Öner Canavar

Salinity is one of the most detrimental abiotic stresses, significantly impairing plant growth, nutrient balance, and productivity. In recent decades, nano

Corn is one of the most economically important cereal crops cultivated around the world, and understanding the proper mobilization and utilization of starches, sugars, pectin, and metabolites in seeds is crucial for enhancing effective germination and promoting the development of healthy seedlings. Salt stress hinders seed germination by limiting water uptake, damaging cell structures, disrupting key metabolic processes, and impairing the function of endosperm and embryo tissues. However, visual representations and imaging of biochemical changes in the tissues and cells of the embryo and endosperm within corn seeds during germination under salt stress have been limited in the literature. In this study, we aimed to compare the structural changes and visualize the biochemical alterations occurring within the seed tissues (i.e., the outermost layer of the corn seed, endosperm, and embryo) at 6, 24, 48, and 96 h during germination under non-stress control conditions (0 dS m⁻¹) and salt stress conditions (4 dS m⁻¹ and 8 dS m⁻¹) using light fluorescence and scanning electron microscopy (SEM). We observed that pores between the pericarp cells (epidermis), the outermost part of the seed, did not shrink or deform under salt stress. In contrast, under non-salt stress conditions, the intercellular spaces between the pericarp cells opened rapidly. This limited porosity in the outermost layer cells could lead to inadequate water absorption, significantly contributing to delayed or failed germination under salt stress. Starch, the primary storage carbohydrate found in the endosperm, decreased rapidly under non-salt stress conditions; however, starch degradation slowed under salt stress. Almost no starch grains were detected in the embryo or scutellum cells. Protein depletion in aleurone cells occurred rapidly during germination in the absence of salt stress but slowed as salt stress increased. We also observed that the movement of metabolites from the embryo to the root and shoot regions within the seed was slowed or diminished under saline conditions. Alterations in cellulose and tannins were observed during seed germination under both salt and non-salt stress conditions; however, the scutellum cell walls retained their structural integrity due to partial, localized degradation. During germination, endosperm cell walls became more distinct, with an increased presence of pectin and mucopolysaccharides. The shoot region, initially rich in proteins, sugars, tannins, and pectins, was also found in the mesocotyl cells and intercellular spaces. Visualizing these changes in seed structure throughout our study enhances our understanding of the adverse conditions.

This study evaluated the morphological, physiological, and biochemical responses of ten soybean (Glycine max L. Merrill) cultivars to three levels of salt stress (0, 3, and 6 dS m⁻¹) from seedling emergence to the V4 growth stage. Increasing salt concentrations significantly reduced plant height, fresh and dry weights, leaf area, relative water content, chlorophyll a, chlorophyll b, SPAD, and carotenoid levels. In contrast, relative membrane permeability (RMP), proline, and malondialdehyde (MDA) levels increased with salt stress. This study showed that there was a 0.821** positive correlation between salt stress and rmp with the increasing salt stress, besides the increasing leaf permeability significantly in the leaves of all cultivars had a negatively significant correlation relationship with other measured traits, because of oxidative membrane damage. Notably, cultivars with higher MDA and lower proline contents produced less biomass under stress, emphasizing the role of oxidative damage and limited osmoprotectant accumulation. These findings underline proline accumulation as a key indicator for selecting salt-tolerant genotypes and improving crop resilience in saline environments. Additionally, the variation in proline and MDA responses among cultivars suggests genotype-specific mechanisms of salt stress tolerance.

The study aimed to determine how the physiological responses of the sunflower (Helianthus annuus L.) plant were affected by prolonged drought stress, salinity stress, and boron application, as well as to assess the recovery dynamics following re‐watering. The experimental design included well‐watered (WW 80% watering), drought stress (DS, 20% watering) salinity stress (SS, 0 control and 13 dS m⁻¹), boron toxicity (Na₂O₅B₂O₃.10H₂O, at different doses of 0 and 8 mg L⁻¹) and re‐watering after a long‐term period of drought stress (24 days). The well‐irrigated (80% WW) treatment, which included all factors as a the non‐stressed control treatment during the experiment was carried out with five replications. Morphological, physiological and biochemical analyses of plants were measured at four time points: at the 10th and 24th days after the onset of the drought stress period and after re‐watering, at 2nd and 7th days following. The relative membrane permeability was increased and relative water content was decreased because drought and salinity stress limited water availability and caused an imbalance in the water status of the leaves and stem of the plant. Even though high levels of Na⁺ and Cl⁻ ions interfered with essential nutrient uptake under drought stress and boron application, Ca⁺² ion levels in the leaves significantly increased in the leaves of plants in areas treated with drought, salt, and boron after re‐watering. Extended or intense drought and salinity conditions harmed the phloem and xylem tissue cells of the stem by changing cell size and density, which in turn disrupted biochemical processes, including the functioning of water channels under challenging circumstances. Particularly under conditions of salt and drought stress, the vascular bundles in the plant stem were observed to either shrink significantly or assume an irregular shape. Long‐term drought reduced relative water content (RWC) values, resulting in plant dehydration and increased osmotic pressure (RMP) in leaf cells, further exacerbated by salinity and drought stress. The plant attempted to regain some of its characteristics in response to these severe stress conditions after re‐watering. However, 24 days after the long dry period, even if watering was re‐applied, the growth power of the plant was reduced due to the disturbance in membrane permeability as a result of excessive cell damage.

