JOURNAL OF CROP BREEDING
Year:2020 | Volume:12 | Issue:34|Papers Count:20

The aim of this study was to determine the haplotype groups and their relationship with phenotypic traits in order to obtain the alleles associated with desirable agronomic characteristics in bread wheat. For this purpose, 34 local bread wheat genotypes belong to the Middle East region along with Chinese Spring variety (reference genotype) were cultivated in the form of augmented design and evaluated based on their 12 phenotypic traits. The results of descriptive statistics showed that awn length and day to flowering had the highest and lowest phenotypic coefficient of variation respectively. Ten microsatellite markers were used to investigate the haplotype variation of QTLs associated with phenotypic traits located on wheat chromosomes 4B. The mean of polymorphic alleles, polymorphic information content (PIC) and resolving power (RP) were 4. 5, 0. 29 and 1. 58, respectively. The genotypes were classified into 21 haplotype groups according to the allelic comparison with the reference genotype on chromosome 4B. In order to investigate the relationship between traits and markers, analysis of variance was performed on the basis of completely randomized design with unequal numbers of replications for each marker. In general, of the 12 traits studied, there was a statistically significant relationship for four traits. According to the results of microsatellite markers on chromosome 4B, there was a linkage between grain width, number of grains per spike and flag leaf width with Xgwm888-4B marker, number of spikelets per spike with Xgwm891-4B marker, grain width and number of grains per spike with Xgwm898-4B marker. For the three phenotypic traits, a specific allele was simultaneously introduced to Xgwm888-4B marker. If the breeders is interested in genotype selection that simultaneously have three desirable characteristics such as more grain width and more number of grain per spike, as well as increase of leaf area index through flag leaf width, they can use an allele-specific (199 bp) of Xgwm888-4B marker.

In order to evaluate the genetic diversity in 115 rice mutant genotypes of Tarom Jalodar, a randomized complete block design with three replications was conducted at Sari Agricultural Sciences and Natural Resources University. Eleven quantitative traits were evaluated. Analysis of variance showed that there is a significant difference between the genotypes for the morphological traits. The correlation coefficients between traits showed that flag leaf width, number of tillers, number of grains and 100-grain weight had a positive and significant correlation with grain yield. Based on cluster analysis, rice genotypes were divided into three groups. Stepwise regression analysis showed that panicle length, 100-grain weight and number of unfilled grain explain 58. 9 % of variation of yield Results of path analysis showed that the most direct and positive effects obtain from number of tillers (0. 59) and 100-grain weight (0. 37). Results of the main principle component analysis (PCA) revealed that the four main components justify 70. 15% of the total data variation. In general, the results showed that genotypes 109, 64 and 75, due to the more number of tillers, higher length of panicle, the more100-grain weight and less number of unfilled grain were chosen as desirable genotypes, they can be used in the following program.

Salinity is one of the most important abiotic stresses that can affect the yield of wheat. It is important to study the mechanisms of tolerance to salinity in crops and their ancestors. The purpose of this project was to investigate the responsive protein spots to salt stress in tolerant population. In this research, five diploid wheat population of T. boeoticum (A1, A10, B3, B4, C5) were grown in greenhouse as factorial experiment in a completely randomized design with three replications. Salinity was applied at two levels of zero and 150 mM. Then, the traits of shoot and root height, fresh and dry shoot weights, chlorophyll a, b, total carotenoids and total protein content were measured. Total protein was extracted using TCA / acetone method. The proteins were separated in the first dimension by isoelectric point using IPGs pH 4-7 followed by SDS-PAGE as the second dimension using molecular weight. The results of physiological data analysis showed that for fresh and dry shoot weights and total protein content, the interaction effect of the population*salinity was significant. For the two traits of fresh weight and total protein, the population of B4 had the highest average. Two-dimensional electrophoresis gel analysis revealed 205 repetitive spots. Out of these, 7 spots showed upregulation and 7 spots downregulation. Identified proteins include proteins involved in the cell wall, photosynthesis, energy metabolism, chromatin-related proteins, chaperones, proteolytic, in the removal of reactive oxygen species, in repairing damaged proteins and in the transmission of the message. These results can be used to improve wheat cultivars.

