Hassan Pakniyat

This experiment was performed to evaluate the correlation between grain yield and other characteristics of 20 cultivars and advanced breeding lines of barley in the Research Station, Agricultural collage, Shiraz University, Shiraz, Iran. The experimental design was a randomized complete block with four replications. Biological and grain yields and yield component were measured. Genotypic and phenotypic variation, mean comparison, correlation coefficient, regression and Path analysis were used for analysis of data. The Path analysis showed that the effects of spikes per square meter, kernel weight on grain yield were significantly different (p . Also the results showed spikes per square meter had a negative correlation with kernels per spike and kernel weight. Regression analysis confirmed that kernel per spike is the most important yield component and increasing it can be improved the grain yield.

Water shortage and drought stress in the reproductive stage of wheat (Triticum aestivum L.) considerably affect grain yield (GY). Mapping genes for drought tolerance assists in selection for drought improvement. In the present study, we evaluated breeding values based on best linear unbiased predictions (BLUPs) and drought tolerance/susceptibility indices (DT/SIs), and identified marker–phenotype associations in 220 doubled haploid (DH) lines. The DH lines were evaluated for GY and 1000-grain weight (TGW) under drought stress and well-watered conditions at the heading stage in 2015 and 2016. The linkage map comprised 1333 SSR, DArT and SNP markers with an average density of 2.18 markers per cM. The BLUPs were significantly correlated with GY of the lines. Significant correlations were found between stress tolerance score (STS) and drought response index, yield index, yield stability index, geometric mean productivity and stress tolerance index. The lines DH_R295 and DH_R360 had the ...

Co-expression analysis is a useful tool to analysis data and detection of genes that act in the same pathway or biological process. Echinacea purpurea is one of the most important medicinal plant of the Asteraceae family that is known as antioxidative and antiviral agent. Despite medicinal importance of E. purpurea, very few reports are available for metabolic mechanisms in this plant. With the aim to elucidate the gene expression profiling and identification of modules in E. purpurea, we performed a systems biology analysis on publicly available transcriptome data. Gene ontology and KEGG pathway enrichment analysis revealed that the unigenes were highly related to the cellular process, primary metabolic process, carbon metabolism and biosynthesis of antibiotics. The coexpression networks divided genes into multiple modules. Of these, module M2 associated with secondary metabolic process. Moreover, a total of 47 transcription factor families such as bHLH, bZIP, C2H2, MYB and WRKY in...

The PM H+-ATPase gene family consists of 12 members in Arabidopsis thaliana denoted to Auto-inhibited H+-ATPase 1-12 (AHA1-AHA12). This gene family performs crucial roles in many aspects of plant growth and development such as ion and metabolite transportation, pollen development, stomatal opening, signalling process, and adaptation to abiotic stresses especially thermal changes. The H+-ATPase action dynamically fluctuates during thermal changes in order to enhance adaptation strategies in plants. Based on the fact that surface temperature on average is typically warmer in lower latitudes and cooler in higher latitudes, the association of PM H+-ATPase genetic variants (SNPs) with latitude intervals was studied using chi-square testing of 1001 Genomes project data. The results indicated a significant association between nucleotide substitution and latitude interval, and therefore a geospatial paradigm of PM H+-ATPase nucleotide substitution was established. A>T and T>A substitu...

Drought is one of the most important abiotic stresses affecting wheat growth. Evaluation of a structured population over seasons and moisture conditions allow for the detection of genes involved in drought tolerance. The aims of the present study were to analyze root and agronomic characters under two moisture conditions and identify marker-trait associations in 220 doubled haploid (DH) lines developed from a cross between Kukri and RAC875. The DH lines were evaluated for grain yield (GY) and several root and agronomic traits in four trials included drought stress experiments (DrExp) at heading stage and well-watered conditions (NExp) throughout the growth season in 2015 and 2016. A linkage map comprised of 1333 SSR, DArT and SNP markers were used for the analysis of quantitative traits loci (QTL). The results of QTL analysis showed that four and seven QTL were identified for root traits in the DrExp 15 and DrExp 16 trials, respectively. The results of QTL analysis suggested that the contribution of the three genomes to drought tolerance was not similar. The Q.Rdrw-4A QTL explained 7.05 and 10.43% of root dry weight variances in the DrExp15 and DrExp 16 trials, respectively. A QTL mapped on the D_GA8KES401CIKOJ–160-BS00067285_51 marker interval for root length was co-localized with a QTL for grain weight per spike under drought conditions. A year-specific main effect QTL and several stable epistatic QTL were identified for days to heading in the DrExp and NExp experiments, respectively. Search for gene annotation in the wheat genome showed that the position of this QTL was overlapped with the tRNA, sRNA and protein-encoding genes. Three QTL were identified for GY of which the Q.Gy-2D QTL identified in NExp 16 whilst Q.Gy-3D and an epistatic effect detected in drought conditions. The common QTL identified allows for increasing selection efficiency and the fine-tuning of root and agronomic traits for sustainable wheat production under water deficit conditions.

