Genetic Diversity in Spring Wheat Landraces from Northwest of Iran Assessed by ISSR Markers

Inter Simple Sequence Repeat (ISSR) markers were used to study the genetic diversity of 18 spring growth type landraces from Iran and selected 9 cultivars grown in Iran out of 15 ISSR primers .11 primers were found to have enough polymorphism and they were used for assessment. These primers are composed of di, tetra and penta-nucleotide sequences. From a total of 108 DNA fragments produced, 78 (72.22%) fragments were polymorphic. The UPGMA clustering algorithm classified the varieties into three major groups .Majority of landraces located in each group were originated from common locations. The results revealed that ISSR markers could be efficiently used to evaluate genetic variation in the wheat germplasm. Genetic similarity and dissimilarities among genotypes will be useful for genetic differentiation of wheat accessions, selection strategies and genetic development of crop plants

Evaluating Freezing Resistance in Barley (Hordeum vulgare L.) Using Molecular Markers and Some Physiological Traits

To evaluate the freezing resistance and genetic diversity in barley physiological traits, molecular markers and their relationship in 20 barley genotypes were assessed in field and greenhouse condition. The analysis of variance showed a significant difference among studied genotypes. The effect of acclimation temperature on prolin content, quantum efficiency of photosystem II, chlorophyll and soluble sugars content were studied as physiological traits. Freezing treatments were -4, -7, -10, -13 and -16°C temperatures that applied in a 3 replicated randomized complete block design. Then their lethal temperature at which 50% of plant were died (LT50) was determined. To estimate FSI (Field Survival Index) index, the 20 genotypes were cultured in a separate experiment on field with 3 replications. The results showed negative significant correlation (-0.601) between field survival index and LT50. Cluster analysis using physiological traits, genotypes of F-A1-1, F-A1-2, F-A2-11, F-GRB-85-5, Sahra, Sahand, Dasht and Makouei were categorized in a distinct group and had a high FSI and low LT50. Makouei cultivar having LT50=-17.66°C and the highest percentage of winter survival in the field, was the most resistant genotype. 10 ISSR markers from 35 primers sequences were selected and used. These 9 ISSR primers produced 50 polymorphic bands. PIC and MI average index for all primers were 0.37 and 1.72 respectively. Cluster analysis of molecular data using Jaccard similarity coefficient categorized the genotypes to four distinct groups. Associations between molecular markers and traits were assessed by multiple regression analysis. Some informative markers related to FSI and also LT50 was determined. So it may be possible to use these markers for selection of resistant lines or genotypes in breeding programs

Mapping of QTLs for frost tolerance and heading time using SSR markers in bread wheat

Selection for complex genetic traits, such as frost tolerance, can be simplified in plant breeding programs when linked markers were detected. The use of microsatellite markers for tagging and mapping important genes or QTLs is a goal in wheat genetic projects. In this study, 200 microsatellite markers were studied and after parental assay, 41 polymorphic SSR markers were used for genotyping of 280 F2 individual plants derived from F1 generation of wheat cross (Norstar× Zagros). The progeny of individual F2 plants were used as F2:3 families for the assessment of LT50 and heading time. Single marker analysis revealed that seven markers with total of 27% of phenotypic variance determination linked to LT50 and five markers linked to the heading time. Two markers that were located on 2B and 5A chromosomes affected both LT50 and heading time significantly. It was assumed, therefore, that someclosely linked QTLs or QTLs with pleiotropic effects govern both traits simultaneously, as the LT50 of F2:3 families were significantly correlated with the heading time of F2:3 families, Thus, it is concluded that later heading time is associated with the higher level of frost tolerance in wheat

Investigation of Seed Storage Proteins in some Wild Wheat Progenitors Using Sdsds-Pageageage and Acidcidcid-Pageageage

