Fruit growing
and viticulture of South Russia

Annotation

The yield capacity of tea plantations, the quality of the collected raw materials directly depends on the amount of precipitation, especially in summer. In this regard, the efforts of scientists are aiming on studying the physiological, biochemical and molecular mechanisms of tea plants resistance to high temperatures. Stress induction in vitro is an alternative tool for studying these processes in depth. To select drought-resistant genotypes, we simulated moisture deficiency in vitro by adding a selective agent, polyethylene glycol (PEG � 30 g/l), to the nutrient medium. Osmotic stress was studying by conductometric method, in terms of the electroconductivity of tissues and the stability of cell membranes. Of the whole studied group of tea somaclones, only somaclone Sc-27 did not have an increase in the electroconductivity of leaf tissues and a reduce in the stability of cell membranes, which indicates its resistance to water deficiency. On these positions tissue damage in another plants, caused by the action of osmotic stress were observing. The research protocol also included the study of level expression the dehydrin 2 gene � DHN2, as the most informative genetic marker of drought resistance. Conducting PCR analysis showed that under water deficiency caused by the addition of PEG to the nutrient medium, the dehydrin 2 (DHN2) gene showed a high level of expression of Sc-27 somaclone. This confirms the direct relationship between the action of osmotic stress and the level of this marker expression. Significantly increased the expression of DHN2 gene with the addition of PEG, confirms the water deficiency in tea microplants, which is a trigger for the production of DHN2. Thus, during of osmotic stress inducted in vitro, among the studied somaclones of tea, Sc-27 demonstrated high adaptability to water deficit. The PCR analysis confirmed this by showing that the marker of drought resistance, the dehydrin 2 gene, were expressing much higher.

Annotation

The studies were carried out in accordance with the programs and methods of breeding and variety study generally accepted and developed at the FSBSI NCFSCHVW in the Center for Collective Use �Research and Breeding Collection of Genetic Resources of Horticultural Crops� (CCU RBC GRHC). The objects of research are varieties and forms of apple trees (Malus × domestica Borkh.) of different ploidy and genetic origin. The aim of the study was to evaluate the allelic polymorphism of microsatellite sequences in the genome of collection specimens of the genus Malus Mill. as a starting material for further breeding. Genotyping of 48 apple varieties (of which: 44 diploids and 4 triploids) of the genetic collection of the FSBSI NCFSCHVW was carried out using 12 SSR markers: CH04c07, GD12, CH03d07, CH02C09, CH01h10, GD96, CH04e05, GD100, Hi02c07, GD147, CH01f02, CH02c11. Markers have been established that have: the largest number of alleles � GD12 (18 alleles); the smallest number of alleles � CH01h10 and Hi02c07 (10 alleles); the largest number of effective alleles � CH01f02 (9.018) and CH02c11 (9.366); the smallest number of effective alleles � CH01h10 (3.499). According to the diversity index, loci CH01f02 and CH02c11 were identified as having the highest allelic polymorphism. The grouping of the studied 48 apple varieties was performed based on the results of genotyping for the two most informative markers (CH01a02 and CH02c11) and cluster analysis. The highest average allele length (2480.40) is in the varieties included in the third cluster, then in the second cluster (1019.66), in the fourth cluster (819.65) and in the first cluster (603.28). 4 groups consisting of 7, 3, 22 and 16 varieties, respectively, were formed according to the average length of alleles. The results of the analysis of this sample of apple varieties are important for solving the problems of structuring the gene pool and further breeding studies.

Annotation

Drought resistance of plants is the ability of plants to withstand the significant dehydration and overheating of their organism, the ability to survive during drought with the least decrease in yield capacity. Heat resistance (heat tolerance) is the ability of plants to withstand the high temperature effect and overheat. Seed crops were studied: pear forms PG 12 (control), PG 17-16, PG 2, K-1, K-2, Kavkazskaya, OHF 333, Piro II, 4-26, 4-39 and quince forms Severnaya, BA 29, studies were conducted on the resistance of pear and quince forms to drought and heat resistance in laboratory conditions. The zoned pear form PG 12 was used as a control. In this regard, the purpose of our research was a set of measures to assess the initial forms of pears and quinces for drought and heat resistance. As a result of the research, it was found that moisture retention index varies significantly in the studied pear and quince forms. The pear forms PG 2, K-2, Kavkazskaya and quince form BA 29 were characterized as highly resistant to drought, in which water loss was from 8.2 to 21.8%, and the degree of water was from 50.0 to 100.0%. Water deficit in these forms was within 4.4 - 7.1%. The highest water-holding capacity was observed in pear PG 17-16 � 79,5 %, Kavkazskaya � 80,9 % and quince B� 29 � 86,6 %. The water-holding capacity of the pear form K-2 was 67,3 %. When evaluating the heat resistance of pear and quince forms, the differences in the resistance of these forms to the action of temperatures were revealed. A good water-holding capacity after exposure to stressful positive temperatures is preserved by the pear form Kavkazskaya, which has a water deficit of 4,8 %. At the same time water-holding capacity was 70,9 %, water loss � 19,1 %, degree of water content � 38,4 %.