Cytological analyses were performed in nineteen accessions belonging to seven Achillea species. The results indicate that two species, A. filipendulina and A. tenuifolia, are diploid (2n = 2x = 18) and three species, A. bieberstinii, A. pachycephala, and A. aucheri are tetraploid (2n = 4x = 36). For two latter species, the chromosome numbers are new. Two ploidy levels of 2n = 6x = 54 and 2n = 8x = 72 in A. millefolium and two ploidy levels of 2n = 2x = 18 and 2n = 4x = 36 in A. santolina species were found. Cluster analysis based on chromosomal characteristics and karyotype asymmetry indices clustered the studied genotypes into three major groups. The first group included the diploid species (A. filipendulina, A. santolina and A. tenufolia), while the second group comprised tetraploid species (A. santolina, A. aucheri and A. pachycephala). A. millefolium (hexaploid, octaploid) and A. bieberstinii (tetraploid) were classified in the third group. Total form percentage (TF%) in groups ...

Eight genotypes of spring safflower (Carthamus tinctorius L.) were evaluated for several physiological traits under stress and non-stress water regimes. Data were analyzed using principal factor analysis. The factor analysis technique extracted six factors under nonstress conditions. Six factors explained about 80% of the total variation, and only 40% of the variance was accounted for by the first two factors. Factors I and II were identified as water consumption, and water balance capacity, respectively. Similarly, seven factors were extracted under stress conditions, and 34% of the total variation was accounted for by the first two factors. Factors I and II were described as water conservation, and water holding capacity, respectively. Important physiological criteria were recognized by Factors I and II in two experiments. Ultimately, initial water content (at stem elongation and grain filling stages), canopy temperature (at stem elongation and flowering stages), and leaf water po...

ABSTRACT To investigate genetic variation, and identification of tolerant genotypes according to quantitative indices of drought tolerance, 8 sesame genotypes were tested in a randomized complete block design with three replications under optimum and limited irrigation at the Research Station of College of Agriculture, Shiraz University. Based on the potential yield and yield under stress, quantitative indices of drought tolerance such as mean productivity (MP), geometric mean productivity (GMP), harmonic mean (HM), stress tolerance index (STI), stress susceptibility index (SSI) and tolerance index (TOL) were determined. The result of analysis of variance exhibited highly significant differences among the genotypes for all the indices measured, and yield under optimum and limited irrigation, indicating the existence of genetic variation among genotypes, and thus the possibility of selecting drought tolerant genotypes. Mean comparison displayed that the highest potential yield, stress yield, MP, GMP, HM and STI were related to the genotype number 5. Correlation analysis between indices, mean potential and stress yields indicated that every four indices are suitable for screening the genotypes. Based on these indices and higher yields under optimum and limited irrigation the best drought tolerant genotypes were identified to be genotypes number 4 and 5. Multivariate biplot indicated that the genotypes number 4 and 5 were located next to the vectors of drought tolerance indices, including MP, GMP, HM and STI. Cluster analysis showed genetic distance among genotypes. As a result, genotypes number 4 and 5 were identified as drought tolerant and genotypes number 1, 2 and 3 as susceptible to drought.

Fifteen Iranian wheat cultivars (Triticum aestivum L.) were compared for salt (NaCl & Na 2 SO 4 in 1:1 ratio) tolerance using three treatments: 1.26 (control), 6.8 and 13.8 dSm -1 in a green house. During vegetable growth, shoot Na + , K + , K + : Na + ratio and agronomic traits such as 1000-grain weight, grain yield, biological yield, number of tillers, number of fertile tillers, spike length, salinity susceptibility index (SSI) and salt tolerance index (STI) were measured. In general, tolerant cultivars (Kavir, Niknejad, Chamran & Falat) with better agronomic performance, contained low Na + and higher K + and K + : Na + ratio compared to non-tolerant ones (Ghods, Bayat, Cross Adl & Zarin). Shoot Na + content was negatively correlated with grain yield (r = -0.37, p< 0.05). There was a negative correlation between shoot Na + content and STI (r = -0.66, p< 0.01) and a positive one with SSI (r = 0.71, p< 0.01). These two indexes may be useful for selection of tolerant cultiva...

In this study, the effects of salinity stress (NaCl) on the activity of Catalase (CAT), Guaiacol Peroxidase (POD), and Superoxide dismutase (SOD) were studied in leaves of fifteen oilseed rape (Brassica napus L.) cultivars (Champlain, Hayola401,Licord, Modena, NK Aviator, NK Karibik, NK Octan, Okapy, Opera, PF, RGS, RNX 3621, SLM046, Talayeh, Zarfam). Plants were grown in a greenhouse under control (ECe= 0.9 dSm-1), and two levels of salinity stress (ECe = 6.9 and 11.9 dS m-1) respectively. A factorial experiment was performed in a completely randomized design (CRD) with 3 replications. Salinity stress had significant effect on activity of these enzymes, obviously decreased CAT activity and increased POD and SOD activity in some oilseed rape cultivars under both salinity levels. Zarfam and Licord with the highest level of enzyme activity under both control and salinity stress are reported as the most tolerant cultivar, while NK Aviator having the lowest enzyme activity, is mentioned...