Salinity stress has an important role in reducing crop production. There is a possibility of cultivar diversity use in desirable traits selection under stress. This research was carried out in order to test of different salinity level on yield of barley (Hordeum Volgar L. ) genotypes, in the split plot experiment on the base of Randomized Completely Block design in 3 replications. Salinity treatment involved 5 levels: S1 (control)=EC 4. 5 ds/m, S2=EC 7. 5 ds/m, S3=EC 10. 5 ds/m, S4=EC 13. 5 ds/m and S5=EC 16. 5 ds/m as main plot and subplots were 9 genotype involved promising lines and varieties. The effects of Salinity treatments studied by sampling on yield of genotypes and using stability parameters. That based on Shukla stability variance, Wricke ecovalance and Eberhart and Russell regression model the STW82153, MBS8715 and Valfajr genotypes and based on Romero environmental variance the MBS8712 genotype exhibited the most stability. The best performance in all salinity levels was shown by genotypes STW82153, MBS8715, ESBYTM8910 and Valfajr. Genotype MBS8712 showed the least change with increasing salt concentration and with the improvement of environmental conditions, genotypes MBS8715 and WB7910 had the highest production capacity. The results indicated that used stability parameters would be useful for simultaneously selecting for high yield and stability under salinity conditions.

Accurate interpretation of the genotype-environment interaction provides the ability to the identification of stable genotypes for breeders. To study genotype-environment interaction, 12 genotypes of sunflower were cultivated in five regions including Arak, Birjand, Kashmar, Karaj and Shiraz were evaluated in the 2015-2016 growing season. To do yield stability analysis the graphical GGE biplot method was used. The results showed that the Record and Zaria genotypes in Karaj, SHF81-90 and Sor genotypes in Birjand and Kashmar, Gabur genotype in Shiraz and Armaverski in Arak were stable with the highest kernel yield. Environments of Birjand, Kashmar, Karaj, Arak and Shiraz were the best environments respectively. Genotypes rankings based on the ideal cultivar and also cultivars ranking graph based on the mean yield and stability revealed that genotypes SHF81-90, Lakomka and Sor were the best and stable genotypes. The relationship view of biplot indicated a high correlation between environments of Karaj, Kashmar and Birjand. Biplot graphical method determined four mega-environments: Karaj as the first mega-environment, Kashmar and Birjand as the second mega-environments, Shiraz as the third mega-environment and Arak as the fourth mega-environment.

Caper bush (Capparis spinosa L. ), is a perennial medicinal plant of hot and dry climates that grows in the summer. This plant contains important compounds such as flavonoids, terpenes, alkaloids, glycosides, and glycosinolates. Despite the ever-increasing need for the mass reproduction of this plant, there is little information about the methods of its proliferation. In this research, the cotyledon leaf, leaf, bud, stamen, cotyledon upper axis, root, petal, sepal, and node explants were cultured in MS medium containing KIN, NAA, BAP and IBA hormones at different concentrations in order to direct regeneration of seedlings for shoot. Experiment was conducted to identify the best media for production of shoots and roots in vitro cultivation of caper different explants. In present experiment, except node explants, none of the other explants were regenerated, and the regeneration from node explants were achieved in 5 to 8 weeks, where MS medium containing 2 mg/L BAP and MS medium containing 1 mg/L NAA were the best medium for production of shoots and rooting, respectively. Considering the importance of Capparis spinose as medicinal plant and its difficulty to reproduction by seed, use of these media and node explant are recommended to production of this medicinal plant under in vitro culture conditions.

