Fruit growing
and viticulture of South Russia
Phytosanitary condition of plants
Downy mildew is a vine disease caused by the obligate heterothallic biotrophic endoparasite Plasmopara viticola. The area of distribution of this pathogen are vineyards all over the world, but the greatest losses are in the viticulture zones with a temperate continental and subtropical climate. In Krasnodar Territory, epiphytotic development of mildew occurs 6-7 times in 10 years. The first molecular genetic studies of the pathogen began at the end of the 20th century. The purpose of this work is to evaluate, based on DNA marker analysis, the polymorphism of the P. viticola population in two generations of the pathogen on grape plants growing in an isolated geographic point. The material for the study was the affected grape leaves taken from the vegetation plot of the FSBSI NCFSCHVW, from plants without chemical treatment. The material was taken in two time intervals the end of July (the first generation of the pathogen 4 samples) and the middle of August (the second generation 6 samples). To study the diversity, highly polymorphic SSR-markers GOB and PV144, were used. P. viticola DNA was isolated directly from infected leaves by the CTAB method. A total of 10 DNA samples of the pathogen were analyzed. The study was carried out by the classical method of polymerase chain reaction. The size of the target fragments of the PV144 and GOB loci was estimated using an ABI Prism 3130 automatic genetic analyzer by fragment analysis. The data obtained were analyzed using Gene Mapper 4.1 software. The highest degree of polymorphism was found for the GOB marker 7 types of alleles and to a lesser extent PV144 4 types of alleles. It was found that the samples of the pathogen population collected during the first generation have significantly higher genetic polymorphism, in contrast to the samples collected during the second generation. Research in this direction continues.
With the climate change on the planet towards warming, the fungi of the genus Alternaria Nees became more active. Due to the prevailing climatic conditions, some species of this genus changed their status and acquired signs of facultative parasitism and complete parasitism on a number of cultivated plants, including the apple-tree. In vitro scientific studies are required to effectively control the disease, in the pathogenesis of which a large number of species are involved. At the same time, it is necessary to achieve fast and guaranteed growth of each of the fungus in the experiments. In this regard, the selection for fungi of the genus Alternaria, causative agents of apple fruits core rot, optimal for the cultivation of nutrient mediums is urgent. The studies were carried out by methods of laboratory and comparative analyzes. The growth of two strains of the causative agent of the apple fruit core rot of Alternaria alternata (Fr.) Keissl. on 12 nutrient mediums. Colony growth rate and morphological and cultural traits were assessed. As a result of research the strains of apple fruit core rot agent, a variation not only in the growth rate of colonies, but also in their cultural characteristics, depending on the compositions nutrient medium. A comparative study of the morphological and cultural characteristics of A. alternata strains FR20IV and FR20VI on various nutrient mediums made it possible to identify three universal mediums most suitable for their cultivation and identification, namely carrot, potato agars and Sabouraud's medium, according to the following criterions: ensuring the maximum degree of sporulation, rapid growth and development of the mycelium of the fungus, as well as easiness of preparation of revealed optimum cultural mediums.
This review was carried out on the topic of bacterial population of grapevine, with an emphasis on the functional structure of these communities. Bacterial communities in microbiota of grapevine are the most numerous. According to the localization on the plant, the non-pathogenic part of the microflora is divided into endophytic, which occupies the internal spaces of the grapevine, and epiphytic, which occupies the surface. Most bacterial endophytes do not have a noticeable effect on grape, or this effect has not been studied, but it is known that some of bacterial endophytes can have beneficial effects, for example, to stimulate plant growth or prevent harmful effects of phytopathogens. Epiphytic microflora provides the primary immune barrier in the formation of non-specific immunity in plants. Surface bacterial communities of grapes are vary significantly depending on the occupied ecological niches: roots, leaves, bark, flowers, berries, seeds. The article outlines the role of bacterial communities in ontogeny of grapes and opportunities for its practical use to increase in immune resistance of the grapes. In the literature, there are references to at least twelve genera of bacteria isolated from the microbiota of grapes and exhibiting the antagonistic properties to its pathogens. Species of the Bacillus genus are especially actively used in this area. The factors that form the quantitative and qualitative composition of bacterial microbiota were indicated: anthropogenic, naturalgeographical, edaphic, and genotypic (varietal). Anthropogenic factors have the greatest impact. The direct impact the microbiota in this case is expressed in the introduction of agrochemicals and pesticides, and indirectly associated with pruning, grafting, forming bushes, etc. It is known that the nature of the microbial community varies considerably in the vineyards with organic management.
