Burak Özdemir

Drought stress is a major constraint limiting bread wheat productivity in semi-arid regions, where improved root system architecture is increasingly recognized as a key component of climate resilience. However, it remains unclear whether deep rooting is primarily a genetically determined trait or a plastic response induced by drought stress. This study tested the hypothesis that genotypic background exerts a stronger influence on deep rooting patterns than water deficit itself in bread wheat. Nine genotypes, including seven locally adapted landraces from the Van Lake Basin and two standard cultivars, were grown under controlled greenhouse conditions under well-watered and drought treatments, and root distribution was quantified at three soil depths (0–30, 30–60, and 60–100 cm). Deep root index was not significantly affected by water treatment alone, whereas genotype and genotype × water interaction effects were highly significant, indicating a strong genotype-dependent pattern of root depth allocation. Genotypes showed contrasting drought responses: Bitlis 1–4 increased deep root allocation from 39.8% to 53.1% under drought, while Bitlis 9–1 declined from 44.3% to 32.1%. Associations between root traits and grain yield were weak, suggesting that root system size alone is insufficient to explain drought adaptation. Overall, the results demonstrate that deep rooting in bread wheat is predominantly genotype-dependent rather than uniformly drought-induced. These findings identify promising germplasm with genotype-specific root responses under drought from the Van Lake Basin and provide a basis for integrating root distribution traits into breeding programs aimed at improving wheat performance under water-limited environments.

Wheat landraces are valuable genetic resources for improving crop adaptation, resilience, and sustainability under changing environmental conditions. However, despite the increasing number of studies, a systematic evaluation of global research trends in this field remains limited. A total of 1,774 publications indexed in the Web of Science Core Collection between 2000 and 2025 were analyzed using VOSviewer to assess publication trends, citation structures, keyword co-occurrence patterns, and international collaboration networks. The results showed a significant increase in research output, particularly after 2014, indicating growing scientific interest in wheat genetic resources. Keyword analysis revealed that studies are mainly concentrated on genetic diversity, genomics, and major wheat species such as Triticum aestivum and durum wheat. Citation and collaboration analyses identified the United States, China, and Israel as leading contributors, supported by strong international research networks. In conclusion, wheat landrace research has evolved into a rapidly expanding and collaborative scientific field. Strengthening the conservation of genetic resources and enhancing international collaboration will be critical for advancing sustainable agricultural development.

Aleppo oak (Quercus infectoria) is among the most industrially and ecologically significant oak species, valued for its medicinal properties and considerable genetic importance. Cytogenetic analysis provides critical insight into evolutionary history, interspecific relationships, and karyotypic differentiation. This study investigated the chromosomal architecture and karyotypic diversity of five natural populations of this species in western Iran (Sardasht, Oramanat, Baneh, Paveh, and Marivan) using actively dividing root meristems and a high-resolution image-based cytogenetic system. All examined cells displayed a basic chromosome number of x = 12 and a diploid condition, and chromosome lengths ranged from 0.90 to 2.12 µm. ANOVA and mean comparisons of five chromosomal parameters (Long Arm, Short Arm and Total Length, Arm Ratio, and Centromeric Index) revealed significant interpopulation differences in chromosome length and arm dimensions. All populations shared the karyotype formula 12 m and were classified into Stebbins’ Category B, indicating a moderately symmetrical, relatively primitive cytogenetic structure. Principal component analysis reduced the dataset to two major axes explaining 99.93% of the total variance, predominantly influenced by SA and TL on PC1 and by LA, AR, and CI on PC2. Hierarchical clustering grouped the populations into three distinct lineages, with Sardasht–Oramanat–Baneh showing the greatest divergence. Biplot vector patterns further clarified trait correlations, highlighting genomic structuring and potential breeding utility.

Wheat landraces are considered a valuable resource of potential phenotypic variation that could be used in germplasm improvement. Here, we examined 588 local wheat genotypes collected from farmers’ fields at 127 locations around Van Lake Basin and evaluated the morphological diversity and trait associations using Multidimensional Scaling Analysis. Spike and yield traits were measured and scored according to the UPOV and ICARDA phenotypic characterization criteria. Multidimensional Scaling Analysis divided the wheat samples into four main groups based on the number of spikelets (NOS), number of fertile spikelets (NFS), thousand-grain weight (TGW), and number of seeds per spike (NSS) and indicated a strong correlation between NOS and NFS. Furthermore, the analysis revealed that the glume and awn color of most of the genotypes was black, and they were within the locally known Karakılçık group. Only two genotypes were excluded from the Karakılçık group; No. 231 was within the Geverik local wheat group, and genotype No. 579 was found to be Tir. The Hevidik and Kirik groups had the same spike color, but the Hevidik group had spikes similar to compactum wheat, whereas the Kirik group had larger spikes. Finally, genotype No. 57 varied from all other genotypes when all the measured traits were taken into consideration. Overall, the Van Lake Basin landraces combine broad similarity with meaningful phenotypic heterogeneity shaped by local environments and traditional on-farm selection. These findings provide practical cues for conservation efforts and for the use of landraces as valuable resources in future wheat breeding programs.

Arbuscular mycorrhizal fungi (AMF) play a pivotal role in sustainable agriculture by enhancing nutrient efficiency and reducing the dependence on synthetic fertilizers. Developing these sustainable, effective products requires knowledge of the target plant and its associated microbial communities in the production landscape of interest. This study focused on AMF populations associated with Tir wheat in six main locations of Türkiye’s Van Lake Basin. The Erçek-Özalp-Saray region exhibited the highest organic matter values. Higher available phosphorous contents were found for Erciş-Patnos and Muradiye. The Erciş-Patnos region exhibited the highest AMF density (120 spores/10 g soil) and frequency (75%), while the lowest AMF density (45 spores/10 g soil) was recorded in Muradiye. Sand contents correlated positively with spore number and mycorrhizal frequency and negatively with silt and clay. Based on these results, Erciş-Patnos was elected as the best location for the isolation of AMF spores suitable for the development of microbial-based tools for Tir wheat cultivation. These results are very important in the current context of climate change, which mandates the use of low-impact environmental strategies. Further research should explore the interactions of AMFs with other microorganisms to optimize their ecological benefits. However, the results of this study provide a valuable basis for future investigations of AMF-based products for use in sustainable Tir wheat cultivation.

Discovering the variation among genotypes is an important criterion for selecting the suitable cultivar for a certain environment. The study aimed to explore the genetic variation among 17 genotypes of barley based on grain yield and some related traits. Plants were grown under field grown conditions in the 2019-2020 and 2020-2021 growing seasons, and plant height (PH), spike per square meter (SSM), spike length (SL), spikelets per spike (NSS), seed per spike (SPS), biological yield (BY), grain yield (GY), and thousand grain weight (TGW) were measured. Results indicated that PH ranged (51.7 to 81.33 cm) and (58.20 to 79.90 cm), SSM (374 to 582) and (418 to 701), SL (7.10 to 9.63 cm) and (6.87 to 9.13 cm), NSS (9 to 15) and (8 to 17), SPS (21 to 49) and (21 to 51), BY (3466.7 to 5905.3 kg h-1) and (3731.7 to 6080 kg h-1), GY (1442 to 2192 kg h-1) and (811.8 to 1763.7 kg h-1), TGW (34 to 55.67 g) and (33.47 to 52.63 g) for the first and second year of experiment respectively. The advanced lines measurement values were higher in the second year of the experiment. It can be concluded that the advanced lines Anka-08 and Anka-11 are promising in most of the parameters. Some of the old and new cultivars still preserve their yield potential.