Fusarium head blight disease caused by Fusarium graminearum is one of the most important and destructive diseases of wheat in warm and humid zone. The importance of this disease is to reduce the yield and accumulation of mycotoxin in the harvested grains from infected heads, which are dangerous to humans and animals. Production of resistant varieties with using genetic resistance sources is the most effective method of sustainable control of this disease. To study the inheritance of resistance-controlling genes in cv. Morvarid, the resistant cv. Morvarid, was done cross with susceptible cv. Falat, and generations of F1, F2, BC1 and BC2 were produced. Resistance components include the area under the disease progress curve (AUDPC), the relative area under the disease progress curve (rAUDPC) and the final severity infection (FSI), was recorded. Parents and generations were planted in a randomized complete block design with three replications. Parents and generations were inoculated at the adult plant stage by a mixture of Fusarium head blight isolats at the Gorgan Research Station. Analysis of variance showed significant differences among generations for measured traits. The average degree of dominance was approximately equal to unit (one) for all traits, indicating dominance genetic control. Epistasis interaction effects of additive × dominance, dominance × dominance were significant for the all traits. Broad-sense (0. 45-0. 56) and narrow-sense (0. 37-0. 48) heritability was estimated as moderate, indicating the important role of additive effects and dominance in genetic control of these traits. The number of segregating genes for measured traits 1 to 7 genes was estimated. Since Morvarid Cv. is currently the most commercially resistant cultivar to Fusarium head blight, due to the additive effects of resistance genes in controlling these traits, selection can be applied to improve these traits in the early generations of this cultivar.

Growing degree-days (GDD) is considered as an alternative indicator for counting calendar days in studying of crop phenology stages. In the current study, genetic diversity of 86 Iranian wheat cultivars and 184 landraces were investiagted based on the phenological stages (day to booting, day to flowering, day to maturity and GDD of these stages) along with grain filling period, thousand grain weight and grain yield during 2013-2014 growing seasons in augmented design with 3 control cultivars (Azar, Navid and Pishtaz) in 6 incomplete blocks in Agronomy and Plant Breeding research filed, University of Tehran. The results illustrated that there is a significant difference between cultivars and landraces, so that the cultivars had higher yield and less grain filling period than the landraces. On the other hand, the results indicated that the genotypes with different growth habits have a significant difference in terms of most of the phenological traits which it could be useful either in directly or indirectly selection for increasing the length of the grain filling period along with grain yield. Since the diversity of phenological traits were higher in landraces, they can be a valuable source for selection to improving these traits. Finally, due to the importance of the phenological stages and GDD index, it is recommended that these traits also consider as well as yield and yield components in order to obtain more accurate results.

Due to decreasing annual rainfall and increasing drought and temperature, creating tolerant and high yield potential cultivars in sugar beet is very important for breeders. For this purpose, to investigate the effect of drought stress on yield and morphological traits of sugar beet and the relationship between these traits with yield in greenhouse conditions, 140 sugar beet genotypes under greenhouse conditions in Karaj Sugar Beet center in 2015 were evaluated for yield traits. The results showed that the effect of genotype was significant for all traits except of leaf area and relative water content, indicating that there was different among genotypes. Drought stress decreased all traits but this effect was not significant on root dry weight, shoot dry weight and total dry weight. Also, petiole length had a positive and significant correlation with root and shoot dry weight and root length in drought condition but under normal condition, no significant correlation observed. It seems that this traits may be a criterion for selection of resistant genotypes under drought stress.

In order to study the genetic variation and selection of high yielding barley lines with desirable agronomic traits, 108 pure lines in the non-repeating Augment design with four controls in three blocks were evaluated using the selection index of ideal genotype (SIIG). The experiment was evaluated in the farm of Darab Agricultural and Natural Resources Research Station in the period of 2017-18. The results of the SIIG index indicated that Lines No. 64, 8, 33, 113, 119 and 34 with the high value of SIIG (0. 770, 0. 746, 0. 744, 0. 712, 0. 705 and 0. 705, repectively) were superior genotypes and lines number 44 and 116 with the lowest SIIG (0. 149) were the weakest lines in this study. In order to evaluate the efficiency of SIIG index in selecting the best lines for grain yield, thousand kernal weight, plant height, days to heading and days to maturity, lines were grouped according to SIIG index in 6 categories. The results showed that as the amount of SIIG index decreased, yield, 1000 grain weight and plant height were also decreased, but there was no significant change in the days to flowering and days to maturity. The results of grouping of lines based on SIIG showed that the average grain yield of groups 1 and 2 were higher than the average yield of the all controls. Also, mean yields of groups 4, 5 and 6 were lower than all four control genotypes. Finally, lines number 64, 8, 33, 113, 119 and 34 )Group I) and lines number 87, 65, 85, 115, 32, 6, 86, 2, 15, 13, 9, 57, 62, 63, 28, 14, 89, 94 and 16 (Group 2) and Lines number 22, 10, 46, 55, 114, 96, 104 and 25 of (Group 3) were the best Lines and can be used for further testing, including adaptation tests in tropical areas, especially Darab. Also, line 113 was the top two-row line in this study.

