the highest percentage of normally developing embryos of the Krasnodarskaya Rannya sweet cherry was observed in the group stratified for three weeks, than that stratified one week. In the group of the Krasa Kubani specimens, an opposite dependence is observed. The rate and degree of development of the Yaroslavna embryos without stratification are in the middle range between other studied samples with long and short stratification. Based on the data obtained, it can be concluded that the varietal characteristics of samples prevail over the duration of stratification in order to increase in the yield of normally developed microplants obtained in vitro embryo culture.

Annotation

One of the limiting factors of consistently high yields with good quality are various diseases of the crop. For example, diseases caused by phytoplasmas can have a serious negative impact the quantity of the crop and its quality, which can further affect the quality of wine products and profits. Phytoplasmas are one of the most dangerous phytopathogens. On grapes, they are represented by two species � Candidatus Phytoplasma vitis Flavescence dorée (causes Golden yellowing of grapes) and Candidatus Phytoplasma solani Bois noir. Many plant diseases that are thought to be caused by phytoplasmas were described before molecular genetic studies identified the various groups of phytoplasmas that cause these diseases. It is now possible to assess the relationship between the classification of phytoplasmas and specific plant diseases. Golden yellowing of leaves is a quarantine disease for the Russian Federation and the European Union and it causes a great damage to vineyards, so quick and accurate identification of this disease is very important. The main method for identifying phytoplasmas is real-time PCR (RT-PCR) with specific primer systems. The aim of our study was to compare the methods for extracting DNA from plant tissue affected by phytoplasma for further real-time PCR. This study showed that the samples isolated using the commercial kits "AgroDiagnostics" and "CytoSorb" show the similar results, while the sample isolated by the laboratory method based on the use of CTAB buffer showed higher and earlier peaks on the graph, which is important for detecting a small amount of pathogen in the test material and proves the greater effectiveness of this method of isolation.

Annotation

Control of varietal purity of planting material is a significant factor affecting the productivity of horticultural farms. SCoT markers (Start Codon Targeted) can be attributed to modern methods for monitoring the varietal purity of seedlings of fruit crops, which have the prospect of being introduced into wide practice. In this connection, based on the prospects of using SCoT markers in the identification of plant material, work was carried out to select effective combinations of SCoT markers. An approach based on the creation of markers from two SCoT primers was used to increase the number of possible marking options. The aim of this work was to select combinations of SCoT mark-ers that are promising for apple DNA fingerprinting, which in the future will allow the best combinations to be used in the identification of planting material. The paper presents the results of the evaluation of combinations of SCoT-markers to identify representatives of the genus Malus. The 18 SCoT markers were grouped into 68 combinations based on the preliminary assessment. The selection of effective combinations of markers was carried out according to a number of necessary criteria, such as the high quality of DNA finger-prints and a significant number of polymor-phic amplified DNA fragments. These characteristics are especially significant in the genetic assessment of closely related genotypes. The requirements for the quality of DNA fingerprints increase significantly, due to the large number of identical DNA fragments. About 45 % of the combinations were successful and were selected for fur-ther work as promising. The approbation carried out in the work made it possible to identify promising markers among 68 used ones. Selected DNA markers can be useful in a variety of areas, including the genetic identification of accessions, the analysis of the genetic homogeneity of plants obtained through micropropagation, as well as for performing research on the study of the genetic relationships of accessions.

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 ability to effectively protect orchards against apple scab is threatened by Venturia inaequalis developing resistance to fungicides with a particular mode of action. Three pathogen populations from orchards in the Krasnodar region were used in dose-effect tests to examine the susceptibility of the apple scab pathogen population to cyprodinil. One of the populations was collected in an abandoned garden and was the baseline. The rest of the populations are collected in commercial gardens with the annual use of fungicides, including cyprodinil. The effect of 7 concentrations of cyprodinil was determined: 0.001, 0.01; 0.10; 0.50; 1.00; 10.00 and 50.00 mg/l for the growth of monospore pathogen isolates on Leroux synthetic medium. A total of 63 fungus isolates were analyzed. The growth of mycelium on the fungicide was expressed as a percentage relative to the control variant of the medium. The concentration of fungicide active ingredient that resulted in a two-fold inhibition of growth, called the effective 50 % concentration (EC50), was found using a probit regression transformation of the relative mycelial growth on the active ingredient. Analysis of dose-effect curves showed hormetic responses at low fungicide concentrations. The results of the study revealed that the sensitivity of the original population was significantly higher than that of the two fungicidal populations at a significance level of p