Wheat storage proteins accounted for up to 60% of the total grain proteins. They form gluten proteins, which make a visco-elastic network enables dough to be processed into bread, pasta and other products. In order to study genetic variation of wild wheat relatives, electrophoretic patterns of seed storage proteins, the high-molecular-weight glutenins and gliadins from about 12 wild species and some check improved cultivars were fractionated by SDS-PAGE and Acid-PAGE. The results showed some close relationship between T. urartu, T. dicoccum and bread wheat in the case of glutenin and gliadin. Therefore It was speculated that progenitor of A genome of cultivated wheat could be T. urartu strongly. A high level of polymorphism was detected in the glutenin and gliadin subunits of the wild wheat relatives, showing some similarities with cultivated bread wheat, useful breeding perspectives. The electrophoresis proved to be a suiTab. method to discriminate wheat variety and species. Also results of this study confirmed that the genetic variation amongst seed storage proteins of wild relatives were considerable. The wild progenitors are important genetic resources and therefore observed genetic variability could be use in any selection strategies

Assessing Genetic Diversity Based on Gliadin Proteins in Aegilops cylindrica Populations from Northwest of Iran

<span style="font-family: Times New Roman; font-size: small;"> </span><p style="margin: 0in 0in 0pt; text-align: left; line-height: 200%;" class="MsoBodyText2"><span lang="EN-GB" style="color: #221e1f; line-height: 200%; font-size: 10pt;"><span style="font-family: Times New Roman;">Wild wheat progenitors served as a valuable gene pool in breeding perspectives. In this respect, gliadins could be an important tool in assessing genetic variability as protein markers. Thus, genetic diversity of gliadin protein patterns in seventeen populations of </span></span><span lang="EN-GB" style="color: #221e1f; line-height: 200%; font-family: &quot;Garamond Premr Pro&quot;,&quot;serif&quot;; font-size: 10pt; mso-bidi-font-family: &quot;Garamond Premr Pro&quot;; mso-bidi-font-style: italic;">Aegilops cylindrica </span><span style="font-family: Times New Roman;"><span lang="EN-GB" style="color: #221e1f; line-height: 200%; font-size: 10pt;">collected from northwest of Iran were investigated using acid polyacrylamide gel electrophoresis. Results showed that the highest number of bands in the electrophoregrams were related to the ω type of geliadins. Conversely, the lowest number of bands were pertained to the β type of gliadins. Genetic diversity between populations was greater than within population variation. Assessment of total variation for the three gliadin types indicated that the highest total variation was related to β type while, the lowest one was belonged to ω type. Cluster analysis using complete linkage method divided populations into two separated groups in which genetic diversity does not follow from geographical distribution.</span><strong></strong></span></p><span style="font-family: Times New Roman; font-size: small;"> </span

Allelopathic Effects of Sorghum (Sorghum bicolor L.) and Russian Knapweed (Acroptilon repens L.) Aqueous Extract on Seed Germination Indices and Enzyme Activity of Some Field Crops and Weeds