Purslane (Portulaca oleracea) is one of the most widely used medicinal plants in the world. To investigate the genetic variation in the second generation (M2) of purslane lines, a nested experimental design with two replications was carried out at the research farm of Shahed University, Faculty of Agriculture during 2017-8. Experimental treatments were included M2 lines treated with dimethyl sulfate (DMS) at 0, 0. 08, 0. 1, 0. 12 and 0. 14 % concentrations. The studied traits were included plant height (PH), number of branched stem(NBS), stem diameter (SD), stem fresh weight (SFW), stem dry weight (SDW), SDW/SFW, leaf fresh weight (LFW), leaf dry weight (LDW), LDW/LFW, plant fresh weight (PFW), plant dry weight (PDW), PDW/PFW, leaf length (LL), leaf width (LW), leaf shape (LS), number of capsules (NC), chlorophyll content, leaf area, hectoliters. Although the differences among DMS concentrations were significant at the 1% level in multiple variance analysis, but at simple variance analysis it was significant only for traits such as PH, NBS, SD, SFW, SDW, LFW, LL and LW. The maximum amount of traits such as SD, SFW, SDW, NC, LDW/LFW, PFW and LS was observed at the concentration of 1%. Among the 190 incomplete correlation coefficients, 28 were significant (15%) while this value was 58% in the Pearson correlation coefficient. In factor analysis, 19 variables were reduced to 6 factors, which explained 71. 86% of the data variation. In path analysis with replications data, the direct effect of SFW on PFW was higher than the indirect effect, while this trend was reversed on LFW. In path analysis with mean of replications, the maximum indirect effect on PFW was from LFW and LDW/LFW through SFW.

In order to study grouping of advanced spring wheat genotypes under non-stress and drought stress conditions (stop irrigation in the stage of the emergence of 50% inflorescence of each experimental unit), 28 genotypes were evaluated in 2016-2017 and 2017-2018 cropping yearin two separate experiments with a randomized complete block design with three replications in the research field of Islamic Azad University of Tabriz. Combined analysis of variance revealed a statistically significant difference between studied genotypes for all traits (P<0. 01). Genotype × condition interaction was significant for seed yield, number of seeds in spike, plant height, harvest index in 5% probability level and 1000 seed weight and biomass in 1% probability level. The results of the present study showed that studied genotypes had different reactions in different environmental conditions for these traits. However, Genotype × condition interaction was not significant for number of spike, length of spike and length of peduncle. Cluster analysis classified genotypes based on all studied traits into two groups under non-stress and drought stress conditions. Results of the discrimination function analysis confirmed this grouping. Under nonstress condition the first group includes Darya, Shiroodi, ERWYT-94-4, Roshan, ERWYT-94-7, URBWYT-94-2, URBWYT-94-4 genotypes, which mean of all traits except harvest index were higher than the total mean. Overall, results indicate that the first group was the superior group. Under drought stress condition the second group includes Darya, Shiroodi, Aftab, URBWYT-94-3, ERWYT-94-4, URBWYT-94-6, Roshan, ERWYT-94-7, URBWYT-94-7, URBWYT-94-8, URBWYT-94-9, URBWYT-94-10, URBWYT-94-2; URBWYT-94-4, which mean of all traits were higher than the total mean. The best genotypes for both cluster analyses under both non-stress and drought stress conditions, were genotypes of Darya, Shiroudi, Roshan, URBWYT-94-2, URBWYT-94-4, ERWYT-94-4 and ERWYT-94-7.

