سید علی محمد میرمحمدی میبدی

This study was performed to investigate the effects of drought stress on agronomic traits, post-drought recovery, and survival of tall fescue genotypes in the Research Farm of the Isfahan University of Technology located in Lavark, Najafabad, central Iran. In this study, 67 tall fescue genotypes, including three groups of the early, medium, and late in terms of flowering were studied. All genotypes were fully irrigated after planting for two years (2016-2017) and then in the third and fourth years (2018-2019) were examined under three irrigation environments including normal water (50% moisture depletion) mild drought stress (70% moisture depletion), and intense drought stress (90% moisture depletion). Morphological and performance traits were examined. In the summer of the fourth year (2019) after the summer harvest, irrigation was stopped in all drought stress levels for two months. Then the plants were irrigated again for six weeks, and after regrowth, recovery-related traits were evaluated. High genetic diversity was observed among tall fescue genotypes for all measured traits. The results showed that drought stress had adverse effects on forage yield and yield components, recovery traits, and survival. Prolonged drought stress changed the relationships between different traits. Significant positive correlation between the forage yield and recovery rate with drought tolerance indicated that these traits could be used as appropriate selection criteria to increase forage yield and identify superior genotypes in arid and semi-arid regions. The results of this study indicated low to moderate summer dormancy (incomplete summer dormancy) in this germplasm. Negative correlation of functional and stress tolerance traits with day to recovery under drought stress conditions showed that drought tolerant genotypes will have faster recovery than other genotypes. The results showed that some late flowering genotypes (such as 3L, 18L and 11L) are valuable gene sources for forage production. Drought tolerant genotypes with suitable yield in three flowering groups were identified using the biplot and principal component analysis method. These genotypes can be useful for breeding programs in future studies.

Plant genetic variation, during the long-term domestication of the cultivated barley, especially after the modern breeding and intensive cultivation, reduced significantly, leading to genetic erosion in this crop as well. Wild relatives of cultivated barley are potential source of valuable genetic materials for barley improvement. Genetic variation of wild species belonging to primary gene pool of barley is important in employing in barley breeding program, particularly for tolerance to biotic and abiotic stresses. Being a close relative of wild species (H. spontaneum L.) and the lack of tolerance genes among the cultivated genotypes of barley makes gene introgression the appropriate avenue to transfer desired genes such as abiotic stress tolerance.

In this research a backcross populations (BC2F1) developed from interspecific hybridization between cultivated barley and its wild relative (H. spontaneum L.) was assessed for genetic diversity using molecular markers which are valuable to assist background selection for recurrent parent.

Arliquin and POPGENE softwares were used to analyze genetic diversity and molecular variance (AMOVA) among populations, respectively. Gst and Nm parameters had an average of 0.59 and 0.34, respectively, indicating a low gene flow among nine groups of backcross families. The AMOVA results showed that majority of genetic diversity belonged to within population variation (86.48%). Nei's genetic similarity ranged from 0.41 to 0.92 which were consistent with those of genetic distance

Microsatellite markers have strong differentiation ability to discriminate the resultant genotypes from a bi-parental cross.

To evaluate drought tolerance in bread wheat, tritipyrum and triticale genotypes, 27 different genotypes were grown as a randomized complete block design under two irrigation regimes (control and drought) in two locations (Isfahan and Shiraz) during two growing seasons (2016 and 2017). Based on grain yield, several indices including stress tolerance index (STI), tolerance index (TOL), susceptibility index (SSI), mean productivity index (MP), geometric mean productivity index (GMP), drought sensitivity index (SDI), drought index (RDI), stress susceptibility percentage index (SSPI), Harmonic mean index (HARM) and Yield stability index (YSI) were calculated. According to the results of genotypes ranking in Isfahan region, triticale lines had the highest values of MP, GMP and STI indices over two years of study. In Shiraz region, triticale lines (4115 and 4116) had the highest values for drought tolerance indices. According to SSI and TOL indices, (triticale) and wheat genotypes (Bam, Omid and Alvand) were evaluated as drought tolerant genotypes in Isfahan region and Alvand and KaCr4 genotypes in Shiraz region in two years of evaluation. According to the correlation analyses, MP, GMP, HARM and STI indices had a positive and high correlation with grain yield in both stress and non-stress environments in both Isfahan and Shiraz regions. Superior-tolerant genotypes can be used in breeding programs to increase drought tolerance in future.