Introduction: The loss of crop yield due to weeds is enormous. Potential yield reductions caused by uncontrolled weed growth throughout a growing season have an estimated range of 45-95%, depending on ecological and climatic conditions. Overusing synthetic herbicides may affect the environmental, human health and food. Furthermore, increasing use of herbicides has resulted in a dramatic increment in the herbicide resistance among weeds, and over 307 weed resistant biotype belonging to 183 species (110 dicots and 73 monocots) have been identified worldwide. Cultivating crops with allelopathic potential can reduce the dependency on synthetic herbicides and increase crop yields. Sorghum (Sorghum bicolor L.) has been reported as one of the most allelopathic crops extensively used as cover and smother crops and also incorporated in the soil for weed suppression. Moreover, Russian knapweed (Acroptilon repens L.) has been shown to produce phytotoxic compounds and plant growth inhibitors, which may contribute to its competitive behavior. The phenomenon of allelopathy has been suggested to be one of the possible alternatives for achieving sustainable weed management. Materials and Methods: In order to evaluate the allelopathic effects of sorghum (Sorghum bicolor L.) and Russian knapweed (Acroptilon repens L.) extract on seed germination indices and enzymatic activity of wheat (Triticum aestivum L.), sugar beet (Beta vulgaris L.), common lambsquarters (Chenopodium album L.) and redroot pigweed (Amaranthus retroflexus L.), an experiment was conducted as factorial experiment based on randomized completely design with three replications in Faculty of Agriculture, University of Maragheh in 2016. The investigated factors were four crops (wheat, sugar beet, common lambsquarters and redroot pigweed), shoot aqueous extract (sorghum and Russian Knapweed) and aqueous extract concentrations at 0 (control), 5, 10 and 20% (m/v). Sorghum and Russian knapweed crops were collected during July 2016. The plants were taken to the laboratory and kept fresh in a refrigerator. In addition, Kato-Noguchi et al., (17) method was followed for extraction. Samples of the above-ground tissues (stems and leaves) of sorghum and Russian knapweed were washed thoroughly with tap water and rinsed with distilled water. They were clipped and then passed through a 1 mm screen before storage in a refrigerator at 2 ℃. Each 50, 100 and 200 g samples was extracted by soaking it in 1 L of distilled water at 24 ℃ during 24 h in a shaker. All extracts were filtered through two layers of cheese cloth to remove fibers. Distilled water was also considered as the control treatment. Results and Discussion: Results indicated that percentage and rate of germination, radicle and plumule length, radicle dry weight, plumule dry weight, seedling dry weight and vigor length index of all crops decreased significantly by increasing aqueous extract concentration of sorghum and knapweed. These results are in agreement with those previously reported that the degree of inhibition increased by increasing extract concentration. Using Russian knapweed aqueous extract, germination percentage was 12.62 percent greater than sorghum aqueous extract. Moreover, inhibitory effect of sorghum aqueous extract on germination rate loss was higher than that of aqueous extract of Russian knapweed. As to field crops, inhibitory effect of sorghum and Russian knapweed extract on sugar beet was higher than wheat. Moreover, the effect of sorghum and knapweed extract on radicle, plumule and seedling fresh weight loss of redroot pigweed and common lambsquarters (weeds) was greater as compared with that on field crops (wheat and sugar beet). Increasing concentration of sorghum extract decreased seed vigor indices of common lambsquarters and redroot pigweed by 83.36 and 87.15% relative to control, respectively. Activity of peroxidase and polyphenoloxidase enzymes was reduced and increased, respectively, as a result of an increment in extract concentration. Batish et al. (7) have demonstrated that parthenin (Parthenium hysterophorus) impairs mung bean growth by affecting respiration, protein content and activities of protease and peroxidase enzymes. The minimum value of plumule and seedling length was observed for redroot pigweed and common lambsquarters weeds with application of 20% aqueous extract of sorghum and Russian knapweed. The values of weed tolerance index (WTI) revealed that redroot pigweed and common lambsquarters were more sensitive to aqueous extract of sorghum and Russian knapweed. The WTI combines several individual measured parameters and ranges between 0 and 1. In this case, a low WTI indicates a high susceptibility to biotic or abiotic stress originated from crop extracts. Conclusions: Our results showed that aqueous extracts of sorghum and Russian knapweed had an inhibitory effect on seed germination indices of wheat, sugar beet, common lambsquarters and redroot pigweed. It can be also concluded that sorghum and Russian knapweed possess weed-suppressing ability and seem to be useful for developing natural herbicides

Changes in fruit yield and photosynthesis parameters in different olive cultivars (Olea europaea L.) under contrasting water regimes