Undesirable coloring pigments in naturally colored fibers can affect their aesthetic and commercial value in the textile industry. In our green cotton breeding program, we identified a gene mutation that causes different colored fibers to form on a single seed. We investigated the expression patterns of flavonoid biosynthesis structural genes to understand the formation of these different colors between the chalazal and microphyll parts of the seed. Significant variations in gene expression levels were observed among the examined flavonoid genes, highlighting the complexity of flavonoid biosynthesis pathways in cotton seeds. In the green fibers on the microphyll part, lower expression levels of enzymes such as 4Cl (4-coumarate: CoA ligase), C4h (cinnamate 4-hydroxylase), F3h (flavone 3-hydroxylase), F3′5′h (flavonoid 3′5′-hydroxylase), Ans (anthocyanidin synthase), Anr (anthocyanidin reductase), and Ufgt (UDP-glucose: flavonoid 3-O-glucosyltransferase) were identified as potential factors influencing fiber coloration. Conversely, in the white fibers on the chalazal part, the expression levels of Chs (chalcone synthase) and Chı (chalcone isomerase) genes were lower than those in the microphyll part. This low expression is thought to be due to a mutation at the beginning of the phenylalanine pathway, preventing the formation of a green color in the white fibers on the chalazal part together with the low synthesis of the Chı gene. Understanding the molecular mechanisms behind these mutations is crucial for developing strategies to mitigate their effects and sustain the textile industry. The findings can inform cotton breeding programs to address unwanted coloration issues through genetic interventions, potentially enhancing the aesthetic and commercial value of naturally colored cotton fibers.

This study investigates the effects of nitrogen fertilization on the composition of confectionary sunflower seeds, including parameters such as oil content, alpha-tocopherol, sucrose, amino acids and fatty acid composition. Nitrogen fertilization, surprisingly, had no significant effect on sunflower oil content, with remarkable differences observed between the genotypes. The α-tocopherol content, an important antioxidant, displayed responses that were dependent on the genotype upon application of nitrogen. The Somon Beyazı genotype consistently demonstrated higher oil content compared to the Ahmet Bey genotype. In addition, both genotypes showed a decrease in α-tocopherol levels as the application of nitrogen increased. Sucrose content was higher in the Somon Beyazı genotype and decreased significantly with increasing nitrogen doses. Significant variations were observed in fatty acid compositions, further emphasizing the impact of genotype and nitrogen application. The study also revealed diverse amino acid profiles, with notable concentrations of glutamine and asparagine. This comprehensive study highlights the complex interaction between genotype and nitrogen fertilization and provides valuable insights for optimising sunflower seed production and quality. The results emphasise the significance of integrating both genetic factors and nutrient management practices into crop cultivation for improved agricultural outcomes.

Salinity stress poses a major challenge to plant growth and development, causing problems like osmotic stress, ion toxicity, and nutrient imbalances. These issues lead to reduced photosynthesis and early aging of plants. In this study, we explored the potential of potassium humate (Kh) and iron oxide nanoparticles (Fe (II,III) oxide-NPs) to help cotton plants (Gossypium hirsitum L.) cope with saline conditions. We examined various growth parameters such as plant height, leaf number, fresh and dry weights of leaves and roots, leaf area, chlorophyll content (SPAD values), and relative water content (RWC). Our findings showed that salinity stress significantly decreased plant height, leaf number, fresh leaf weight, dry leaf weight, leaf area, and RWC. However, the application of Fe (II,III) oxide-NPs and Kh helped mitigate these negative effects. Notably, the combination of Fe (II,III) oxide-NPs and Kh resulted in the highest plant height under saline conditions. Kh alone was particularly effective in increasing leaf number and fresh leaf weight, even under stress. In conclusion, both Fe (II,III) oxide NPs and Kh proved to be effective in enhancing cotton plant resilience to salinity stress, highlighting their potential use in sustainable agriculture in saline and arid regions. These insights can help develop strategies to improve plant growth and yield under challenging environmental conditions.