Knowledge concerning some physiological and biochemical basis of flowering process is essential for achieving higher yield and quality of saffron. This study aimed to elucidate the relation between flower mass ratio and a rough content of carbohydrate, starch and protein of plants do produce flower and non-blooming saffron at flowering stage, affecting on flower development and to determine mass-flowering pattern based on comparison of carbohydrate, and protein content of saffron corms as well as the antioxidant enzyme activities at stages of complete dormancy, flowering and vegetative growth. 120 healthy and uniform weight saffron corms were selected and were grown in a completely randomized design (CRD) with three replicates and placed in a growth chamber. Corms were sampled separately during the dormancy stages (mid-August), flowering (late October) and vegetative growth (January). The results showed that sugar content at flowering stage was increased 65.6% compared to complete dormancy stage and starch content was decreased 32% in vegetative growth stage compared to flowering stage. Catalase enzyme activity was at its maximum level (3 μmol H2O2 min -1 mg-1 protein) and peroxidase at vegetative stage (2.6 μmol POX min -1 mg-1 protein). Due to the lower starch content in plants do produce flower than non-blooming saffron plants, it can be concluded that the plant may convert the starch in the corm of saffron into sugar, depending on its need at the flowering stage, and exchange these two substances as needed. Among the antioxidant enzymes investigated, it was found that the peroxidase enzyme usually acts as a multifunctional enzyme and can enhance or inhibit flower induction.

Droughts are natural events and could lead to declining surface water quality of regional basin. Understanding the complex impacts of drought may help authorities to monitor changes in different regional basin and to make appropriate decision on development of a river basin management plan. In this study 20 years annual precipitation time series from 1994-2013 from 7 synoptic weather stations located in the Halil-Rood basin were analysed using both Standard Precipitation Index (SPI) and Reconnaissance Drought Index (RDI) and then dry (-1.35 to -1.75) and wet years (1/7 to 2.45) were determined by model simulation studies. Several climate based drought indices and remotely sensed based drought indices were used for monitoring and evaluating of drought. The impact of drought on the water quality parameters in the study area was evaluated. Results showed that there was significant relationship between most of the examined water quality parameters (Ca2+, Mg2+, HCO3-, SO42+, Na+, total dissolved solids TDS, SAR) and drought, however there was no significant relationship between water pH and drought. The study indicated that focus on the drought indices might be helpful as a tool in improving surface water resources management under drought condition and may promote sustainable water resources utilization and management in the study area. Also, dividing the Halil-Rood basin into several homogeneous regions is recommended for future studies to prepare a better ground for studying the effect of drought on the quality of water at a regional scale.

The roots of the madder plant (Rubinia tinctorum) contain some pigments that can be used to produce the red dyes. In order to study the effect of salinity on alterations in the amount of plant pigment an experiment was conducted according to a completely randomized design with three replications. Based on the CIE XYZ color space model designed close to human color vision, the results showed that increasing soil salinity decreased the value of The lightness value parameter (L*), but the A* (redness and greenness) and B* (yellowness and blueness) values were increased with increasing soil salinity up to the level of 8 dSm-1. There was a significant positive correlation between A* value and Ca + Mg and a significant negative correlation between L* value and Ca+Mg at the 5% level. Fitting three nonlinear regression model to data, simulated and described the variation of colorimetric specification of woolen samples dyed under different madder dyes and salinity conditions. These models proved to be an appropriate and reasonable link between madder growth conditions and colorimetric specification of woolen samples dyed such as L*, A* and B* values. Due to the high resistant characteristics of madder to salinity, increasing salinity in the madder root zone lead to acceptable quality and efficiency of pigment production and to expand the possibilities for economic production of Rubinia tinctorum in soil salinity in the central arid region of Iran

Plant Breeding has utilized a wide range of techniques and methods to improve the quality and quantity of plants. The molecular markers are the tools that have provided a new perspective for plant breeding advancements. This article has reviewed the various advantages and uses of molecular markers and the utilization of the high potential of natural polymorphisms within communities, combined with the abilities of conventional plant breeding methods. The marker attributes are not subject to environmental influence and their high frequency of these markers in their number, high structural diversity are as part of their benefits in identifying identities, determining the genetic diversity of species and studying relationship between populations. They may aid in discovering more information about protecting and maintaining genetic stock collections, identifying varieties, determining genes with chromosomal location and the number of genes controlling traits. Genome sequencing, the preparation of physical and genetic maps, genomic fingerprinting of plants are some of the other applications of this tool in plant breeding. The high efficiency of selection with the help of markers in selection of genotypes has been emphasized as the parent of crosses and selection with the help of a marker in breeding programs and genomic selection. New technologies offers new opportunities to shape genetic variation in the improvement of specific plant breeding programs. Nowadays development of next-generation sequencing technology, genome sequencing and high throughput approaches for markers have facilitated EST-derived simple sequence repeat (EST-SSR) marker development as well as single nucleotide polymorphism (SNP) marker. These markers can be successfully employed in accelerating research and plant breeding programs.