The results of study of the developmental features of the causative agents of monili Monilia laxa (Aderh. & Ruhland) Honey (syn. Monilia cinerea Bonord.) nd Monilia fructigena (Pers.) Pers. on the plum-tree in the Krasnodar Region are presented. The work was carried out on the plum variety of Kabardinskaya rannyaya according to generally accepted and adapted methods. The aim of the work was to identify the bioecological features of the development of monilia pathogens, in changing weather conditions, to optimize the protection technology. The main method of overwintering the causative agents of monili in the region is the mycelium located on the affected tree organs and mummified fruits. A number of features of the causative agents of monili on the plum-tree were identified in connection with the change in weather conditions: the temperature at which the primary infection with the pathogen M. laxa + 3.0...8.0 ºC is noted; the duration of the incubation period for M. laxa is 2 - 3 days at an optimum temperature of +22 to + 26 ºC and an air humidity of 70 to 95 %. For fruit rot 3-5 days; the period from infection to the appearance of sporulation is 8-10 days at temperature of + 24- + 28 ºC. The regularity of the expansion of the temperature range during the growing season is established: M. laxa from +10 to + 30 ºC, for M. fructigena up to + 38 ºC. For the first time, the simultaneous presence of two types of monili M. laxa and M. fructigena on the affected plum fruits was noted, which indicates an increase in the aggressiveness of the pathogen. The research results will make it possible to determine a strategy for optimizing the phytosanitary state of plum plantations and to develop protection against monili. For effective control of the disease, it is necessary to carry out the treatments at the beginning of plum blossoming, as well as in the first week of the manifestation of infection on the fruits.
Currently in all countries with commercial viticulture, special attention is given to grape varieties with group resistance to biotic and abiotic environmental conditions, due to the fact that the problems of ecology and environmental pollution with pesticides are acute. In this regard, the study and assessment of introduced grape varieties in different growing zones can facilitate the task of re-assortment and bring success to breeding programs. The purpose of the research is assessment of the prospects of cultivation in a non-covering culture with minimal protection against diseases of the Canadian table grape variety Vineland 68042, Vitis interspecific crossing on the basis of variety study and assessment of agrobiological, uvological, economically valuable traits. The variety study was carried out in 2010-2020 at the vineyard of the Experimental Field All-Russian Research Institute named after Ya. I. Potapenko for Viticulture and Winemaking Branch of Federal State Budget Scientific Institution FRARC, Novocherkassk, Rostov region. Vineyards not irrigated, not covered, grafted, rootstock Kober 5BB, 3 x 1.5 m planting scheme, horizontal bilateral cordon training system. Grape variety Vineland 68042 on totality of positive parameters (high winter hardiness, cold hardy resistance, powdery mildew resistance, yield, crop quality) can be of interest for cultivation in a non-covering crop with minimal chemical protection against diseases, as well as for use in breeding programs as a source of group resistance to diseases and frost. The variety has large clusters and berries, well sugar content in grape berries, and has a nice appearance. Degustation assessment of fresh grapes is 8.1 points. Vineland 68042 over the years of research has established itself as highly resistant to powdery mildew, grey mold Botrytis cinerea, medium resistant to mildew, resistant to the leaf form of phylloxera. The drawbacks of this grape variety include the tendency to overload the bushes with the yield.