Fruit growing
and viticulture of South Russia
Breeding and production of planting material
To improve the organic nutrition of a grape plant in in vitro culture, studies were conducted on the effect of sucrose on the development of test-tube plants. Despite the fact that sucrose is the most commonly used and sufficiently studied source of carbon in in vitro nutrient media, at this stage of the study, it was necessary to clarify and compare the response of specific model varieties to various concentrations of sucrose, and also to obtain, at the end of the experiment, a sufficient number of microplants for further stages of research. Two varieties with diametrically opposite characteristics of development in in vitro culture were taken for the study. The Sibirkovyi variety was chosen as one of the fastest growing and, accordingly, the fastest aging (in vitro culture) varieties, and Krasnostop Karpi is one of the slowest developing varieties in in vitro culture. In addition, these varieties also differ genetically. Sucrose concentrations from 0 to 40 g/L were used in the experiment. The varietal reaction of model varieties in the experiment with different concentrations of sucrose in the nutrient medium showed both general patterns and minor differences. For the Sibirkovyi variety, the optimal concentrations for the development of most indicators of microplants were in the range from 5 to 20 g/l, and for the Krasnostop Karpi variety 5-10 g/l. There was a clear tendency to decrease the root length index with a decrease in sucrose concentration below and an increase above 30.0 g/l in both varieties. The best indicators of development and preservation in a year were noted in the variant where sucrose was not used at all, the variant with the lowest concentration of sucrose, 5.0 g/l, was slightly inferior to it. At the same time, at high concentrations, despite the worse preservation, a slowdown in the growth processes of the shoot and its maturation in some plants were noted.
In vitro micropropagation of garden strawberry and the establishment of micropropagation protocols are important tools for obtaining large quantities of planting material. In recent years, significant efforts have been made to propagate berry crops in vitro in order to obtain virus-free plants of high quality. However, despite the large number of studies on micropropagation of garden strawberry, the modification of the main method remains relevant today, since each variety has its own specific requirements for in vitro cultivation conditions. In this regard, the purpose of the study was to determine the characteristics of clonal micropropagation of garden strawberry variety Malvina. As a result of the work carried out, it was noted that it is effective to use a 0.5 % aqueous solution of OKA-TAB disinfectant tablets for sanitation of strawberry explants of the Malvina variety (exposure 5 minutes). The processing efficiency was 82.5 %. It has been established that at the stage of micropropagation of the strawberry variety Malvina, it is most effective to use the Murashige-Skoog medium with a kinetin content of 1.0 mg/l, which allows to obtain up to 15 shoots per explant. It was revealed that the strawberry root formation proceeds effectively on a hormone-free environment, in which from 4 to 6 roots are formed, the percentage of root formation was 95 %. The use of the microbiological preparation «EM Bio» at the stage of acclimatization of garden strawberry microplants to non-sterile ex vitro conditions contributed to an increase in the intensity of vegetative growth by 45-50 %. The plants had a stronger root system (56 % longer than in the control), and a higher adaptive capacity to ex vitro conditions.
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.
The article presents the results of evaluating the efficiency of propagation of garden strawberry varieties under in vitro conditions. The paper compared the strawberry varieties of the Italian selection Asia, Cleri, Quicky and the varieties of the selection of the Federal State Budgetary Scientific Institution NCFSCHVW Nelli, Taira and Kemia. At the stage of introduction into in vitro culture, the Nelly varieties have a high level of regeneration 80 %, Kemia and Asia 73 %, Taira 70 %, Clery 62 %. The survival rate of explants Quicky variety was 34 %. A gradual increase in the concentration of 6-BAP during strawberry micropropagation increases the formation of strawberry shoots with each passage. An increase in the concentration of 6-BAP to 0.75 mg/l at the second passage contributes to an increase in the number of shoots by 1.5-2.7 times, depending on the genotype, and is 3.5-10.2 shoots. Increasing the concentration of 6-BAP to 1.0 mg/l at the third passage increases the number of shoots formed by another 8.9-31.4 % compared with the second passage and amounts to 5.1-11.3 shoots, depending on the variety. Thus, the varieties Taira, Nelli and Asia have a high breeding efficiency under aseptic conditions, on media with different hormonal composition, in total 22.7-26.0 microshoots per 3 passages, the average varieties Clery and Kemiya 13.7-14.8 shoots, low variety Quicky 10.7. The efficiency of rhizogenesis of regenerated plants of the studied strawberry varieties on a hormone-free Murashige-Skoog medium with half the content of macrosalts is 95-98 %. The successful rate of adaptation of microplants of the studied varieties ranges from 87 to 95 %.
Medlar has a limited distribution in modern orchards. Industrial plantings of medlar in the Russian Federation are absent, among other things, due to low germination of seeds and slow growth of seedlings, which significantly complicates the cultivation of seedlings on seed rootstock. In 2021-2022, studies on the use of quince as a rootstock in the cultivation of German medlar seedlings were conducted at the educational and experimental field of Kabardino-Balkarian State Agrarian University. The results of experiments with inoculation of two varieties of medlar on quince showed that during budding and spring grafting with a cuttings, the survival rate of the inoculation components and further growth of seedlings does not differ from other seed crops, the intensity of growth processes is not inferior to pear trees grafted on quince (the control variant the pear variety Talgarskaya Krasavitsa has a high degree of compatibility with quince A). On average, in 2 years for both varieties of medlar, the survival rate of grafting eyes was 90%, and grafted cuttings 83%. In the control (pear on quince), these indicators were noted at the level of 92.0 and 84.8%, respectively. The height of medlar seedlings (on the stock of Quince A) in autumn was 140 and 133 cm (depending on the grafting options), and for pears grafted on quince A 152 and 130 cm, respectively. Due to the fact that the difference in survival rate between the studied variants and the control is insignificant, it is proposed to use Quince A as a rootstock when growing seedlings of the German medlar.