Microcharacters of seed coat and its surface patterns are valuable in the systematic consideration in some genera. The aim of this study was to introduce the application of these data in assisting the identification of Vicia L. species.Micromorphological traits of 90 seeds from 20 species of the genera of the Vicia were studied in order to answer some systematic questions regarding this genus. The morphology of the surface of these species were examined using a scanning electron microscope (SEM). The results of the observations and analyses indicated that the pattern of seed coat ornamentation was of Papillose type and their SEM pattern varied within and between accessions in terms of tip-shape of the papillae, size (height), and amount of conation of papillae side ride. These traits can be used in taxonomic revision of the Vicia genus. Based on these seed coat ornamentation traits, four categories namely Colliculate with Tuberculate, Aculate projections from projections peaks, Aculate and Tuberculate from below the peak were identified. These analyses can provide good evidence for the close relationship of related species from the different species in a genus. It presents a comprehensive guide regarding variety classification and cultivar introduction.

This study investigated the vegetative and physiological characteristics of Hammada salicornica Syn.: Haloxylon salicornicum under sand burial. Experiment conducted in completely randomised design with five replicates. One year-old seedlings of Hammada salicornica in the same size assigned to one of the following five burial treatments, control, buried to 33% of plant height, buried to 50% of plant height, buried to 75% of plant height and buried to complete plant height. After 6 months watering under glasshouse conditions, some of vegetative and physiological characteristics of Hammada salicornica were measured. Results showed the highest amounts of leave proline equal to 20.8 mg/gfw observed in 33% burial treatment. Root proline in all burial treatments were significantly more than two times compared to control. The root proline in 33% burial traetment was equal to 22.72 mg/gfw that was two times more than control. The amount of oxine significantly increased in 33% and 50% burial treatments compared to control. The amount of oxine in 33% burial treatment was equal to 0.64 mg/gfw that was two times more compared to the control. The amounts of stem sugar were deacreased in all burial treatment while heighest amounts of root sugar were measured in 33% burial treatment. Stem and root sodium, 22 meq/l, significantly increased in 33% and 50% compared to control and 75% burial treatment. The amount of root and stem potassium content in 75% of burial treatment was significantly lower than other burial treatment. The amounts of stem phosphorus, 0.73 meq/L, and root phosphorous, 1.9 meq/L, observed in 33 % of burial treatment. The amounts of root phosphorus significantly increased in all burial treatment compared to the control. Moreover, the stem hieght in 75% burial treatment, 40 cm, were more than two times compared to the control. The highest amount of stem and root dry and wet weight in 33 % of burial treatment was significantly more than other burial treatments. It is concluded that Hammada salicornica tolerate not only 33% of burial treatment but also the burial stimulates the growth.

This study was conducted to evaluate the response of Nitraria schoberi under sand burial. Experiment conducted with two years old sapling with four treatments ( control, 33%, 50%, 66% burial and complete burial). Result showed that the highest concentration of proline (29 mg/gfw) observed in 50% and 66% burial treatment. The lowest concentration of proline (16 mg/gfw) observed in control. The highest concentration of Oxine (0.91 mg/gfw) were measured in 50% burial treatment and the lowest concentration of proline (0.43 mg/gfw) observed in control. The heighest concentration of stem sugar (20 mg/gdw) were measured in complete burial and the heighest concentration of root sugar (40 mg/gdw) were measured in 33% burial treatment. Stem sodium content in all burial treatment was higher than control. There was not significant differences in root potassium between treatments but leaves potassium (0.83 Meq/L) significantly increased in 75% burial treatment compared to control. Increasing burial depth decreased potassium in root and leaves. The heighest concentration of leaves and root phosphorus content were measured in 33% burial treatment equal to 0.75 and 0.68 Meq/L respectively. Adventitious roots obsedved in all burial treatment but no adventitious root observed in control. Stem wet weight were 1.5 times more than ontrol in 33% burial treatment. Root fresh weight significantly increased in 33%, 50% and 75% burial treatments compared to control and complete burial treatments. It is concluded that Nitraria schoberi had vegetative and physiological adaptive responses to different burial treatment.

