Evaluation of Disease Resistance in Wheat Genotypes for Organic Farming Under Kazakhstan Conditions

Molecular genetic analysis of potato genotypes for late blight resistance

Increasing crop yields and enhancing their adaptation to changing growing conditions are among the key strategies for ensuring food security. Potato is one of the most important food crops worldwide and is cultivated on all continents. Plant breeders play a crucial role in ensuring sustainable potato production by developing new resistant varieties with increased yield per hectare. Since the 1990s, genetics has played an increasingly important role in plant breeding through the introduction of DNA markers as indirect selection tools and for the assessment of genetic diversity. Today, genomics-based plant breeding approaches, such as marker-assisted selection (MAS) and genomic selection (GS), accelerate the breeding process for many major crops. The aim of this study was to identify genes conferring late blight resistance in 30 promising potato hybrids using DNA markers. Laboratory analyses for late blight resistance were conducted at the Laboratory of Molecular Genetic Research of Agricultural Plants at the Vladikavkaz Scientific Center of the Russian Academy of Sciences. The breeding material was preliminarily evaluated under field conditions in accordance with the recommendations for potato breeding programs. Genomic DNA was extracted from potato leaves during the flowering period using the CTAB method. For molecular genetic analysis of late blight resistance, the following R-gene molecular markers were used: R1–1250, R3a-1380, and R3b-378. The molecular genetic analysis revealed the presence of all three markers R1–1250, R3a-1380, and R3b-378. They were identified in five different potato hybrids. These hybrids included: 3375–1 (Tiras × Breeze), 3403–2 (Arizona × Fritella), 3341–2 (Innovator × Mirage), 3352–1 (Kolette × Mirage), and 3352–4 (Kolette × Mirage). The presence of all three genes indicates a high degree of late blight resistance. Thus, the identification of potato genotypes using molecular markers facilitates the acceleration of the breeding process for developming new resistant potato varieties.

Genetic Variability of Wheat Collection Selected with Respect to the Resistance to Leaf and Stem Rusts

Wheat (Triticum aestivum L.) is an economically important cereal crop. Its genetic diversity is a prerequisite for successful breeding for resistance to leaf and stem rust, as well as for other important traits. Therefore, the main objective of the study was to determine the level of genetic diversity of a file of 185 wheat accessions chosen to represent a wide range of resistance levels to leaf and stem rusts. They were evaluated at two locations in three years (2023–2025) for leaf and stem rust resistance by means of visual evaluation and fungus content using real-time PCR. BLUP values were then computed from these multi-environmental data. In addition, data on other traits such as heading time, plant height, and grain quality were collected. In the PCA, grain quality variables represented the first factor, explaining 41% of the total variability. Rust resistance was mainly associated with the second and the third factor. Population analysis revealed primary two (K = 2) and secondary six (K = 6) clusters, computed by using 13,274 DArT markers. The correlation between genotype and phenotype data was high (R = 0.89) when all traits were analyzed, and lower (R = 0.58) when only leaf and stem rust resistance variables were considered. Genetic diversity was also studied through an association analysis between markers and phenotypic traits using GLMs and MLMs. As a result, 300 statistically significant marker-trait associations (MTAs) were identified (p ≤ 3.77 × 10−6). Of these MTAs, 180 were associated with rust resistance variables and 120 with other traits. A BLAST search of rust resistance MTAs identified 128 putative genes; 47 of them can be taken for candidate genes related to fungal resistance. The results show that association analysis can help to explain the genetic diversity of selected wheat accessions, and that leaf and stem rust resistance are complex traits involving many non-specific resistance genes.

Phenotypic Screening and Statistical Validation of an Evaluation Scale for Fusarium Dry Rot Resistance in Potato Germplasm

Potato is a globally important staple, but postharvest diseases such as dry rot, caused by Fusarium spp., threaten production and lead to major economic losses and food safety risks. Limited resistant cultivars highlight the need for phenotypic screening and integration with genomic tools to improve resistance and breeding efficiency. A total of 336 potato genotypes, including 295 commercial varieties and 41 breeding clones, were evaluated under post-harvest conditions following artificial inoculation. Tubers were inoculated with Fusarium sambucinum, and lesion penetration measured to classify susceptibility. Overall, this study provides one of the most comprehensive phenotypic evaluations of dry rot resistance in potato germplasm to date. While no variety was fully resistant, the identification of both moderately susceptible and highly susceptible cultivars offers valuable insights for breeding programs and contributes to the development of more resilient potato production and storage systems. In addition, this phenotypic screening can be integrated with genomic tools to accelerate breeding for improved resistance and postharvest performance.

Identification of stripe rust resistance loci in Gansu wheat landraces using genome-wide association analysis

A successful stacking of multiple biotic stress resistance in rice facilitated by genes and precision breeding tools

Genetic improvement of rice for biotic stress is a major and continuous breeding objective owing to changing pest and disease scenarios. In response to climate change, an outbreak of new pathotypes and biotypes results in huge yield loss which directly impacts the economic stability and food security. The development of varieties with multiple resistance genes for a particular disease is the most effective approach to the combating mechanism against evolving pathogens and insects. Multiple resistance genes against blast (Pi54), bacterial leaf blight (xa5, xa13, Xa21), and brown plant hopper (Bph17, Bph3, bph2) were pyramided through marker-assisted forward breeding by attempting multiple crosses involving six parental lines. The F4 lines were screened and the resistant lines were further reconfirmed at the F5 stage through precise phenotyping and also by genotyping with trait-specific markers. Finally, the selected lines were evaluated for the agronomic performance. Four lines were selected from the population which carrying seven resistance genes against BL, BB, BPH with superior agronomic performance. Another line, x21302-239, harboring all the resistant genes and showing a resistant response in screening experiments for all three stresses, with marginal agronomic performance (single-plant yield: 33 g), can be utilized as a desirable donor to develop elite rice cultivars with multiple biotic stress resistance. Homozygous genetic background is more favorable for epidemic outbreak in a short period of time in comparison with the population of multiple genetic background. Since this complex genetic background disturbs the infectious cycle of the pathogen. So that a variety or a hybrid which developed from multiple parental lines are notable for their durable resistance than the monogenic resistance variety.

Molecular-Marker Integration for Crop Disease-Resistance Screening and Trait Identification in Agricultural Biotechnology Applications

A comprehensive analysis of the methodological, theoretical, and practical frameworks underlying molecular-marker applications in modern plant breeding is provided, offering a thorough perspective on how molecular biotechnology can be optimized to ensure future global food security.