Fruit growing
and viticulture of South Russia

Annotation

As a result of study of Coccomyces populations the endophytic microbiota is defined and stability of stone fruit forms to disease is estimated. The necessity of a comprehensive study of population structure of the pathogen in the place of expected growing is established using the definition of endophytic microbiota

Annotation

To increase the productivity and stability of fruiting of plants, the horticulture industry needs the adaptive varieties and rootstocks in the specific growing zones. Based on global and local changes in weather and climate conditions, the selection of genotypes resistant to the most often occurring stresses of various types is a permanent process. The paper shows that in recent years, the directions in breeding to create the rootstocks forms that can reproduce under the conditions of elevated temperatures in the spring-summer period and a significant lack of moisture are especially relevant. The most of interest are rootstocks, which easily rooted by hardwood cuttings in the first field of the nursery, because this is the least costly method does not required large capital investments. Such rootstocks had already identified in the nursery as heat-resistant and drought-resistant, significantly increase in the adaptive potential of scion-rootstock combinations with their participation. An equally important characteristics in the South of Russia is the resistance of rootstocks to the bacterial cancer (Agrobacterium tumefaciens). The pathogen of root cancer is positively affected by a neutral or slightly alkaline soil environment, therefore this disease is often observed in the North Caucasus and its harmfulness is significant, the control disease measures are costly and difficult. As a result of research, we carried out the rootstocks of PK SK 1, PK SK 2 with high rooting of hardwood cuttings in the first field of the nursery and resistance to root cancer were selected. They were allocated to the elite and patented and introduced in the State Register of Selection Achievements. The use of these rootstocks in horticulture and nursery farming will allow us to use the resource-saving technologies and to obtain the high-quality planting material for stone fruit crops and to increase in the yield of fruit orchards.

Annotation

Adverse weather conditions promote the spreading of phytopathogenic microorganisms that in turn is the reason of thinner of gardens and uterine plantings. For satisfaction of needs for qualitative landing material it is necessary to use the rootstocks with high degree of resistance to an adverse effect of abiotic and biotic factors. The greatest economic danger has such widespread disease as an apple-tree scab. The purpose of work is screening on resistance to V. inaequalis of various rootstock's forms of an apple-tree under natural conditions of a garden for selection the most perspective forms on this sign. The objects of research are 72 rootstock's forms from a genetic collection of an apple-tree of Michurinsk Agricultural University. Microorganisms of Venturia inaequalis (Cocke) of Wint., Alternaria alternate (Fr.) Keissl. and a bacterium from the sort of Pseudo-monas, selected from the sick tissue of plants, were studied under the conditions of clear culture. The assessment of a phytosanitary condition of uterine plantings was carried out according to the standard techniques visually, and also using the microscope methods and by testing for existence of an infection. On the basis of phytosanitary evaluation of clonal rootstocks of apple plantations is revealed an associative type of lesion by microbiota with dominate of Venturia inaegualis (Cocke) Wint. The role in the pathogenesis of microorganisms belonging to the association is established. The stability of a population of clonal apple rootstocks to scab on the natural infectious background of hybrid garden is studied. The genetic differentiation of forms on this trait is revealed. It is shown that over 80% of the genotypes have a minor lesion by scab - to 2 points. Symptoms of lesion are not observed in 5 % of genotypes. These forms we recommended for breeding and production.

Annotation

The development of methods for determining the adaptive ability of plants to adverse abiotic and biotic factors is an important direction in many fields of science (ecological genetics, epiginetics, genetics of quantitative traits, biochemical genetics, ecological genetics, plant immunity, physiology, phytopathology, etc.). The study of plant microbiota allows a comprehensive assessment of their adaptability, similar to studies conducted on animals. The characteristics of the plant itself, the stage of its development, the reaction of the host and endophyte to external conditions affect the composition and structure of the endophytic community. These complex interactions play a role in the manifestation of the plant's phenotypic traits, including its ability to adapt to ad-verse abiotic and biotic factors. Combined breeding and biocontrol strategies are necessary to maintain the balance of ecosystems. Testing of rootstock forms of small-stone cultures showed the presence of endophytic microorganisms in the internal tissues of stem explants. Among the isolated bacteria, representatives of the genera Pseudomonas and Bacillus dominated. Fungi were represented by necrotrophs (Penicillium, Alternaria, Fusarium). Endophytic bacteria showed antagonism to isolated pathogenic fungi. It was revealed that in genotypes with a high level of adaptation to abiotic and biotic adverse factors, fungal pathogens are isolated from internal tissues in less than 15 % of all tests. Bacteria predominate and are detected in more than half of the tests. Therefore, it is important to determine the nature of the effect of endophytic bacteria on plant tissues by the degree of their necrotization in the presence of the studied microorganisms. According to the indicators of bacterial and fungal microbiota development, as well as the degree of necrotization of plant tissues under the influence of endophytic bacteria, the most promising genotypes were identified among the studied rootstock forms of small-stemmed cultures: VSL-2, 3-93, 5-40, 3-21, 3-110, 11-17, 5-44, 10-13 (2009 - 2010); Gisella D, Gisella 5, 3-76 (2021).

Annotation

It is necessary to use measures aimed at increasing the resistance of the host infection in combination with measures to weaken parasites in management of phytopathogenic microorganisms. The realization of the maximum productivity of plants is achieved with a high level of their resistance to adverse abiotic and biotic factors. This can be done with the use of growth regulators. Preference is given to preparation that meet the requirements of environmental safety, which include Zircon. The research was made in the scientific fundamental research laboratory "Biophotonics" of the Michurinsky State Agrarian University and the I. V. Michurin Federal Research Center. A solution of toxic metabolites of the Pseudomonas syringae van Hall bacterium was obtained by culturing it on a liquid nutrient potato-glucose medium. The working solution of the drug Zircon was prepared according to the manufacturer's recommendations. Experimental variants: leaves placed in water without treatment with Zircon (control variant); leaves in a 10 % solution of toxic metabolites of bacteria without treatment with Zircon; leaves in a 10 % solution of toxic metabolites of bacteria treated with Zircon. Diagnostics of the functional state of photosynthetic cherry tissues was performed non-destructively on a portable chlorophyll fluorimeter PAM-Junior. On the 10th day after the experiment was initiated, the activity of photosynthetic cherry leaf tissues in the variant using toxic metabolites was 0.507 cu, which is 16.9 % lower than the control value (0.610 cu). At the same time, joint treatment with Zircon and a solution of bacterial metabolites contributed to an increase in this indicator by 33.7% compared to the variant where only toxin was used and by 11.1% compared to the control. Thus, this preparation helps to increase the activity of photosynthetic tissues and the resistance of the host plant to the action of toxic metabolites of the bacterium.