Genetic variation is essential for the success of breeding programs and is vital to helping the genetic improvement of Triticale. Understanding patterns of genetic diversity in the Triticale and use of its genetic resources on a practical basis may help to establish appropriate procedures for breeding genetic materials. It can be used as a benchmark for classifying parenting lines and favorable heterotic groups in triticale. Triticale (X Triticosecale wittmack) has considerable potential either as a grain crop or forage crop, but has received little attention from breeding programs in Iran.
This research was conducted to study the genetic diversity and the performance of triticale cultivars imported from Poland and International Maize and Wheat Improvement Center (CIMMYT) using some agro-morphological traits. Forty one triticale genotypes were evaluated using a randomized complete block design with three replications at Research Farm of College of Agriculture, Isfahan University of Technology. Agronomic characteristics comprising plant height (cm), length of the last node (cm), flag leaf length (cm), spike length (cm), thousand seed weight (g), the number of spike per m2, seed yield (tha-1), grain number per spike, number of spikelets per spike, harvest index, test weight (kg hectoliter), biological yield (ton ha-1), wet and dry gluten content (%) were measured. All statistical analyses were performed using SAS statistical software. The multivariate analysis procedures used to analyze the collected data and to investigate relationships among variables. Mean comparison was conducted using LSD range test (at 5% level). The unweighted neighbour joining (UNJ) cluster analysis was carried out using NT-SYS software.
Analysis of variance showed that genotypes were significantly different in all characters. The measured traits varied in coefficient of genotypic and phenotypic variation. The highest coefficients of genotypic (41.7%) and phenotypic (44.9%) coefficient of variation were belonged to wet gluten content. The least coefficient of genotypic (4.5%) and phenotypic (7%) variation was denoted to test weight. Simple mean comparisons for seed yield of Triticale showed that the highest seed yield (11.84 ton ha-1) was denoted to Sorento genotype from Poland and the least seed yield (5.5 ton ha-1) to Beaglel and EMA genotypes (from CYMMYT). Using stepwise regression analysis, 98.8% of seed yield variation was attributed to two traits, including harvest index, and biological yield. Correlation analysis showed the significant relation of number of spikelets per spike, and spike length with grain yield. The results of the factor analysis revealed that five factors namely, plant height, grain yield and their components, biological yield, harvest index gluten content explained 80% of total variances of the grain yield. Cluster analysis of genotypes based on agronomic and protein content traits grouped the genotypes into four separate clusters. In categorization based on collected data, the fourth group included genotype from Poland origin (Prego, Lamberto, Moreno, Lasko, Dagro, Sorento, Fidelio, LAD1900, RH116, Tewo, Disco, Vero, DAD601, Pinokio and Magnat) with the highest value for biological yield, seed yield, number of spikelet per spike, plant height, spike length and the length of the last internode. These clusters have beneficial characteristics and are useful for plant breeding purposes.
Based on the data reported here, the scientific use of multivariate statistical analysis including stepwise regression analysis, principle component and cluster analysis of genotypes revealed subjectivity of these methods as a suitable way to exploit intraspecific variation within triticale and evaluate its genetic resources for their agronomic value and the amount of genetic variation for specific traits to allow more efficient genetic improvement. The identified superior genotypes such as Sorento could be used in hybridization programs for improvement the seed yield in triticale.

