The high yield potential of winter wheats cannot be realized due to disease pressure under field conditions. One of the most harmful of such diseases is stem rust, hence the constant search for sources of resistance and the development of new varieties resistant to stem rust is of great relevance. This study deals with the identification of stem rust resistance genes in a collection of winter wheats grown in Southern Russia. This genepool has not been studied yet. A total of 620 samples of winter soft wheat from various ecological and geographical zones were tested under field conditions. To identify the specific genes or alleles responsible for resistance, all samples were genotyped using PCR. As a result, the groups of resistant samples, carrying the Sr2, Sr31, Sr38 and Sr44 genes in various combinations, were identified. Most of the stem rust resistance was provided by the presence of the effective Sr44 gene. This information can be used in the future breeding work for stem rust resistance.

Nowadays in Russia and in the world, the problem of improving food security is becoming more and more urgent. One of the main crops grown worldwide is winter bread wheat. Varieties resistant to main leaf diseases can produce large grain yields. Thus, the study and identification of resistance genes are of great importance. The purpose of the current work was to estimate the gene pool of winter bread wheat from the CIMMYT collection (Mexico) according to the age brown rust Lr 34 resistance gene. In the study of collection samples, there have been used such methods as DNA extraction using CTAB, PCR, electrophoresis on agarose gels. As a result of the study, there has been identified a presence of a functional allele of the Lr 34 gene in 146 winter bread wheat samples out of 411 studied ones (sets 20th IWWYT-SA, 21th IWWYT-IRR, 25th FAWWON-IRR, 25th FAWWON-SA). There have been identified three samples with a heterozygous allelic state of the Lr 34 gene. There have been identified 232 samples with the non-functional Lr 34 gene allele. 30 winter bread wheat samples had no amplification of DNA fragments with the molecular marker csLV34, which means a significant microsatellite sequence variability for which the molecular marker was developed in their genotype. 121 out of 146 winter bread wheat samples with the functional brown rust Lr 34 resistance gene showed resistance in field conditions and in the infectious plots. The rest 25 samples with the Lr 34 gene belonged to the group of moderately resistant ones in the infectious plots. The identified 121 CIMMYT collection winter bread wheat varieties, with the Lr 34 gene possessing a resistant type of pathogen damage response (for example, 9919, 9921, 9928, 9809, 9811, 9812, 23, 24, 30, 262, 265, 266, etc.) have been recommended for use in leaf rust resistance pyramiding in future breeding programs.

One of the main problems in most of the world rice-growing regions is soil salinity. Rice is considered a saline sensitive crop, especially at the early stages of development and in the period of maturity. In the Rostov region, rice is grown in the south-eastern parts, where there are currently difficulties with the operation of the existing reclamation facilities. The problem of saline soils for this region is especially urgent, since a significant part of the arable lands has alkali complexes. In order to return the saline lands into exploitation, it is necessary to develop salt tolerant varieties, which, under crop rotation and maintenance, can contribute to soil desalinization. Due to the difficulty of determining salt tolerance only by estimating the phenotype, it is necessary to use molecular markers associated with this trait. Thus, the purpose of the current work was to identify one of the main Saltol QTL in breeding rice samples of the eighth generation (F8) obtained from hybridizing the donor variety NSYC Rc106 with Russian varieties. For that purpose, there have been used such marker-assisted selection methods as DNA isolation, polymerase chain reaction (PCR), electrophoresis on 2% agarose gels, gels’ coloring in ethidium bromide solution, photography in ultraviolet light and evaluation of the obtained electrophoregrams. As a result of the study of 398 breeding rice samples, there have been identified 67 samples with the functional allele of Saltol QTL (6865/3, 6874/2, Don 7343/4, Don 7343/5, Don 7343/6, Don 7343/7, Don 7343/8, Don 7343/9, Don 7343/10, Don 7337/1, Don 7337/3, Don 7337/4, Don 7337/5, Don 7337/6, Don 7337/7, Don 7337/8, etc.). There have been recommended to use these samples in the further breeding process in order to develop new salinity resistant rice varieties.