Fusarium ear rot is one of the most common diseases in the most cornfields of the world which control of disease using chemical and agronomic methods is often ineffective and increases production costs, that is because hosting resistance is the best sustainable and tolerable way to reduce losses. For this purpose, an experiment was carried out at the Agricultural Research Station of Gorgan, 2015-2016, complete diallel crosses and back crosses were produced by crossing of five tolerant and susceptible crosses and then evaluating cross resistance. After evaluating the disease severity, results showed that there were significant differences among different crosses for the desired traits and then significant effects of general combining ability and specific combining ability indicated the role of dominance and additive effects in controlling the disease. The crosses were divided into three groups: semi-resistant, semi-susceptible and susceptible. Cluster analysis included 15 tolerant genotypes in one group with disease severity between 26-32%. The highest number of semi-tolerant hybrids were due to the crossing of two C7 and C5 tolerant genotypes with other genotypes. This suggests that these two lines could be good sources for the development of crosses compounds susceptible to corn fusarium ear rot.

Water deficiency causes crop yield loss, especially in flowering and pollination stage. This investigation was conducted out as a field experiment in Agriculture Faculty of University of Mohaghegh Ardabili in 2018, to evaluate drought tolerance of ecotypes at flowering stage. All plots were arranged in split plots based on a randomized complete block design with three replications. The main factor of experiment included two irrigation levels (full irrigation and irrigation until flowering stage) and sub-factor consisted of 10 different ecotypes of black cumin. Analysis of variance showed that the effect of drought stress on all studied traits except flowering date was significant. Drought stress significantly reduced the mean of all traits except flowering date and oil percentage. Comparison of mean data showed that the highest grain yield and oil content were observed in Semirom and Kazemain ecotypes, respectively. Also, the highest 1000-grain weight was obtained and in Ardestan and Khomeini Shahr ecotypes at full irrigation. Based on the results of cluster analysis under drought stress condition, the studied ecotypes were divided into three groups. Ecotypes of third group including Khomeini Shahr, Semirom, Isfahan, Ardestan and Shahreza had higher yield and yield components than ecotypes in other groups. Therefore, these ecotypes were identified as high yielding and drought tolerant. Also, three-dimensional plots based on stress tolerance index (STI), yield stability index (YSI), yield under full irrigation (Yp) and end-season drought stress (Ys) showed that the ecotypes of Khomeini Shahr, Semirom, Isfahan, Shahreza and Ardestan are considered as superior ecotypes in both conditions.

To verify diversity, relationship between traits, and selection of superior genotypes using the selection index of ideal genotype (SIIG) technique, an experiment was carried out on agricultural land in Tikmeh Dash city, from the province of East Azarbaijan, Iran in 2017-18. In this experiment, 22 autumn canola genotypes were studied in a randomized complete block design (RCBD) for some of agronomy traits. The results showed L963, Okapi and Licord genotypes have the highest yield mean. Also, the traits of the number of pods per plant (NPP), yield and yield of single plant in these genotypes had a high coefficient of phenotypic diversity, which indicates the effect of environment on these traits. Phenotypic and genotypic diversity coefficients the traits of the number of pods per plant (NPP), yield, and single yield (YSP) in all genotypes had high genetic diversity. Heritability was low for the day to flowering (DF), number of pods per main stem (NPMS), and yield traits; however, it was high for the day to pod (DPO) day to ripping index (DRI) and plant height (H) traits. Altogether 65. 69% of the total variation was justified through the 5 factors that had been determined by the factor analysis to the principle component. Based on the SIIG technique, the genotypes SW101, L83, HW101 and 963 with the highest SIIG values (0. 710, 0. 672, 0. 6531 and 0. 6530 respectively) were the best genotypes. On the other hand, Zarfam, Talayeh, 957 and SLMO16 genotypes with the least amount of SIIG value (0. 185, 0. 243, 0. 271 and 0. 272 respectively) were the weakest genotypes for most morphological traits. The genotypes of SW101, L14, L944, Okapi, and L963 both having high SIIG value and high yield, are the best genotype from the point of yield and other morphological traits.