The adaptability of Haloxylon appilium to adverse environmental conditions and especially its capability for an appropriate establishment in saline and desert soils has introduced this plant as a suitable means for biological methods to stabilize sand dunes, control erosion and prevent desertification in arid regions. In order to evaluate the ecophysiological characteristics of Haloxylon appilium some characteristics of soils under the long term establishment, survival and development of this plant and ion composition of this plant growing in Yazd province in thirty two growing trees of similar ages and traits within 8 locations of Chah Afzal and Ashkezar were investigated and their height (H), crown diameter (CD) and the above ground biomass index (Yi) were measured. Also, after cutting the trees from their collars, soil profiles were dug underneath the tree locations and soil samples were taken at depths of 0-30, 30-60, 60-90 and 90-120cm from four sides of each profile. The samples were then analyzed for Electrical Conductivity (EC), pH and Cl, Na, Ca, Mg, K concentrations in 1:5 soil to water extracts. The results showed statistically significant differences in soil parameters between the two regions, except for pH and Mg concentrations. The ion concentration of the plants in the two regions showed statistically significant differences for only Cl in shoots and Ca in roots. Based on the plant growth indices the Chah Afzal and Eshkezar regions were respectively evaluated as suitable and unsuitable for Haloxylon appilium growth. In spite of a higher salinity, the higher Ca and K concentration and lower Na/K ratio of Chah Afzal soils may explain the better plant performance in this region against Eshkezar, however, comprehensive researches on application of Ca and K fertilizer are needed to confirm this hypothesis

The ability of hydrogels to absorb large amounts of water implies that they both provide less soil water losses by preventing deep percolation of water and also increase water use efficiency of plants leading to decrease the effects of water deficiency due to salinity stress on crops. To study the effect of two types of superabsorbent (Stockosorb and Xanous) on growth of greenhouse cucumber under saline-soil conditions, a factorial experiment based on completely randomized design with 12 replications was carried out in Research Greenhouse of Yazd University. At the first stage of the experiment, effect of applying superabsorbent polymers (Stockosorb and Xanous) at three levels (0, 3 and 6 g/kg dry soil) was investigated 25 days after planting by measuring different characteristics including number of leaves, plant height, leaf length and leaf width. At the second stage, the abovementioned characteristics, along with the number of flowers and fresh and dry weight of plants, were measured 35 days after planting. Results indicated that at both stages, adding Stockosorb to the saline soil (EC= 5 dS/m) significantly increased all measured parameters when compared to the control. Application of two levels of Xanous hydrogel to the saline soil had no significant effect on measured traits, except on number of flowers, as compared to the control. Variations of number of flowers in both hydrogel treatments, and at both application levels, showed that using superabsorbent could be important in enhancing the crop yield under difficult saline conditions.

The herbicidal properties of some plants species can be exploited successfully as a tool to reduce the herbicide application. Wild plant species, including medicinal herbs, usually contain much higher levels of chemicals compounds than the cultivated crops; therefore it can be used to control the weed species. The current study was conducted inorder to evaluate the herbicidal properties of Capparis spinosa on Malva parviflora in both laboratory and greenhouse conditions. A factorial experiment was used with three replications. Evaluated factors including used parts of plant (foliage, root) as well as plant material amount (four concentrations of aqueous extract; 0, 0.6, 0.9, 1.25 g dry weight per 100 milliliter water; in laboratory condition and four amount of plant powder; 0¡ 4¡ 8¡ 12 g dry weight per 1000 g soil; in greenhouse condition). The results indicated that, in laboratory condition, with increasing concentration of Capparis spinosa aqueous extract from 0 to 12%, mean time to germination of M. paryiflora increased progressively from 1 to 1.4 and 2.2 days, respectively. At 1.25% aqueous extract concentration, the germination percentage, root and soot length as well as root and shoot dry weight diminished 87, 90, 91, 83 and 73%, respectively, when compared to the control. Also in greenhouse condition, the effects of Capparis spinosa powder added to the soil on measured parameter were significant. In the soil treated with 12g powder, seedling length of Malva parviflora in the second week of growth reduced about 47% when compared to the control. Overall, the results revealed the possibility use of herbicidal properties of Capparis spinosa for biological weed control and therefore reduce application of chemical herbicides.

The purpose of this study was to describe the correlations between wheat grain yield (GY) and its components, under environmental stress and non-stress conditions, and recognition of the most effective yield components and their development stages in making interaction with the environment. Two generations of F3 and F4, produced from a cross between Oste-Gata (drought tolerant) and Massara-1 (susceptible) genotypes, were used for evaluation in two years (2005 and 2006) at Research Farm of Isfahan University of Technology, Isfahan, Iran. Analysis of correlation of yield and yield components showed that grain yield was significantly correlated with grain weight per spike, number of grains per spike and number of spikes per m2. Results of Tai analysis revealed that under stress, grain weight per spike and under non-stress condition, number of spikes per m2 had the highest direct effect on GY in both generations. Assay of genotypic components showed that under stress conditions, grain weight per spike and number of grains per spike, and under non-stress conditions, number of spikes per m2 had the highest effect on genotype × environment interaction and their developmental stages (grain filling, reproductive and pollination). In non-stress condition, spike number per m2 had the same effect. Analysis of environmental components indicated that the most environmental sensitive period of plant growth was grain filling stage. Large difference between early and late growth stages is related to high sensitivity of grain filling period and reproductive stage to environmental conditions and the occurrence of drought stress at reproductive stage. Therefore, trend of grain yield variations under stress conditions was affected by grain weight per spike and showed the highest amount of environmental interaction at its growth stage.

