Six Holstein cows (120±20 d in milk) were used in a 3x3 replicated Latin square design to investigate the effect of different particle sizes of ground barley grain on digestibility, degradation rate and lactation performance. Geometric mean diameters of the barley particles were 0.94, 1.93 and 2.90 mm for treatments 1, 2 and 3, respectively. Diets were only different in barley particle size and all cows received diets containing 40% corn silage and 60% concentrate (DM basis) composed of 50% ground barley. The differences among dry matter intake (DMI), milk fat percentage, milk total solid percentage, daily fat yield, dry matter digestibility, urinary and ruminal pH, daily body weight change, and fecal particle size distribution were not significant. Treatment 3 caused a decrease (P<0.05) in milk protein percentage, daily milk yield and fecal pH compared to treatments 1 and 2; no other treatment differences were significant. With increasing barley particle size, fecal dry matter was increased but daily milk protein yield was decreased (P<0.05). Significant differences (P<0.05) in 4% FCM, 4% FCM/DMI daily, milk lactose yield, daily total solids yield and organic matter digestibility were observed between treatments 1 and 3. No other treatment effects were observed significant. The soluble fraction, the potential degradable fraction, ruminal degradation rate and the effective degradability of dry matter increased linearly for treatments 1, 2 and 3, respectively. It is concluded that fine grinding of barley (0.94 mm) which is commonly used on dairy farms improved OM digestibility, milk yield, milk protein percentage and production and would be recommended for feeding conditions similar to those of the present experiment.

To identify the QTLs affecting grain weight and yield, 148 doubled-haploid (DH) population derived from a cross between Clipper (high yield) and Sahara3771 (low yield) were screened under controlled conditions. The experiment was conducted in CRD with 3 replications. The new 30 ISSR marker loci were added to a backbone of 466 loci on the Clipper × Sahara DH linkage map. The map spanned 1460 centimorgans (cM) and had a mean density of 2 loci per 3 cM. The QTL analysis led to identification of 5 QTLs on 2H, 4H, 5H and 6H chromosomes for grain yield. These QTLs could explain 57% of the total phenotypic variation, and the QTL on chromosome 2H (ksuF2-mwg892) with 20% had the largest effect. For grain weight, 3 QTLs were identified, and the QTL on 2H could explain 69% of total phenotypic variation. The identification of QTLs with large effects on grain weight and yield illustrates the usefulness of molecular markers in gene mapping and suggest that marker-assisted selection will be feasible in the near future in barley breeding programs.

In order to evaluate morphological and agronomic traits in 40 barley lines, an experiment was conducted using completely randomized block design with three replications. Significant differences were observed among lines with respect to all the traits except harvest index and number of infertile tiller indicating high genetic diversity in the studied materials. Lines number 10, 13, 21, 22, 23, 25, 27 and 31 were superior considering grain yield and most of the measured traits. Significant and positive correlations were found between grain yield and biomass, number of fertile and infertile tiller, harvest index, plant height and spike length. In multiple regression analysis, spike length, awn length, 1000 grain weight, biomass and fertile tillers were entered in the final model. In the path analysis based on multiple regression analysis, grain yield was considered as dependent variable and number of fertile tiller, biomass, 100 grains weight, spike length and own length as independent variable. The highest direct and positive effect on grain yield was attributed by biomass and maximum indirect effect was observed for number of fertile litter via biomass.

To examine the response of spring barley genotypes to terminal drought stress a randomized complete block experiment with 17 lines and two control varieties in stress conditions (after heading) and non-drought stress as separate four replicates in cropping year of 89-1388 was conducted in Mahabad region. The results from the combined analyses showed that the interaction between test conditions and the cultivars for all characters except the period of grain filling and 1000-kernel weight was insignificant. There was also a meaningful difference among the whole cultivars, from traits point of view, except 1000-kernel weight. The results showed that drought in the ending period of the season, plant height (5/8%), time of maturity (6/6%), peduncle length (25/2%), number of grains per spike (18/2%), spike unit area (11/5%), yield (21%) and their biological functions (22/5%) reduced.Lines SLB39, Matnan-01 and Birlik-1/4 with an average yield of two terms, respectively, with 04/4, 9/3 and 3/4 tons per hectare demonstrated superiority over other lines. Line Birlik-1/4 in both normal and stress conditions was the highest figure compared to the first control (Sayed tajaddin) (29/7%) than the second control varieties (Chaldoran) (40/6%) had a boosting performance. Positive and significant correlation index arithmetic mean, geometric mean, harmonic mean, stress tolerance and grain yield in both normal and stress conditions showed that these indices could identify drought tolerant genotypes and environmental conditions applied to both products so that the lines of these indices were superior. Using cluster analysis method based on stress indices in two groups of lines the lines, were sensitive to drought tolerant SLB39, Matnan-01 and Birlik-1/4 in the drought tolerant lines.

Missing values in a data set is a widely investigated problem. In this study, we propose the use of support variables that are closely associated with the variable of interest for the imputation of missing values. Level of association or relationship between the variable of interest and support variables is determined before they are included in the imputation process. In this study, the barley (Hordeum vulgare) grain yield in the semi-arid conditions of Cyprus was used as a case study. Monthly rain, monthly average temperature, and soil organic matter ratio were selected as support variables to be used.Multivariate regression employing support variables, bivariate, kernel regression and Markov Chain Monte Carlo techniques were employed for the imputation of missing values. Obtained results indicated a better performance using multivariate regression with support variables, compared with those obtained from other methods.

For studying genetic variation for grain filling rate and grain filling period and relationship with grain yield, 10 barleygenotype: Bomi, Torkaman, Eize, Siah, Sahra, 1-yeknavakht, 14G, 11G, 5G and 15G, cultivars, introduced by Golestsn agriculture research centre, Were studied in randomized complete block design at 4 replication at 84-85.were studied.This genotype varied for both rate and duration grain filling parameter and had significant difference. Torkaman had maximum grain filling rate and minimum was for 1-yeknavakht.the average of grain filling rate was 1.59 mg/day and average of grain filling duration was 29.8 days. Positive correlation between grain filling rate and duration with grain yield showed that, they increased from low yield genotype to high yield.14G had maximum and Torkaman had minimum grain filling duration. Negative no significant correlation between grain filling rate and grain filling duration.14G showed that have higher grain yield than other genotype and with receive lower GDD, achieved to the physiological maturity

For studying genetic variation for grain filling rate and grain filling period  and relationship with grain yield, 10 barley genotype: Bomi, Torkaman, Eize, Siah, Sahra,1-yeknavakht, 14G, 11G, 5G and 15G, cultivars ,introduced by Golestsn agriculture research centre, Were studied in randomized complete block design at 4 replication at 84-85.were studied. This genotype varied for both rate and duration grain filling parameter and had significant difference. Torkaman had maximum grain filling rate and minimum was for 1-yeknavakht.the average of grain filling rate was 1.59 mg/day and average of grain filling duration was 29.8 days. Positive correlation between grain filling rate and duration with grain yield showed that, they increased from low yield genotype to high yield.14G had maximum and Torkaman had minimum grain filling duration. Negative no significant correlation between grain filling rate and grain filling duration.14G showed that have higher grain yield than other genotype and with receive lower GDD, achieved to the physiological maturity