Zymoseptoria tritici (Z. tritici) is the main threat to global food security; it is a fungal disease that presents one of the most serious threats to wheat crops, causing severe yield losses worldwide, including in Kazakhstan. The pathogen leads to crop losses reaching from 15 to 50%. The objectives of this study were to (1) evaluate a wheat collection for Z. tritici resistance during the adult plant and seedling growth stages, (2) identify the sources of resistance genes that provide resistance to Z. tritici using molecular markers linked to Stb genes, and (3) identify potentially useful resistant wheat genotypes among cultivars and advanced breeding lines. This study evaluated 60 winter and spring wheat genotypes for Z. tritici resistance. According to the field reactions, 22 entries (35.7%) showed ≤10% disease severity in both years. The resistant reaction to a mix of Z. tritici isolates in the seedling stage was associated with adult plant resistance to disease in four wheat entries. The resistance of Rosinka 3 was due to the presence of Stb8; Omskaya 18 showed an immune reaction in the field and a moderately susceptible reaction in the seedling stage, possibly provided by a combination of the Stb7 and Stb2 genes. The high resistance in both the adult and seedling stages of Omskaya 29 and KR11-03 was due to the Stb4 and Stb2 genes and, possibly, due to the presence of unknown genes. A linked marker analysis revealed the presence of several Stb genes. The proportion of wheat entries with Stb genes was quite high at twenty-seven of the genotypes tested (45.0%), including four from Kazakhstan, nine from Russia, nine from the CIMMYT-ICARDA-IWWIP program, and five from the CIMMYT-SEPTMON nursery. Among the sixty entries, ten (16.7%) carried the resistance genes Stb2 and Stb8, and the gene Stb4 was found in seven cultivars (11.6%). Marker-assisted selection can be efficiently applied to develop wheat cultivars with effective Stb gene combinations that would directly assist in developing durable resistance in Kazakhstan. Resistant genotypes could also be used as improved parents in crossing programs to develop new wheat cultivars.

The walnut (Juglans regia L.) holds a significant position among Kazakhstan’s nut crops, both in terms of cultivation and consumption. Although genetic resources of walnut are accessible within the country, they remain underexplored, yet they represent a valuable foundation for breeding initiatives and the development of locally adapted varieties. Currently, a comprehensive genetic profile of these resources is lacking, which hampers their effective utilization. The aim of this research was to evaluate the genetic diversity within a collection of walnut accessions collected from the southern and southeastern regions of Kazakhstan, including Almaty and Turkestan regions. To achieve this, eight SSR molecular markers were employed, providing insights into the genetic structure and relationships among the germplasm. All markers exhibited a high degree of polymorphism, with the WGA276 locus standing out as the most informative, displaying the greatest number of alleles and a high Shannon diversity index. The average expected heterozygosity (He) was 0.704 and was significantly higher than the observed heterozygosity (Ho = 0.547), which was confirmed by t-test (t = −6.426, p < 0.05). The findings indicated substantial genetic variation and intra-population polymorphism: on average, 5.875 alleles per locus were identified, and the Shannon index was 1.444. The population from Turkestan region (population 1, Sairam-Ugam) demonstrated the highest levels of diversity. Analyses of genetic structure, conducted through STRUCTURE, PCoA, and UPGMA methods, confirmed the existence of two genetically distinct groups exhibiting considerable diversity. Future research should focus on conserving the highly diverse populations in the Turkestan region to facilitate the development of stress-tolerant varieties. These findings highlight the importance of conserving and harnessing the genetic resources of Kazakhstan’s J. regia populations for future breeding efforts.

Wheat breeding plays a pivotal role in ensuring food security, as wheat ranks among the most demanded and widely cultivated cereal crops globally. This article presents a comprehensive analysis of a collection of wheat breeding lines, utilizing agronomic, phytopathological parameters, and molecular-genetic screening. The main traits are described in detail, including days to heading (ranging from 21 to 221 days, predominantly mid-season lines), plant height (92–134 cm), and NDVI biomass index (51–72.5), with emphasis on promising lines exhibiting high NDVI values (>70). Evaluation for yellow rust resistance identified seven immune and five moderately susceptible lines; approximately 60% of the genotypes displayed immunity to the causal agent of Pyrenophora tritici-repentis. Resistance levels were classified according to the area under the disease progress curve (AUDPC): resistant (AUDPC 400) groups. Molecular screening revealed the presence of the recessive tsn1 allele, associated with resistance to PtrToxA, in 18 lines (52.94%). Correlation analysis indicated mostly weak associations between agronomic traits and disease resistance, except for expected strong positive correlations among parameters related to a single disease. Statistical analysis demonstrated considerable variability and the presence of outliers in most traits, underscoring the necessity for robust analytical methods. The findings highlight the effectiveness of integrating conventional and modern assessment approaches for selecting promising wheat lines in breeding programs.

