Leaf rust, caused by Puccinia triticina (Ptr), is a significant disease of spring wheat spread in Kazakhstan. The development of resistant cultivars importantly requires the effective use of leaf rust resistance genes. This study aims to: (i) determine variation in Ptr population using races from the East Kazakhstan, Akmola, and Almaty regions of Kazakhstan; (ii) examine resistance during seedling and adult plant stages; and (iii) identify the sources of Lr resistance genes among the spring wheat collection using molecular markers. Analysis of a mixed population of Ptr identified 25 distinct pathotypes. Analysis of these pathotypes using 16 Thatcher lines that are near-isogenic for leaf rust resistance genes (Lr) showed different virulence patterns, ranging from least virulent “CJF/B” and “JCL/G” to highly virulent “TKT/Q”. Most of the pathotypes were avirulent to Lr9, Lr19, Lr24, and Lr25 and virulent to Lr1, Lr2a, Lr3ka, Lr11, and Lr30. The Ptr population in Kazakhstan is diverse, as indicated by the range of virulence observed in five different races analyzed in this study. The number of genotypes showed high levels of seedling resistance to each of the five Ptr races, thus confirming genotypic diversity. Two genotypes, Stepnaya 62 and Omskaya 37, were highly resistant to almost all five tested Ptr pathotypes. Stepnaya 62, Omskaya 37, Avangard, Kazakhstanskaya rannespelaya, and Kazakhstanskaya 25 were identified as the most stable genotypes for seedling resistance. However, most of the varieties from Kazakhstan were susceptible in the seedling stage. Molecular screening of these genotypes showed contrasting differences in the genes frequencies. Among the 30 entries, 22 carried leaf rust resistance gene Lr1, and two had Lr9 and Lr68. Lr10 and Lr28 were found in three and four cultivars, respectively. Lr19 was detected in Omskaya 37. Two single cultivars separately carried Lr26 and Lr34, while Lr37 was not detected in any genotypes within this study. Field evaluation demonstrated that the most frequent Lr1 gene is ineffective. Kazakhstanskaya 19 and Omskaya 37 had the highest number of resistance genes: three and four Lr genes, respectively. Two gene combinations (Lr1, Lr68) were detected in Erythrospermum 35 and Astana. The result obtained may assist breeders in incorporating effective Lr genes into new cultivars and developing cultivars resistant to leaf rust.

Leaf rust (LR) is the most widespread disease of common wheat worldwide. In order to evaluate leaf rust resistance, 70 uncharacterized wheat cultivars and promising lines with unknown leaf rust resistance genes (Lr genes) were exposed to Kazakhstani Puccinia triticina (Pt) races at the seedling stage. Field tests were performed to characterize leaf rust responses at the adult plant growth stage in the 2020–2021 and 2021–2022 cropping seasons. The wheat collection showed phenotypic diversity when tested with two virulent races of Pt. Thirteen wheat genotypes (18.6%) showed high resistance at both seedling and adult plant stages. In most cases, breeding material originating from international nurseries showed higher resistance to LR. Nine Lr genes, viz. Lr9, Lr10, Lr19, Lr26, Lr28, Lr34, Lr37, Lr46, and Lr68, either singly or in combination, were identified in 47 genotypes. Known Lr genes were not detected in the remaining 23 genotypes. The most commonly identified resistance genes were Lr37 (17 cultivars), Lr34 (16 cultivars), and Lr46 (10 cultivars), while Lr19, Lr68, Lr26, and Lr28 were the least frequent. Four Lr genes were identified in Keremet and Hisorok, followed by three Lr genes in Aliya, Rasad, Reke, Mataj, Egana and Almaly/Obri. The molecular screening revealed twenty-nine carriers of a single Lr gene, ten carriers of two genes, six carriers of three genes, and two carriers of four genes. Most of these accessions showed a high and moderate level of APR (Adult plant resistance) and may be utilized for the incorporation of Lr genes in well-adapted wheat cultivars. The most effective combination was Lr37, Lr34, and Lr68, the carriers of which were characterized by a low disease susceptibility index. The obtained results will facilitate breeding programs for wheat resistance in Kazakhstan.

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.

Болезни сельскохозяйственных культур оказывают значительное влияние на урожайность и качество сельскохозяйственных культур во всем мире. На протяжении десятилетий угрозы со стороны болезней и вредителей сельскохозяйственных культур становятся все более серьезными в контексте глобального изменения климата, что создает проблему для нашего производства продуктов питания. В последние годы отмечаются нарастающее распространение и вредоносность желтой ржавчины в Казахстане. Большинство коммерческих сортов пшеницы, выращиваемых в настоящее время в Казахстане, по-прежнему восприимчивы к ржавчинным заболеваниям. Целью исследования является мониторинг развития желтой ржавчины и идентификация новых источников устойчивость к Puccinia striiformis Westend f. sp. tritici с использованием современных генетико-селекционных методов. По результатам мониторинга распространение и развитие желтой ржавчины было на среднем уровне (48-52%). Фитопатологический скрининг выявил 57 образцов озимой пшеницы (76,0 %) с иммунным типом реакции к желтой ржавчине. Идентифицированы 22 перспективных образца, которые проявили устойчивый и умеренно-устойчивый тип реакции к болезням и характеризуются присутствием нескольких генов устойчивсти. По результатам этого исследования отобранные перспективные линии озимой пшеницы представляют интерес для программы селекции пшеницы на устойчивость к желтой ржавчине.