The impact of drought stress on productivity of cotton (Gossypium hirsutum L.) is a well‐known challenge in agricultural production, and concurrently, the question of whether using the same or different selection criteria in well‐watered and water‐deficit conditions to select drought‐tolerant cotton varieties remains unclear. This study aimed to comprehensively assess the single plant progeny lines within the F6 and F7 generations for determine response to DS and select the tolerant lines within the F7 generation. Single plant progeny rows were established, with the deficit water condition comprising 108 and 136 single plants for the F6 and F7 generations, respectively, and the WW condition consisting of 120 and 156 single plants for the F6 and F7 generations, respectively, with four blocks in Augmented experimental design. These progeny rows have length of 12 m, incorporate five control varieties (Karizma, Gloria, Carla, Candia and Claudia) to facilitate a comprehensive comparison. The study findings showed that fibre length, boll number and lint percentage were identified as the most crucial selection criteria under both WW and deficit irrigation conditions through principal component analysis. These indicators are highly beneficial for evaluating cotton's drought tolerance and screening potential drought‐tolerant lines under both irrigation scenarios. According to the decision tree analysis, FL and BN have emerged as the most critical decision‐making parameter in both irrigation conditions. Furthermore, the analysis revealed that each selection criterion has different impact in the comprehensive selection process. Also, as a result of all statistical analysis results and breeder observations, a total of 10 cotton lines were selected in the F7 generation. These selected genotypes hold promise for future cotton breeding programmes, providing an avenue to enhance drought tolerance and elevate cotton yield and productivity.Clinical Trial Registration: This study does not involve a clinical trial, and therefore, clinical trial registration is not applicable.

This study investigated the effects of salinity and K-humate concentrations on soybean germination. The findings contribute to our knowledge of soybean germination under salt stress and the potential use of potassium humate. The experiment was conducted in the laboratory of the Department of Field Crops at Adnan Menderes University, Turkey. Seeds were surface-sterilized and placed on filter paper in Petri dishes. Different concentrations of water (control), NaCl solution (3 dS m^-1), and K-humate solution were added. The experiment followed a factorial design with two factors and four replications. K-humate had a positive impact on germination rate. Significant differences were observed among control, salinity, and salinity * K-humate applications. Salinity reduced germination percentage. K-humate mitigated the negative effects of salinity, improving germination. These findings suggest the potential use of K-humate to enhance seedling establishment and overall plant productivity in salinity-affected environments.

Pamuk tarımında bitki gelişimi, çiçeklenme, tarak ve koza oluşumu bitki sıklığından önemli derecede etkilenmektedir. Bu çalışma, açık (Karayel) ve kloster (Lodos) koza dizilişine sahip iki farklı pamuk genotipinin beş farklı bitki yoğunluğunda (7,000 bitki/da, 14,000 bitki/da, 21,000 bitki/da, 28,000 bitki/da ve 35,000 bitki/da) bölünmüş parseller deneme desenine göre dört tekerrürlü olarak Aydın ili koşullarında, 2019 üretim sezonunda yürütülmüştür. Çalışmanın amacı; farklı bitki yoğunluklarının farklı bitki biomasına sahip pamuk çeşitlerinin verim, verim komponentleri ve lif kalite özellikleri üzerine etkilerini saptamak amacıyla yapılmıştır. Bitki yoğunluğunun artması (28,000 ve 35,000 bitki/da) ile bitki boyu, meyve dalı sayısı, odun dalı sayısı, tek koza ağırlığı, koza sayısı değerlerinde azalma; aksine ilk meyve dalının bulunduğu boğum sayısı, birinci el hasat oranı, ilk koza açma gün sayısı, lif inceliği değerlerinin arttığı tespit edilmiştir. Bitki yoğunluğunun, lif inceliği dışındaki diğer lif kalite özellikleri ve çırçır randımanı üzerine ise önemli bir etkisinin olmadığı belirlenmiştir. Açık ve kloster yapıya sahip pamuk çeşitlerinin farklı bitki yoğunluklarında kütlü verimi bakımından farklı tepkiler göstermiştir. Her iki çeşidin bitki sıklığı ortalamasına göre, en yüksek kütlü pamuk verimi (649.4 kg/da) ve lif verimi (275.8 kg/da), 14,000 bitki/da bitki yoğunluğundan elde edilmiştir. Kütlü pamuk verimi bakımından genotip x bitki yoğunluğu interaksiyonu değerlendirildiğinde, açık koza dizilişine sahip genotipilerde bitki yoğunluğu 21,000 bitki/da bitki yoğunluğundan fazla olmaması; kloster koza dizilişine sahip pamuk genotipilerinde bitki yoğunluğu 14,000 bitki/da’dan az yoğunlukta olmaması gerektiği saptanmıştır.