Seed germination as the most important plant development stages can be frequently affected by environmental stress including drought and salinity. The seeds and/or fruits of many species in desert habitats have an external mucilage layer that can be increased water holding capacity of seeds under water stress condition. To evaluate the role of mucilage in enhancing of drought tolerance of Plantago ovata Forsk. and Plantago major L. in seed germination and early growth stages، a completely randomized experiment was conducted in a factorial arrangement with four replications. Plant species (P. ovata، P. major)، drought stress levels (0، -5، -9، - 14. 5، -21 MPa) and seed type (with mucilage، and without mucilage) were considered as first، second and third factors، respectively. Different variables including germination percentage، rate of germination، stem as well as root length were measured. Results indicate that with increasing drought stress، germination and seedling growth of two plant species were significantly decreased. Seeds with mucilage were less affected by drought stress compared to the seeds without mucilage. Germination and early growth of the two plant species differ in their sensitivity to drought stress and P. major was more affected by drought stress. Overall، results indicate that mucilage can improveseed germination of both plant species under drought stress condition. However، the ability of mucilage in improving seed germination depends on type of plant species and amount of seeds mucilage.

Identification and determination of genetic purity of rice hybrid varieties for seed certification and control is an essential issue regarding to apply hybrid rice technology in Iran. Therefore، usefulness of microsatellite markers (SSR) for fingerprinting and genetic purity testing were investigated. Eight F1 rice hybrids and their parental lines were evaluated using 14 microsatellite markers in which 10 markers had reproducible polymorphic bands among genotypes. Totally 27 bands (alleles) produced، average number of band per primers and per genotypes were 1. 92 and 1. 68، respectively. Genetic purity was tested in respect of microsatellite fingerprint and polymorphic primers which detected off types seeds among F1 hybrids. Extra band (s) was also observed when the F1’s SSR products were analyzed. Null alleles were appeared in three restorer lines for RM264 microsatellite locus. Cluster analysis based on shared allelic similarity coefficient، using UPGMA algorithm، grouped the 16 rice genotypes into three main clusters، each containing 43. 75%، 43. 75% and 12. 5% of genotypes. Overall، these results indicated there are reliable tools of microsatellite markers in DNA profiling and seed purity testing in rice varieties، especially hybrids.

In this experiment, markers linked to the gene(s) controlling days to heading, days to anthesis and days to maturity were identified in a segregating population of 151 F3 and F4 families derived from the cross between Oste-Gata as drought tolerance and Massara-1 as susceptible durum wheat genotypes. The traits were assessed in field trails in two environmental conditions in 2003 and 2004 cropping cycles. From 200 markers screened in this study, 30 markers which were polymorphic distributed on different wheat chromosomes, except 2A, 4A and 6B.. Based on single marker analysis, Xgwm148-2B and Xwmc45-7A showed association with days to heading under two environmental conditions and explained 19% of the total phenotypic variation. For days to maturity, Xcfa2114-6A closely associated with other traits under stress and non-stress conditions. The presence of markers that were exactly located at the same regions of chromosomes reflected high correlation between traits. Composite interval mapping identified 3, 2 and 2 QTLs for days to heading, days to anthesis and days to maturity, respectively. These QTLs were located on chromosome 2B and 3B for days to heading and days to antheisis and 3B and 5A for days to maturity, respectively. These QTLs could explain about 10% of phenotypic variation of phenological traits.

