Types of biologically active substances, methods of their application as factors of increasing resistance of varieties of various potatoes in an effort to realize greater productivity when exposed to pathogenic organisms

All countries in the world strive not to repeat the potato famine of Ireland. Potatoes infect more than 100 pathogens, one of the most serious is late blight. In the world, the average loss of potato yield from late blight is 10-15% per year. This article briefly discusses various safe, effective and environmentally friendly methods of preventing and controlling late blight of potatoes.

The performance of the distribution and use of improved varieties of rice in West Java Province

West Java Province is one of the centers of rice production in Indonesia. The use of improved varieties continues to be pursued to support the increase in production. This study aims to analyze the performance and problems of distribution and the use of improved varieties in rice farming. The study was conducted in Majalengka and Cianjur Districts in 2020. The study sample consisted of 60 rice farmers and research-related institutions. Data analysis was carried out quantitatively by calculating the percentage of the distribution area and qualitatively descriptive. The results of the study show that in Cianjur District, from a total distribution area of 154,075 ha (in 2019), the distribution area of Ciherang and Mekongga varieties is 36.46% and 35.88%, respectively. While in Majalengka District, on the contrary, from the total area of 127,957 ha, the distribution of new improved varieties was more dominant, namely for Inpari 32 and Inpari 43 at 67.25% and 7.28%, respectively. Problems faced in the spread of new improved rice varieties include limited availability of seeds, limited demonstration plot activities, and resistance of varieties to pests and diseases. In rice farming activities in the study area, new high-yielding varieties produce relatively higher productivity compared to old improved varieties. In order to increase the spread of new improved varieties of rice, it is necessary to provide adequate seed support, description of the improvedity of improved seeds, demonstration plots, as well as support for government policies and programs for the development of new improved varieties.

Winter Resistance Of Winter Wheat Under Extreme Conditions

The article discusses the issue of frost resistance of varieties and samples of winter wheat sown at different depths, in the extreme conditions of Karakalpakstan. Both a decrease and an excessive deepening of sowing leads to a significant decrease in their resistance to low temperatures, which negatively affects their subsequent survival in the spring-summer period. On the basis of the data, 2 varieties were selected, they turned out to be frost-resistant and differed in good yield and other valuable traits in comparison with the zoned varieties. They were transferred to the State Commission for Variety Testing of Agricultural Crops, under the name "Chimbay" and "Aral".

BREEDING SOURCE MATERIAL OF TABLE CARROT RESISTANT TO EARLY BLIGHT ON AN ARTIFICIAL INFECTIOUS BACKGROUND

The paper presents the results of an immunological assessment of the lesion of table carrot varieties by Alternaria on an artificial infectious background in the conditions of the Moscow region in 2011–2019. To carry out visual assessments of the resistance of varieties, seeds were sown on an artificial infectious soil background of A. radicina (root confinement), additionally with subsequent spraying of plants with a spore suspension of A. dauci (leaf confinement). The studied varietal material of table carrots was divided into groups depending on the resistance – susceptibility range. The studies were based on successive selections of resistant plants (genotypes) over 6–8 years, even with a minimal number of them. As a result of four cycles of selection against an artificial infectious background of genotypes (plants) at different stages of ontogenesis, an increase in resistance was noticed. Each subsequent selection was characterized not only by the number of relatively resistant plants in the studied variety populations increased, but also the decreased average score of their lesion. Based on this, the authors have identified the breeding material of table carrots with high resistance to alternariosis.

Immunological variability of rice varieties depending on growing conditions

Blast (causative agent Pyriculariaoryzae Cavara) plays an important role among economically important, dangerous and harmful rice diseases of rice in all rice-growing countries, including Russia. The problem of resistance of rice plants to disease is one of the main problems in modern breeding in most countries. Intensification of rice cultivation creates a favorable microclimate in the sowing agrocenosis for the development of blast disease and leads to an increase in its harmfulness. The varieties quickly lose their resistance to new races of the pathogen, due to high spontaneous variability of the M. grisea fungus, its field populations are usually represented by a mixture of races with different virulence and aggressiveness, outstripping the evolution of the host plant. The nature of the blast manifestation depends on the agroclimatic conditions and genotype. The article presents the results of research at experimental and production plots of Federal Scientific Rice Centre (FSC of Rice) and Elite Seed-Production Experimental Statation Krasnaya (ESPES Krasnaya). It has been shown that a clear differentiation of rice varieties in terms of blast resistance and yielding properties is possible only when certain (provocative) conditions are created that contribute to the manifestation of their genetic potential, while the blast resistance of varieties cannot be provided only by the introduction of one gene of racespecific resistance. A close negative relationship was obtained between the yield and the intensity of blast disease on two backgrounds of mineral nutrition: N-1 - r = -0.93; N-2 - r = -0.95. The determination coefficients showed that in 86.8 - 90.1% of cases, the yield is due to the intensity ofblast development on the crops of the studied rice varieties.

Diseases of perennial bean grasses in Western Siberia

The directions and results of many years of research on the development and prevalence of diseases on perennial leguminous grasses (meadow clover, pannonian clover, sainfoin, sowing alfalfa) in Western Siberia are presented. A whole range of diseases was revealed, the intensity of development, which depends on weather conditions, resistance of varieties, plant age, etc.

SEARCH FOR DONORS OF RESISTANCE TO PATHOGENS AND PESTS OF POTATOES

Представлены данные о ракоустойчивости ис- следуемых сортов. Выделены устойчивые сорта к золоти- стой картофельной нематоде. Дана полевая оценка устой- чивости сортов к фитофторе, вирусным болезням.Выделены группы сортов по скороспелости, урожайности. Рекомендова- но использовать изученные сорта коллекции в насыщающих скрещиваниях. The data on the cancer resistance of the studied varieties are presented. Resistant varieties to the golden potato nematode have been identifi ed. A fi eld assessment of the resistance of varieties to late blight and viral diseases is given. The groups of varieties were selected for precocity, productivity. It is recommended to use the studied variety collections in saturating crosses.

Loci that determine long-term resistance to blast of Russian rice varieties

In all rice-growing countries, including Russia, among the economically important, dangerous and harmful diseases of rice, the main role is played blast (pathogen Pyricularia oryzae Cavara). The problem of resistance of rice plants to disease is one of the main problems in modern breeding in most countries. The most effective way to protect rice from blast is using resistant varieties created with marker assistant selection (MAS). The article presents data on chromosomal regions that provide long-term resistance of varieties to pathogen in Russia. The groups of stable and unstable samples significantly differed in the presence of polymorphic loci on the fifth, sixth, eighth, ninth and second chromosomes, which reduces the complexity of evaluating selection material due to the primary screening of gene plasms by variability of resistance loci in the identified chromosomal regions.