The purpose of this research was to study the relationships between surface nanomechanical properties and agronomic traits in different sugar beet varieties (Beta vulgaris spp.). Agronomic traits were related to the indicators of seed germination stage and resistance to rhizomania; and in correspondence, a group of nanomechanical traits of inner testa of seeds were examined using an atomic force microscope. The results of parametric and non-parametric correlation analysis between agronomic and nanomechanical traits showed that the single bud wet weight had a significant negative and positive relationship with, respectively, lower surface friction and adhesion of the inner testa. Similarly, thousand shell weight had a negative correlation with upper surface elasticity, and also seed vigor had a positive correlation with upper surface friction. Spearman's rho correlation coefficient showed that resistance to rhizomania also had a significant positive correlation with the upper surface adhesion of the inner testa. Three canonical variables between the two groups of physiological and nanomechanical traits were significant (r1= 0.972 and DF= 66; r2= 0.924 and DF= 50; r3= 0.839 and DF= 36). These traits have a kind of cause-and-effect relationship and, therefore, have the potential to be used for breeding programs and plant systematic studies.

In order to induce of genetic variation and selection of genotypes with desirable traits، Seeds of three varieties of Rapeseed Sarigol (PF)، RGS003 and Zarfam were treated with different doses of gamma ray 500، 700 and 900 Gy. To confirm the stability of the induced genetic traits، 66 mutant lines from M4 generation were studied in a randomized complete block design with three replications. Twenty-two selected lines of M5 generation were evaluated of traits such as height، number of siliqua per plant، number of seeds per siliqua، mean siliqua length، seed 1000 weight and yield. The results of analysis variance that that there are showed significant differences the lines in all the traits studied. The highest coefficient of variation was obtained for the number of siliqua per branch (29/57 percent). Trait mean comparison of experiment lines with control showed that siliqua length، seed 1000 weight and yield was significantly higher than the control varieties in Zar-16 and Zar-20 mutant lines. Because of these lines had not different with control varieties for the other traits were considered as superior lines.

In order to investigate the relationship between agronomic and physiological characteristics of wheat genotypes, a research was conducted with 24 genotypes based on randomized complete blocks design with four replications in the 2018-19 and 2019-20 crop seasons under dryland conditions. Photosynthesis rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, mesophyll conductance, days to heading, days to physiological maturity, plant height, 1000-kernel weight and grain yield were measured during the growing season. Simple correlation analysis showed significant relationship between yield and physiological traits during the two years of the experiment, Also, canonical correlation analysis between physiological traits and agronomic traits showed a significant canonical correlation in the first year (r = 0.64) and the second year (r = 0.64). Correlation of traits with their canonical variables and the opposite canonical variables during two years of experiment showed that all physiological traits have a positive and significant relationship with each other and their canonical variables. The relationship between days to heading with the agronomic and physiological traits was negative and significant over the two years of experiment, but the results showed a positive and significant relationship between grain yield with the agronomic and physiological traits during the two years of the experiment. Also, in the second year of the experiment, the relationship between plant height and the agronomic and physiological traits was assessed as positive and significant. Therefore, genotypes with a shorter growth period and a longer grain-filling period can be recommended for obtaining maximum grain yield under dryland conditions.

The genetic structure of agronomic traits has the most important role in determination of breeding methodology. Generation means analysis and QTL mapping refers to effective methods for determination of gene type and action. In order to investigate the genetic structure of agronomic traits of Gharib × Khazar via means analysis, six basic generations in three replications as randomized complete block design were cultivated at Gonbad Higher Education Center in 2008. At the same time, in order to map agronomic traits, 20 plants of 192 F3 families and parents were planted. The results showed gene controlling of plant height, panicle length and biomass indicated over dominance, grain number, branches number, days to flowering, panicle extraction and flag leaf length showed partial dominance. Significant additive effects were detected for grain number, branches number, days to heading, plant height and panicle extraction. Therefore, the selection method is useful for improving these traits. The three paramedic models were detected for branches number, plant height, panicle length, panicle extraction, days to heading, panicle extraction and flag leaf length and width. Mapping of agronomic traits showed that qHD-1b, qPL-12, qNP-2, qDWS-8, qWFL7, qWP1, qWP-11a and qWP11b explained more then 20 percent of total phenotypic variation. The comparison of the two methods showed that, with the aid of selection for some QTLs such as qHD1b, can be used for decreasing days.

Genetic diversity is one of principle factors to succeed in breeding programs, so its determination is vital in the using of plant genetic resources. With the aim of evaluation of genetic diversity among safflower landraces, 20 lines (14 Iranian and 6 foreign lines) were studied for phenotypic and genotypic variations using agro-morphological traits and RAPD markers. Field study was conducted in RCBD design with three replications in 2007-08. The results of analyses of variance showed that there was significant difference among the studied lines for all agro-morphological traits characters except number of heads. Plant height, number of head and seed germination had significantly positive correlation with grain yield. These traits also showed the most direct positive effects on yield and could explain 43% of total variation of grain yield. Out of 20 primers used in RAPD analysis, 12 primers were polymorphic and produced 104 clear polymorphic bands with average 8.7 band for each primer. Cluster analyses, based on both morphological traits and molecular data, classified the lines into four groups, however, there was not great similarities between two clusters (7.7%). It can be concluded that RAPD is a suitable technique to determine genetic diversity among studied safflower lines. The existence of the great genotypic variation among safflower landraces can be exploited in breeding programs in rainfed area of Iran.