In order to have a successful breeding program, it is important to determine the relationship among the traits. This study was conducted at Research Farm of Isfahan University of Technology to evaluate relationships among some of the agronomic and physiological traits and grain yield of ten bread wheat cultivars in optimum and stress moisture (irrigation after 70±3 and 130±3 mm evaporation from class A pan) conditions in year 2006. Grain yields in both moisture conditions had significant positive phenotypic and genetic correlations with harvest index, number of grain/spike, RWC, chlorophyll a and sum of chlorophylls a and b and had significant negative correlation with RWL. Significant positive correlation were observed between peduncle weight at heading stage and difference of peduncle weights at stages heading and maturity with grain yield and RWC in moisture stresss condition. Factor analysis detected 6 and 7 factors which explained 94% and 94/6% of the total variation in moisture stress and non stress conditions, respectively. Results of canonical correlation analysis in non stress condition showed that among the agronomic traits, days to heading and 1000-grain weight and among the physiological traits, SLW and RWC had the highest contributions to the first pair of canonical variables. Results of canonical correlation analysis in stress condition showed that among the agronomic traits plant height and heading date and among the physiological characters RWC and SLW had the highest contribution to the second pairs of canonical variables.

A hydroponic experiment was conducted to evaluate the effects of salt stress on safflower genotypes under greenhouse conditions. The experiment was arranged as a factorial one based upon a completely randomized design with three replications. Five safflower genotypes (Arak2811, Nebraska10, SOD25, CA116, and CA128), and four salinity treatments (0, 0.3, 0.5, and 0.7 percent of NaCl) were employed as experimental factors. Salinity exerted considerable effect on the growth parameters. Plant height, shoot and root dry weight, the concentrations of Na, K, Ca, and Mg in leaves and roots, and also the concentration of proline in leaves were meseared in samples obtained from the plants harvested one month after being exposed to salinity. Salinity decreased plant height, shoot and root dry weight, as well as the concentration of K, Ca, and Mg in leaves and roots. Howevere, the concentration of Na in shoots and roots increased under saline conditions. There was a significant interaction between the levels of salinity and genotypes for shoot dry weight. Among tested genotypes CA128 showed to be more salt tolerant in terms of dry matter accumulation regarding all levels of salinity. The effect of salinity on shoot/ root ratio was not significant. The concentration of proline in the leaves increased in saline treatments but the differences between genotypes and the interactions between the levels of salinity and genotypes were not significant as far as the concentration of proline in the leaves is concerned. The ratio of Na/K in the leaves and roots was higher in the plants subjected to salt stress. The differences between genotypes were significant regarding this ratio. Among the tested genotypes the ratio of Na/ K in the leaves was highest for Nebraska10. Howevere, the interaction between the levels of salinity and genotypes was significant for the ratio of Na/ K in plant tissues. The results of this experiment showed that salinity can significantly affect the growth of safflower and the responses of safflower genotypes to salinity might be different in terms of dry matter accumulation and in terms of ionic relations.

A complete randomized block design with 42 barley lines was conducted at research farm at Isfahan University of Technology to evaluate their agronomic traits in two and six-row barley genotypes with triplicates. Differente agronomic traits and grain protein content were determined at different plant growth stages. The results indicated that the weight of grain per ear and the number of grain per ear had the highest coefficient of variation while the number of ear per area unit had the lowest. There was high genetic variation among the studied lines for all traits except grain protein. The number of row per spike demonstrated significant effect on number and weight of grain per ear، plant height، biological yield، grain yield، growth rate and the harvest index. The two-row barley lines revealed higher plant height، biological yield and growth rate while had lower grain yield، number and weight of grain per ear and harvest index in comparison to six-row genotypes. The number of row per spikle did not show significant effect on day to heading، number of ear per area unit and grain protein. Stepwise regression result showed that harvest index and biological yield accounted for 98. 6% and 98. 7% percentage of variation for grain yield in two and six row barley، respectively.

This study was conducted in Research Farm of Isfahan University of Technology to evaluate some of the agronomic and physiological traits and grain yield potentials of ten bread wheat cultivars using a split plot design with three replications. Main and sub plot consisted of optimum and stress moisture treatments (irrigation after 70±3 and 130±3 mm evaporation from class A pan) and wheat cultivars, respectively. The results of analysis of variance revealed significant effect of moisture treatments on all traits except 1000-grain weight, harvest index, specific leaf weight, assimilate redistribution and difference of peduncle weights at heading. Significant differences were found among genotypes in the stress condition except for chlorophyll b and chlorophyll a to b ratio. Significant differences were detected among genotypes in optimum moisture condition for all characters, except for chlorophyll b, chlorophyll a to b ratio, harvest index and assimilate redistribution. Grain yields in two moisture conditions had significant positive phenotypic and genetic correlations with harvest index, number of grain/spike, RWC, chlorophyll a and sum of chlorophylls a and b and had significant negative correlation with RWL. Significant positive correlation was observed between peduncle weight at heading stage and difference of peduncle weights at stages heading and maturity with grain yield and RWC in moisture stress condition. The results of path analysis for phenotypic correlation coefficients between grain yield and their corresponding traits in the regression model showed that in stress condition harvest index had the highest direct and positive effect on grain yield and in non stress condition chlorophyll a had the highest direct and positive effect on grain yield. Results of stepwise regression analysis in non stress condition revealed that chlorophyll a, plant height and harvest index explained more than 90% of grain yield variability. Based on stepwise regression analysis in non stress condition, RWL, harvest index and RWC explained 95% of grain yield variability.