Walnut (Juglans regia L.) holds a significant position among Kazakhstan’s nut crops, both in terms of cultivation and consumption. Although genetic resources of walnut are accessible within the country, they remain underexplored, yet they represent a valuable foundation for breeding initiatives and the development of locally adapted varieties. Currently, a comprehensive genetic profile of these resources is laking, which hampers their effective utilization. The aim of this research was to evaluate the genetic diversity within a collection of walnut accessions collected from the southern and southeastern regions of Kazakhstan, including Almaty and Turkestan regions. To achieve this, eight SSR molecular markers were employed, providing insights into the genetic structure and relationships among the germplasm. All markers exhibited a high degree of polymorphism, with the WGA276 locus standing out as the most informative, displaying the greatest number of alleles and a high Shannon diversity index. The average expected heterozygosity (He) was 0.704, markedly higher than the observed heterozygosity (Ho), which was 0.547. The findings indicated substantial genetic variation and intra-population polymorphism: on average, 5.875 alleles per locus were identified, and the Shannon index was 1.444. The population from Turkestan region (population 1, Sairam-Ugam) demonstrated the highest levels of diversity. Analyses of genetic structure, conducted through STRUCTURE, PCoA, and UPGMA methods, confirmed the existence of two genetically distinct groups exhibiting considerable diversity. These findings highlight the importance of conserving and harnessing the genetic resources of Kazakhstan’s J. regia populations for future breeding efforts.

Tan spot of wheat, caused by the fungus Pyrenophora tritici-repentis (Ptr), is one of the most destructive foliar diseases of wheat worldwide and in Kazakhstan. Expansion of wheat plantings, the adoption of no-till methods, and the use of ineffective fungicides contribute to the accumulation of inoculum and the spread of the pathogen. Despite the important role of fungicides in plant protection, data on the susceptibility of Ptr populations in Kazakhstan are lacking. This study, for the first time, assessed the susceptibility of Ptr isolates from various regions of Kazakhstan to QoI and DMI fungicides. A predominance of genotypes associated with ToxA (82.9%) was found, with a limited distribution of ToxB (7.9%). Propiconazole demonstrated the highest efficacy, inhibiting mycelial growth by an average of 70.85%, followed by pyraclostrobin (69.04%), while azoxystrobin demonstrated lower efficacy (41.47%). Molecular analysis revealed the widespread prevalence of the G143A mutation in the cytochrome b gene, associated with resistance to the QoI fungicide. These results indicate the emergence of strobilurin resistance in Ptr populations in Kazakhstan and highlight the need for regular monitoring of fungicide susceptibility and the development of effective resistance management strategies.

Diseases caused by Bipolaris sorokiniana, expressed as leaf spot blotch (SB) and common root rot (CRR), continue to limit spring wheat production, particularly in dry regions where yield losses may reach 35–40%. This study evaluated resistance to SB and CRR in fifty spring wheat genotypes at both seedling and adult plant stages and identified genetic sources of resistance using molecular markers linked to the Sb1 and Sb2 genes. Field trials were conducted in 2023 and 2024 in the Aktobe region under natural infection, artificial inoculation, and a fungicide-treated background. Based on leaf spot blotch severity quantified as the area under the disease progress curve (leaf AUDPC) under natural infection, nine genotypes displayed stable resistance across both years, while fungicide-treated plots revealed twenty-three resistant genotypes in 2023 and eighteen in 2024. Artificial inoculation identified five resistant lines in 2023 and one in 2024. Resistance to common root rot (CRR) was assessed independently based on subcrown internode (SCI) browning at the adult plant stage. Seedling assays confirmed consistent resistance in six genotypes, all of which carried Sb1, Sb2, or their combination. In total, Sb genes were detected in thirty-six of the fifty accessions, including genotypes from Kazakhstan, Russia, and several other countries. The presence of Sb1 or Sb2 was associated with reduced disease severity, particularly at the seedling stage. These findings identify valuable germplasm for breeding wheat with improved resistance to B. sorokiniana in Kazakhstan.