In this research, the genetic diversity of some oriental and water pipe’ s tobacco genotypes was investigated under normal (without Orobanche) and Orobanche stress conditions during 2007-2008 and 2008-2009 at Urmia Tobacco Research Centre with randomized complete block design with three replications. Combined analysis of variance revealed extent genetic variability among the genotypes for most of the studied traits. This suggests that there is high genetic variability among tobacco genotypes for resistance to Orobanche which can be effectively used in biotic resistance breeding programs. A high genotypic coefficient of variation was seen for studied traits especially for FWL and DLYP in normal and Orobanche stress conditions. The highest broad-sense heritability was estimated for FD, NL and PH in both normal and Orobanche stress conditions. The results of the genetic advance calculation showed that the highest genetic advance was related to LAI, APFW, PH and FWL traits. Based on the results of genetic correlation coefficients of traits, positive and significant genetic correlations were observed between DLYP with all studied traits in both normal and Orobanche stress conditions. Cluster analysis classified all tobacco genotypes into four clusters under normal and stress conditions. In Orobanche stress condition, ratings the clusters in view of traits average showed that the second and fourth clusters contain genotypes that are resistant and sensitive to Orobanche stress, respectively. Therefore, by selecting suitable parents from these groups and crossing them, it will be possible to produce segregated populations in Orobanche resistance breeding programs and to make desirable changes in tobacco yield. Results of cluster analysis were confirmed by results of canonical discriminant function results. The principal component analysis identified two components in each condition which explained more than 75 and 73 percent of the total variation in normal and stress conditions, respectively. Genotypes classified in the second cluster can be potentially used in the Orobanche infested areas.

Weeds are a limiting factor in sugarcane cultivation and able to reduce its yield during the growing season. In this study, first, the effect of 2, 4-D plant growth regulators at 6 levels, kinetin (Kin) at two levels and 6-benzyl aminopurine (BAP) at two levels on callus induction, organogenesis and browning of leaf explants of sugarcane (Saccharum officinarum L. ) cultivar 'CP69-1062' was investigated. The results showed that the highest callus induction was observed in MS medium (Murashige and Skoog) containing 2 mg. 2, 4-D with 2 mg. BAP. Explant browning was the highest on MS medium without plant growth regulators and MS medium containing 1 mg. 2, 4-D and 2 mg. BAP. Also in medium with 2 mg. BAP, direct organogenesis was achieved. In the second experiment, calli produced in MS culture medium containing 16 mg. 2, 4-D, 1 mg. Kin and 2 mg. BAP were transferred to regeneration medium containing different concentrations of glyphosate herbicide. The results showed that in regeneration medium without glyphosate, plantlets were induced, but calli affected by the glyphosate herbicide were not able to produce plantlets. In another experiment, calli produced in the optimal culture medium were immersed in the liquid culture medium containing 4 different levels of ethyl methane sulfonate (EMS) for 0, 3, 6, 12, 24, and 48 hours to cause mutations. In an EMS-free control medium, calli were able to produce plantlets at all times, but with increasing concentration and duration of treatment with EMS, plant regeneration was decreased. Then, to select resistant plantlets, glyphosate herbicide was sprayed on them with a concentration of 4%. Of the 20 plants treated with glyphosate, only 1 showed resistance to herbicide.