Field crop landraces are valuable genetic sources. Twenty populations of Persian clover (Trifolium resupinatum L.) collected from different areas of Iran were used in this study. DNA extractions were carried out using minipreparation method with equal amount of leaves from 30 plants of each population. DNA samples from 20 clover populations were evaluated using semi-random (ISJ) markers. Ten primers out of 30 which used IT (intron-targeting) and ET (exon-targeting) primers produced repeatable bands. Cluster analysis was conducted using NTSYS software and UPGMA method based on Jaccard's similarity matrix. Primers totally produced 111 bands, of which 93 bands (%93) were polymorphic among clover genotypes. The greatest and least amplification fragments belonged to IT15-31 and ET18-4 primers, respectively. Average band number per primer was estimated 11.1 bands. Furthermore, IT primers produced more polymorphic DNA fragments with higher resolution. Based on cluster analysis and cutting dendrogram in 0.8 similarity coefficients, clover populations were divided into five groups in which Kazerun and Kermanshahi (1) individually formed a separate cluster. According to similarity matrix, the least similarity (%42) belonged to Alvijan and Kazerun and the highest similarity belonged to Chegeni and Haftchin Hamedan. Clustering based on semi-specific PCR method almost substantiated the grouping based on geographical origin. Considering the results, it is concluded that PCR-based semi-random marker technique can be used for genetic diversity study of Persian clover as well as discrimination of its cultivars.

The influence of late-season drought stress on grain yield, its components and some other morpho-physiological traits was evaluated using 151 F3 families obtained from crossing a drought tolerant genotype with a drought susceptible genotype at Research Farm of Isfahan University of Technology in 2003-2004. Two separate randomized complete block designs each of which having two replications allocated to each of moisture stress and irrigated (non-stress) environments. Drought stress significantly affected grain yield, its components, harvest index and relative water content (RWC) traits. Analysis of variance of combined data revealed significant differences among the environments for the traits that related to reproductive stage. The genetic and phenotypic correlation coefficients between grain yield and most of traits such as RWC and excised leaf water retention (ELWR) were significant. Based on stepwise regression analysis, biological yield and harvest index were the most efficient traits in explaining the grain yield variation under normal and stress environments, respectively, Factor analysis of data from the two environments indicated that components were related to phenologic characters, potentional of plant production, harvest index and yield components, plant height and physiological traits. The amount of variation explained by these components varied for two environmental conditions where yield components, plant height and physiological traits had a high impact under stress environment. Cluster analysis of families based on all of traits for two environments defined desirable clusters. This cluster divided families into five groups each of which desirable for a particular trait such as high or low grain yield in stress environments, early maturity, late maturity, high RWC and high ELWR.

Drought stress is one of the most important environmental stresses that reduces grain yield dramatically. Grain yield results as a complex trait from contribution of many traits in plant, and evaluation of morphological traits with less complicated inheritance under different environmental conditions and related to grain yield could be used as selection criteria. To study the genetics of traits related to plant stature and flag leaf area, a cross was made between durum wheat cultivars Oste-Gata (drought tolerant) and Massara-1(susceptible). Their F1, F2 and F3 progenies were evaluated under normal and late-season drought stress using a randomized complete block design. Generation mean analysis was performed by scaling test which essays all generations simultaneously. Analysis of variance of generations showed that all traits except of width of flag leaf, differed significantly between generations. Three parametric models contain m, d and h had the best fit. Although both additive and dominance components were involved in the expression of all the traits under both environments, yet the dominance component suffered more than the additive component. Dominance variance was contributed in plant height, peduncle length and length of flag leaf more than additive variance. Therefore, these traits can not be used as selection criteria. There was no epistatic effect for the studied traits, indicating the lack of gene intractions for the traits in the segregating populations.