Tolerance to freezing stress in Cicer accessions under controlled and field conditions

Freezing tolerance was determined in 5 annual wild Cicer and 225 Cicer arietinum L. accessions, grown both in field and controlled conditions. In controlled conditions, the temperature was decreased 5°C daily to achieve -20°C. Field trial was conducted at Urmia, Iran. In general, 'kabuli' chickpeas were more susceptible to freezing stress than 'desi' chickpeas. Some 'kabuli' types such as FLIP 93-261C and x03TH21 which presented high freezing tolerance during early seedling stage, withstood -15.6°Cwithout snow cover. Based on severity score data, the highest freezing tolerance sources were all accessions of Cicer echinospermum and Cicer reticulatum and 15 lines from C. arietinum germplasm. The results obtained in controlled conditions were approximately confirmed in the field conditions. The most resistant genotypes to freezing stress were wild accessions of ILWC 81, ILWC 106, ILWC 139, ILWC 181, ILWC 235, and cultivated lines, Sel 96 TH 11404, Sel 96 TH 11439, Sel 96 TH 11488, Sel 98 TH 11518, x03TH21 and FLIP 93-261C. Our results indicated the possibility of autumn sowing of chickpea in the high plateaus of Iran

Correlation and path-cofficient analysis of seed yield and yield related trait in Iranian confectionery sunflower populations

This study was undertaken in order to determine the association among yield components and their direct and indirect effects on the seed yield of confectionery sunflower. 36 confectionery sunflower populations originated from different regions of Northwest Iran were characterized using 11 agromorphological traits including: Days to 50% flowering, plant height, stem diameter, head diameter, number of leaves, leaf length, leaf width, petiole length, number of seeds per head, 100-seed weight and seed yield. Phenotypic correlations results show that seed yield per plant was positively and significantly associated with 100-seed weight, head diameter, number of seeds per head, stem diameter and plant height. Path coefficient analysis revealed that number of seed per head, 100-seed weight, and head diameter has positive direct effect on seed yield. Therefore, selection based on these characters would be more effective to improving seed yield in confectionery sunflower in breeding programs.Key words: Helianthus annuus L., direct effect, phenotypic correlation, indirect selection

Collection, evaluation and classification of Iranian confectionary sunflower (Helianthus annuus L.) populations using multivaraite statistical techniques

Characterization of confectionary sunflower germplasm resources is critical to their efficient collection and management as well as for breeding programs. Thirty six (36) confectionary sunflower populations originating from different regions of Northwest Iran were characterized using 15 agro-morphological traits. Among the studied traits, high coefficients of variation were observed for harvest index (48.36), seed yield (42.07) and petiole length (41.63). Cluster analysis using Ward's method classified the 36 populations into four groups. A large number of genotypes was placed in cluster III (16 genotypes) followed by cluster I (13), cluster IV (4) and cluster II (3). Clusters I, III and VI include genotypes from different sources indicating no association between clustering pattern and eco-geographical distribution of genotypes. The maximum inter-cluster distance of 9.03 was observed between clusters II and VI indicating the possibility of high heterosis if individuals from these two clusters are cross-bred. Principal component analysis resulted in the first four components with Eigen value greater than one accounting for 78% of the total variation. The results of PCA were closely in line with those of cluster analysis. These results can now be used by breeders to develop high yielding sunflower hybrids.Key words: Cluster analysis, confectionary sunflower, genetic variability, principal component analysis

Combined efficacy of silver nanoparticles and commercial antibiotics on different phylogenetic groups of Escherichia coli

NO ABSTRACT AVAILABLESilver nanoparticles (Ag-NPs) can attach to flexible polymeric chains of antibiotics, hence it can be used in combination with antibiotics against resistant bacteria. In this study, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and MBC/MIC ratio of Ag-NPs and antibiotics (gentamicin, tetracycline, erythromycin, ciprofloxacin, nalidixic acid, cefixime, cephalexin, amoxicillin, ampicillin, and penicillin) were quantified against 50 Escherichia coli isolates (25 human urinary tract infection and 25 avian colibacillosis). All isolates had been assigned as four phylogenetic groups A, B1, B2, and D. The results showed that the majority of the human and broiler isolates belonged to phylogenetic groups A and B2. MBC/MIC ratio of Ag-NPs in combination with antibiotics was assessed. It was found that the MIC of the majority of broiler isolates to Ag-NPs was equal to or greater than 50 μg/ml. To conclude, a combination of penicillin and ciprofloxacin with Ag-NPs exhibited profound impact against isolates, the combinations might be applicable for treating multidrug-resistant bacteria

