Detection and Heritability of Genes Conferring Resistance to Potato Pests and Viruses in Hybrid Potato Progeny (Solanum tuberosum L.)

Genetics and Resistance / Génétique et Résistance High-confidence genomic regions associated with leaf stripe and spot blotch resistance in barley

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.

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.

Detection of potato virus Y resistance gene markers in the potato germоplasm of Kazakhstan

Abstract The objective of this study was to screen Kazakhstan-developed potato varieties for DNA markers linked to genes conferring extreme resistance to potato virus Y (PVY) and to evaluate their resistance to PVY infection. The object of the study was the biomaterial from 36 potato varieties provided by Kazakh Scientific Research Institute of Fruit and Vegetable Growing Limited Liability Partnership and Kostanay Scientific Research Institute of Agriculture Limited Liability Partnership. To determine the level of resistance to potato virus Y in the samples, plants were artificially infected with the virus in open ground and under controlled phytotron conditions. The assessment was carried out by visual observation of symptoms on inoculated potato plants, as by enzyme-linked immunosorbent assay. 38% of the varieties have shown extreme resistance to potato virus Y, 16% - Medium resistance (MR), 8% - Susceptible (S) and 41 % - High sensitivity (HS). The results obtained can be used in breeding programs to create virus-resistant potato varieties, as well as in fundamental research on the mechanisms of potato resistance to potato virus Y.

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.

Harnessing wild peanut genetic resources for field resistance to tomato spotted wilt and late leaf spot diseases.

Tomato spotted wilt virus (TSWV) and late leaf spot (LLS) are among the major constraints to peanut production. Cultivated peanut has narrow genetic bases and lacks strong sources of resistance. Wild species, on the other hand, harbor diverse and strong resistances to multiple pathogens. In this study, we evaluated advanced breeding lines carrying introgressions from multiple wild Arachis species (A. stenosperma, A. batizocoi, A. valida, and A. cardenasii) across three contrasting field environments and experimental designs in Georgia, USA using complementary incidence- and severity-based phenotyping. Genotype effects were highly significant for both diseases. Several wild-derived lines -particularly those from A. stenosperma ancestry- showed strong and stable TSWV resistance across environments. Interestingly, some lines lacking detectable wild segments also showed high resistance to TSWV, suggesting cryptic or undetected introgressions. LLS resistance was primarily associated with the characteristic A. cardenasii segments on A02 and A03, and lines stacking these introgressions consistently outperformed both cultivated parents and Georgia-06G, the most popular cultivar in the USA. Correlations between TSWV and LLS responses were weak, confirming genetic independence and emphasizing the need to screen both traits. A small subset of lines combined resistance to both diseases, and many also retained resistance loci to root-knot nematode (RKN), expanding their value as multi-trait donors. These findings demonstrate the power of wild introgression breeding for enhancing disease resistance and provide a foundation for deploying stacked alleles through marker-assisted and multi-environment selection.