In order to evaluate the drought stress tolerance of durum wheat genotypes, an experiment was conducted at Gachsaran Dryland Research Center, Iran during 2017-18. A total of 18 durum wheat genotypes were studied in a randomized complete block design with four replications under rainfed and supplementary irrigation conditions. The results of combined analysis of variance showed that supplementary irrigation significantly increased grain yield. In supplementary irrigation condition, the genotypes 16, 17 and 18 and in rain fed condition the genotypes 4, 16 and 17 had the highest grain yield per hectare. The stress tolerance indices were calculated based on yield of genotypes in rain fed and supplementary irrigation conditions. With considering of significant positive correlation between grain yield in the rain fed condition (YS) with relative drought index (RDI), mean productivity index (MP), stress tolerance index (STI), yield index (YI), geometric mean productivity index (GMP), new drought resistance index (DI), improved stress tolerance index (MSTI), non-Stress Environmental Stress Index (SNPI) and harmonic Mean Index (HARM), these indices are suitable for identification of stress tolerant lines. Stress susceptibility index (SSI), yield stability index (YSI), abiotic stress tolerance index (ATI) and stress sensitivity percentage index (SSPI) did not play a significant role in the differentiation of genotypes. On the other hand, there was a significant positive correlation between grain yield in supplemental irrigation with TOL, MP, YI, MSTI, SSPI, ATI, SSI and STI. Grouping of genotypes using cluster analysis method showed that the genotypes were classified into four distinct groups and genotypes 4, 16 and 17 were in the fourth group with the highest tolerance indices compared to the other. Genotypes 7, 8 and 10, which had the lowest yield and also the lowest amount for the most indices, were identified as the most susceptible to drought stress. The results of factor analysis confirmed the above results.

Plants are often exposed to a wide range of abiotic stresses, which have adverse effects on the survival, growth, quality, and quantity of crops. Coldness is one of these stresses that the late spring cold can cause great damages to the crop (cereal) planting during the reproductive period. The purpose of this research was to investigate the effect of spring cold on the physiological traits, associated with stress toleration including proline amino acid, and pigments (chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid) in the reproductive stage. To this end, an experiment was conducted in a controlled condition (greenhouse) with a combined analysis model based on a completely randomized design in four media (control temperature level of +8 C, +2 C, 0 C, and-2 C)for 20 cultivars of barley and three replicationin the Faculty of Agriculture of Tarbiat Modarres University, Iran, in 2016-17. The results of the analysis of variance showed that cold stress levels, cultivar, and interaction of cultivar on cold were significant for all the traits at 1% probability level. Cold-tolerant cultivars had higher levels of proline (Jolgeh cultivar) and plant pigments (Yousef and Nik) at different levels of cold stress. The cluster analysis was performed through the Ward method using the Euclidean distance coefficient to determine the genetic relationships between the studied cultivars, and the studied cultivars were divided into five groups at the control and severe stress (-2 C) levels and tolerated cultivars were grouped together. 12 pairs of microsatellite primers were used to study the genetic diversity in the molecular segment and the average polymorphism content information was estimated as much as 0. 38. The cultivars were grouped through the Dice similarity coefficient as well as cluster analysis via the UPGMA model, and 20 cultivars of barley were divided into 4 groups. The results of correlation analysis through stepwise regression analysis showed a high correlation (highest coefficient of explanation) for Bmag0337 indicator with proline (R2=0. 43), Bmac0518 indicator with chlorophyll a and total chlorophyll (R2=0. 29), EBmac0602 indicator with chlorophyll b (R2=0. 15), and Bmag0375 (R2=0. 44) with carotenoid trait.

In order to investigate the metabolic responses of rice root under salinity stress at seedling stage, an experiment was conducted at greenhouse with five replications as factorial in a completely randomized design including two salinity levels (0 and 150 mM), two sampling times (6h and 54h) and two genotypes CSR28 (tolerant) and IR28 (susceptible). In total, GCMS analysis identified 36 primary metabolites (including 18 amino acids, five sugars and sugar alcohols and 13 organic acids). The amino acids showed the highest accumulation in facing to high salinity. Moreover, the genotypes showed more differences after the long-term of salinity treatment and the tolerant genotype CSR28 had the highest accumulation of amino acids suggesting the role of osmotic adjustment mechanisms on inducing of salt-tolerance. Among the sugars, raffinose and myoinositol had more accumulation specifically in the tolerant genotype at 54h time point, indicating their antioxidant activity. Generally, these findings emphasized the importance of identification and dissection of metabolic pathways for understanding of the salttolerance molecular mechanisms and consequently improving the development of salt-tolerant varieties in rice.