Allelic polymorphism of 'Makoei' sheep myostatin gene identified by polymerase chain reaction and single strand conformation polymorphism

Myostatin, a transforming growth factor-beta (TGF-) super family member, has been well documented as a negative regulator of muscle growth and development. Myostatin with 376 amino acids is synthesized as a precursor protein. In this study, polymorphism of myostatin gene in Iranian 'Makoei' sheep breeds was investigated by polymerase chain reaction and single strand conformation polymorphism technique (PCR–SSCP). Genomic DNA was isolated from the blood of 92 sheep. A 417 bp myostatin intron 1 segment was amplified by standard PCR, using the locus specific primers. Four different SSCP patterns, representing four different genotypes, were identified. The frequencies of the observed genotypes were , 0.293, 0.130, and 0.163 for AD, AC, AE, and BC, respectively. Allele frequencies were 0.4185, 0.0815, 0.2283, 0.2065 and 0.0652 for A, B, C, D and E. Observed heterozygosity (Hobs) value was 0.7192. The chi-square test showed significant (P<0.05) deviation from Hardy-Weinberg equilibrium for this locus in studied population.Key words: Myostatin gene, polymerase chain reaction (PCR), single strand conformation polymorphism technique (SSCP), Ovis aries

Towards mapping ecosystem resilience from space:canopy defensive properties in European temperate forest revealed with spaceborne imaging spectroscopy

Foliar functional traits are dynamic plant properties that vary across space and time, serving as principal tools for monitoring plant physiology and terrestrial ecosystem processes. Phenolics are the most crucial secondary metabolites that play key roles in plant defence against biotic and abiotic stressors, leaf decomposition, as well as consequent influence on nutrient cycling and soil microbial composition. However, spatially continuous information on canopy phenolic remains poorly characterized at the landscape level. Current and proposed spaceborne imaging spectrometers offer unique opportunities to map foliar phenolics quantitatively through space and time. Our recent work (Xie et al, 2024) demonstrated that foliar phenolics can be accurately estimated across temperate tree species using leaf spectroscopy. In this study, we leveraged imaging spectroscopy data from PRecursore IperSpettrale della Missione Applicativa (PRISMA) mission to predict and map foliar phenolic variations at canopy scale in a mixed European temperate forest. Two data-driven approaches, namely partial least square regression and Gaussian processes regression, were applied to link lab-measured phenolic concentration with PRISMA plot-level spectra (400–2400 nm). The performance statistics indicated reasonable precision and accuracy of the model results. Maps derived from the best-performing model (based on cross-validated nRMSE) provided a wall-to-wall assessment of canopy phenolics, capturing both inter and intra-species variations across the landscape. Further, we compared the phenol map with the distribution of leaf mass per area and canopy nitrogen. The results indicated that the synergy patterns across the three functional traits were consistent with the known leaf economic spectrum. These findings highlight the potential of spaceborne imaging spectroscopy to characterize spatial and temporal dynamics of ecologically important plant phenolics. Our study also paves the way for improved global monitoring of ecosystem integrity and plant responses to environmental stress and climate change, particularly with the anticipated launch of hyperspectral missions like ESA’s CHIME and NASA’s SBG

Meta-analysis of the detection of plant pigment concentrations using hyperspectral remotely sensed data

Passive optical hyperspectral remote sensing of plant pigments offers potential for understanding plant ecophysiological processes across a range of spatial scales. Following a number of decades of research in this field, this paper undertakes a systematic meta-analysis of 85 articles to determine whether passive optical hyperspectral remote sensing techniques are sufficiently well developed to quantify individual plant pigments, which operational solutions are available for wider plant science and the areas which now require greater focus. The findings indicate that predictive relationships are strong for all pigments at the leaf scale but these decrease and become more variable across pigment types at the canopy and landscape scales. At leaf scale it is clear that specific sets of optimal wavelengths can be recommended for operational methodologies: total chlorophyll and chlorophyll a quantification is based on reflectance in the green (550–560nm) and red edge (680–750nm) regions; chlorophyll b on the red, (630–660nm), red edge (670–710nm) and the near-infrared (800–810nm); carotenoids on the 500–580nm region; and anthocyanins on the green (550–560nm), red edge (700–710nm) and near-infrared (780–790nm). For total chlorophyll the optimal wavelengths are valid across canopy and landscape scales and there is some evidence that the same applies for chlorophyll a