Selection based on proper selection indices can be one of the most effective methods for indirect selection of yield and yield components, simultaneously. In order to determination of selection index for improvement of maize yield, 60 single cross maize hybrids were planted in two separate experiments (drought stress and normal conditions) based on randomized complete block design (RCBD) with three replications in Torogh agricultural station of Khorasan Razavi agricultural and natural resources research and education center, Mashad, Iran in 2013-2014. Morphological and phenological traits, yield and yield components were recorded. Selection indices were calculated based on results of stepwise regression considering to phenotypc, genotypic and economic values. Based on stepwise regression results in normal condition, physiological maturity, plant height, kernel depth, kernel no./row and tassel length totally could explain 60.68 percent of gain yield variation, then these traits were used to calculate selection index. In drought stress condition, kernel no./row, plant height, ear height, 1000 kernel weight, ear length and leaves no. above ear could explain 63.77 percent of grain yield variation that these traits were used to calculate of selection index. We used 5 optimum selection indices (smith-hazel) and one basic selection index as Pesk-Baker to screen the maize genotypes. The results showed that the relative efficiency of selection index based on yield and expected genetic gain for all of measured traits in selection index 2 was higher than others in both normal and drought stress conditions. Based on grain yield and selection indices, 20 percent of the best genotypes were selected by each selection indices. Based on derived results in normal condition, genotype no. 60 (ksc704 commercial hybrid) were selected by all of  selection indices as the best genotype, but in drought stress condition, different genotypes were selected by different selection indices like genotypes 16 (ME77006/1×K1263/1), 22 (ME77006/1×K1263/1) and  34 (ME78005/2× A679), that these genotypes at least were selected by 2 or 3 selection indices.

Chrysanthemum (Chrysanthemum morifolium) is one of the most important ornamental plants which plays a significant role in the development of gardening industry in the world. The knowledge of genetic diversity is one of the prerequisite criteria for Chrysanthemum breeding with important economic goals. Molecular markers have a significant share in elucidation of inter and intra species genetic diversity. To this end, genetic diversity of a number of Iranian cultivars was molecularly investigated by sequencing a part of rDNA, using ITS4 and ITS5 primers. Genetic distance between Chrysanthemum cultivars ranged from 0.05 to 10.15, demonstrating the power of ITS region in revealing the genetic diversity among cultivars of morifolium, suggesting Iranian cultivars have been genetically improved from morifolium species. Genetic diversity assessment of Iranian Chrysanthemum cultivars demonstrated that presumably inter, intra species or even inter population hybridization may have been involved in creating enormous genetic diversity among Chrysanthemum cultivars.

This experiment was conducted to evaluate genetic diversity in 72 peanut accessions (Arachis hypogaea L.), which introduced from seed bank of Australia in training and seed production research center of oilseeds company, Iran. Twelve major morphological traits recorded during 2013 growing season using a randomized complete block design with three replications. The results showed that the difference between genotypes for all traits was significant. In addition, coefficient of phenotypic variation was greater than coefficient of genotypic variation for all traits, indicating the effect of environment on recorded traits. The broad-sense heritability ranged from 80.25% (for seed width) to 99.54% (for 100 seed weight) and was 96.85% for grain yield. The highest phenotypic and genotypic coefficients of variation obtained for the pod weight, thus, it is possible to improve this trait by selection method and this trait could use as a selection index to improve grain yield. Genetic correlation indicated a high significant correlation between grain yield with grain weight and pod yield. The studied genotypes divided to four groups by cluster analysis based on Ward method.

Dehydration is the most important limiting factor in agricultural production in arid and semi-arid regions, and water shortages (especially at the reproductive stages) due to lack of precipitation and unequal distribution are inappropriate for limiting the yield. In this research, cross between the Gasspard cultivar (dehydrated susceptible parent) and DN11 line (resistant parent) was performed. F₁, F₂, F₃, BC₁ and BC₂ generations along with parents, were planted in a randomized complete blocks design with three replications in normal and water deficit conditions for two consecutive years. Physiological traits were measured for single plant samples. Weighted analysis of variance showed that water deficit stress caused significant decrease in flag leaf area and unsignificant decrease in stomatal conductance. Generation mean analysis for Chlorophyll index was accompanied by different results in terms of regression fitted models for each environment, but for stomatal conductance, the results of the generation mean analysis were the same in both environments. In addition to additive and dominant effects, epistatic interaction effects also played role in the inheritance of all studied traits. Most of these effects were double-effects. In flag leaf area, additive, additive × dominant and dominant × dominant effects were involved in inheritance. In water relative content, in addition to these effects, dominant effect was also involved in inheritance. Generations variance analysis showed that the gene action was additive for relative water content, dominant for flag leaf area and over dominant (in both conditions) for stomatal conductance. The gene action for Chlorophyll index under stress and normal conditions were over dominant and additive respectively.

Protection of food security is one of the basic priorities of any country, which is achieved through the development and introduction of new, high-yielding and stress-resistant crop varieties. Considering the wide range of usage; human nutrition, livestock and poultry nutrition as well as use in industrial products production, maize is of special importance in agricultural development programs. To improve a trait with complex behavior and low heritability, indirect selection by other traits or a suitable index developed based on several traits can be used. In this research, 86 maize genotypes were cultivated in the form of randomized complete block design with three replications in the field in the Faculty of Agriculture, Urmia University under two normal and salt stress conditions. The measurement of the traits was done from the tassel appearance to kernel physiological maturity. In order to speed up genotype selection and increase the acuracy of selecting high yielding genotypes, four selection indices including Smith- Hazel, Pasek- Baker, Brim and Robinson were used and calculated. The results of present study revealed that selection based on the Smith- Hazel index with the highest selection efficiency (∆H) will increase the grain yield in normal and grain yield and plant height in salt stress conditions. This index, with its high correlation with the breeding value is introduced as a superior index. Based on this index, R59 and 6*/88 genotypes were introduced as the superior genotypes under normal and salt stress conditions, respectively. Nonetheless, these genotypes were recognized as the best genotypes considering the results of all other investigated indices. Identifying and introducing genotypes tolerant to salinity stress is of particular importance due to the expansion of saline lands and the limitation of access to water suitable for irrigation. Based on the above results, 6*/88 genotype is recommended for the development of promising hybrids for cultivation in areas with water or saline soil.