The evergreen tree olive (Olea europaea L.) is the only species of the genus Olea that produces edible fruits with high ecological and economic value. This tree species has developed a series of physiochemical mechanisms to tolerate drought stress and grow under adverse climatic environments. One of these mechanisms is photosynthesis activities, so that as yet little information achieved about the relations between olive production and photosynthetic parameters under drought conditions. An experiment was carried out during two consecutive years (2015–2017) to study the response of 20 different olive tree cultivars (Olea europaea L.) to drought stress. Several parameters like net photosynthetic rate (PN), stomatal conductance (GS), transpiration rate (TE), photosynthetic pigments (total chlorophyll, chlorophyll a, b and carotenoid) and fruit yield were measured. The results of combined analysis of variance for fruit yield and other measured traits showed that year, drought treatment, cultivar main effects and their interactions were highly significant. The results indicated that drought stress reduced all traits, however GS (42.80%), PN (37.21%) and TE (37.17%) significantly affected by drought. Lower reduction in photosynthetic performance (PN, GS and TE) in the cultivar T7 compared to other olive cultivars allowed them to maintain better fruit yield. Principal component analysis (PCA) identified two PCs that accounted for 82.04 and 83.27% of the total variation in photosynthetic parameters under optimal and drought stress conditions, respectively. Taken together, mean comparison, relative changes due to drought and biplot analysis revealed that cultivars ‘T7’, ‘Roghani’, ‘Koroneiki’, ‘Korfolia’ and ‘Abou-satl’ displayed better response against drought stress. According to our results, one olive cultivar namely ‘T7’, could be used in olive breeding programs to improve new high yielding cultivars with drought tolerance for use in the drought-prone environments

Relationship between salt tolerance related physiological traits and protein markers in soybean cultivars (Glycine max L.)

This study was conducted to evaluate the salinity tolerance in seedling stage of soybean (Glycine max L.). Factorial experiment was done based on randomized complete block design with three replicates. 17 soybean genotypes were used in three salinity stress levels (consisting of control, 75 mM and 150 mM NaCl stress). The experiment was carried out in a greenhouse condition and proline, sodium, potassium, and chlorophyll a, chlorophyll b, chlorophyll a/b and total chlorophyll content were examined. To create salinity stress, NaCl was used in the experiment. The results revealed that different salinity stress had significant effects on all traits except for chlorophyll b and chlorophyll a/b. The cluster analysis in the control and at 75 and 150 mM salinity levels classified genotypes into two, two and three groups respectively. In each condition, the dpx and clean genotypes were placed in a group which the average traits were higher than the other genotypes. This can be generalized to the conditions of control as well as 75 and 150 mM salinity stress. Regression analysis showed possible informative loci encoding protein markers that was probable potential for selection strategies for salt weather proved by complementary tests

Assessment of Drought Tolerance Indices and their Relation with ISSR Markers in Bread Wheat (Triticum aestivum L.)

Water stress is one of the most important environmental abiotic stress that reduced crop yield especially in arid and semi arid regions of the world. In order to identifying drought tolerance, 39 cultivars of spring, facultative and winter type wheat varieties were planted as subplots within the irrigation plots (main plots) in a randomized complete block design with three replications in a research filed of Faculty of Agriculture, University of Mohaghegh Ardabili, Iran. In 2/3 continuous irrigation stress level, based on stress susceptibility, geometric mean productivity and harmonic indices, Sepahan, Karaj 3, Bahar and Yavaroos were known as the best varieties; and in 1/3 continuous irrigation stress level, based on the mentioned indices, Hirmand, Bahar, Yavaroos and Marvdasht were the best one. According to biplot resulted from principle coordinate analysis, in 2/3 continuous irrigation Moghan 1, Golestan, Kavir, Maroon, Karkheh, Chanaab, 10, 6, Bahar and Sepahan; and in 1/3 continuous irrigation Golestan, 10, Niknejad, Maroon, Darab, Falat, Arta, Marvdasht, Bahar and Hirmand were identified as the most tolerant cultivars. According to multiple regression analysis in subject of agronomic traits, 43, 33 and 25 informative ISSR markers identified in control, 2/3 and 1/3 continuous irrigation conditions, respectively. Also among these markers, there were significant relationship between P12L3 and P21L3 markers with plant height and spike length; P4L1 and P22L1 markers with flag leaf length; P19L4 markers and number of node; P30L4 markers and awn length; P10L1 and P22L1 with peduncle to plant height ratio in all of stress and non-stress conditions