Annotation

The cultivation of a number of crops (especially stone fruit, with a short dormant period) in the south of Russia is determined mainly by the temperature factor. The biological potential of sweet cherry adaptability is limited by the temperature limit equal to minus 27.0�28.0 º� in winter, from minus 2.5 to minus 8.0 º� in spring, depending on the degree of development of the flower organs. As a result of exposure to low critical temperatures at various phenological phases of development, yield losses are possible up to 80-95 %. The study revealed the climatic factor that had the greatest impact on yield capacity � the annual precipitation (R=0.381). Other factors did not significantly affect the formation of productivity: the average annual air temperature (R= 0.167), the sum of temperatures above +10 º� (R= 0.160), the absolute minimum temperature (R= 0.007). Various weather stressors have been studied over the last 10 years of observations, which led to a significant loss of the yield of sweet cherry varieties. The most unfavorable years were 2014, 2017 and 2020, when 80-95 % of sweet cherry fruit buds died due to early frosts and return freezings. The yield capacity in these years decreased from 5.0-10.0 kg per tree to single fruits, depending on the variety. Against the background of the manifestation of weather anomalies, resistant varieties were identified � Alaya, Dar izobiliya and Volshebnitsa. In years with favorable abiotic factors, sweet cherry is able to form up to 45-50 kg of fruit per tree, such conditions prevailed in 2021. In some varieties, the yield capacity reached 60-65 kg per tree, these include Alaya, Dar izobiliya and Kavkazskaya. In addition, an indicator was determined that significantly affects the yield capacity, � the number of fruit buds (R= 0.840), which also directly depends on weather and climatic factors

Annotation

The selection of highly effective rootstocks for new grape varieties is relevant in modern viticulture. The influence of different rootstocks Chasselas × Berlandieri 41B and Berlandieri × Riparia SO4 on the agrobiological indicators of the Livia grape variety in the Central agroecological viticulture zone (fourth subzone) of the Krasnodar region is shown. The planting scheme of bushes on irrigated vineyards in the field experiment is 3.8 × 2 m, the formation of bushes is a high-standard two-armed cordon. The soils are low-humus, leached powerful chernozems. The average annual air temperature is 12.5-13.0 º�, the sum of active temperatures is 3900-4100 º�. The annual total precipitation is 700-800 mm. Grapes of the Livia variety on the 41B rootstock significantly outperform the analogue on the SO4 rootstock. Plantations on rootstock 41B are distinguished by a larger mass of bunches, elegance, large size and organoleptic properties of berries, and grape yield capacity. Ripening on rootstock 41B started much earlier than on rootstock SO4. In the agro-ecological conditions of 2020, the difference was 13-17 days, in 2021 � 4-7 days. Mass ripening in 2020 was earlier by 7-20 days, in 2021 by 6-7 days. The average weight of a bunch on the 41B rootstock was 30% more than on the SO4 rootstock and amounted to 0.674 kg. In terms of grape yield from a bush, plantings on rootstock 41B exceeded the analogue by 1.5 times. The yield capacity of grapes on rootstock 41B was higher than on SO4 by an average of 1.5 times and amounted to 24.62 t/ha. The share of marketable grapes was 93% on rootstock 41B, on rootstock SO4 � 90%. The tasting score of grapes grown on rootstock 41B was on average 8.8 points, on SO4 � 8.1 points. The positive effect of rootstock 41B on the biological and economically valuable characteristics of grapes is the basis for the wide practical use of this rootstock for the Livia grape variety in the Central agro-ecological viticulture zone of the Krasnodar region.