Identification of molecular markers associated with quantitative and qualitative traits can facilitate selection for these traits in breeding programs. This study was designed to identify AFLP markers associated with agronomic and fiber traits using an F4 population derived from interspecific cross between Gossypium hirsutum and G. barbadense. Seeds were grown in the field and plants were scored for eleven agronomic and fiber quality traits. Correlation analysis between AFLP markers and traits indicated that 19 and 14 markers were significantly associated positively or negatively with fiber and agronomic traits. Only markers which have been correlated with a specific traits significantly were used for stepwise multiple regression analysis. Associated markers explained from 6. 2% (for lint weight، seed weight and micronaire) to 43% (for 2. 5% span length) of the total variation available for different individual traits. Results suggest that these AFLP markers could be used for predicting and selecting desirable cotton germplasm to improve these traits.

Increasing grain yield is the most important goal in any breeding program. Since yield is a complex trait and involves several quantitative components with low inheritance, its direct evaluation is not usually sufficient and therefore it is suggested that its components be investigated instead. The objective of this study was grouping 60 inbred lines along with four check cultivars of wheat from the different phonological and agronomic traits, and selection of superior groups. Therefore, these lines and cultivars were examined in (8 × 8) square lattice design with two replications. In analysis of variance for the evaluated phonological and agronomic traits, significant differences were observed in the most traits that indicate high genetic diversity of these traits. Cluster analysis showed that selection of first cluster of lines for phonological traits and second cluster of lines for agronomic traits with selection for early flowering and high plant height, awn length and biomass could lead to selection of genotypes with high number of spike per plant, seed number per spike, 1000- grain weight and grain yield. As well as, because of more easily evaluation and more heritability, these traits can be recommended for indirect selection of grain yield and its components of wheat under rainfed conditions.

To determine relationships between seed oil and protein contents with some important agronomic traits, 364 soybean genotypes were evaluated using an augmented design in Seed and Plant Improvement Institute, Karaj, Iran, during 2004 growing season. Most agronomic traits had significant negative correlation with seed oil content, except number of seed.pod-1. However, most agronomic traits had highly significant positive correlation (p<0.01) with seed protein content, except seed oil content and number of seed.pod-1. Results of stepwise regression and path analyses showed that seed protein content and days to beginning of flowering had direct negative effect, and 100 grain weight had direct positive effect on grain oil content. Oil content and biomass also had direct negative effect, and 100 grain weight had direct positive effect on grain protein content. Canonical correlation analysis for seed yield and seed quality variables led to introduction of two pairs of variables. The first pairs was named "grain yield and number of grain.plant-1 " and "grain oil content" and the second pairs was named "grain yield and number of pod.plant-1 " and "grain protein content", respectively.

One of the approaches to agricultural sustainability is using diversity of plant species, including forage crops. A total of 64 accessions of forage grass genus: Agrostis, Bromus, Dactylis, Festuca and Phalaris were sown in a field experiment, and their agro-morphological traits were characterized according to standard descriptors. A high diversity was observed for most of the studied traits on the genus. F test was significant for most of the traits based on one-way ANOVA. Duncan mean comparison method was performed to grouping genus based on the recorded traits. Phalaris located in the highest rank for herbage summer yield followed by Bromus, Festuca and Dactylis in the next group and Agrostis and Poa located in the last group. Results showed forage grasses can be seemed as candidate to be used in agronomy systems due to the existence of high potential for forge yield in the studied materials.

Selection efficiency requires complete and accurate knowledge of genetic parameters such as heritability, phenotypic and genotypic variation coefficient, environmental variance, selection response, genetic gain, genetic and phenotypic variance, genetic and phenotypic correlation between traits that the breeder consciously chooses the appropriate selection method in breeding populations. In this study, some genetic parameters for yield and soybean agronomic and reproductive period characteristics under normal and stress conditions were estimated and drought tolerant genotypes are determined by the Ideal Genotype Selection Index (SIIG).

In 2013, in an experimental farm in Karaj, 50 soybean genotypes were cultivated in two normal and drought stress conditions in a randomized complete block design with three replications. Irrigation cycle was determined based on the amount of evaporation from the surface of Class A pan. During the growth period, the reproductive period characteristics and after the ripening agronomic traits were evaluated. After collecting experimental data, analysis of variance, mean, minimum, maximum values of traits, heritability, phenotypic and genotypic variation coefficient, environmental variance, selection response, genetic gain, genetic and phenotypic variance, genetic and phenotypic correlation, and SIIG index method was used for grouping genotypes based on drought tolerance.

Among the the reproductive period characteristics the highest and lowest genetic gain in normal conditions were 21.40 and 3.95% for day to the beginning of seed filling and the Reproductive relative duration respectively and in stress conditions were 21.9 and 7.3% for day to the beginning of seed filling and the Reproductive relative duration respectively.In normal conditions, the highest genetic gain was 0.52 for the number of pods per plant and the number of branches and the lowest genetic genetic gain was 0.14 for the number of nodes per stem. In stress conditions, the highest and lowest genetic gain were 104% and 0.14 for the number of pods per plant and the number of nodes per stem, respectively. In normal conditions, among the agronomic traits, the highest values of response to indirect selection of grain yield were 1.6 and 1.41 g, through 100-grain weight and number of seeds per plant respectively and in stress conditions, the highest values of response to indirect selection of grain yield were 1.04, 0.89 and 0.87, through The number of branches, number of seeds per plant and weight of 100 seeds were obtained respectively. Also, according to the Ideal Genotype Selection Index (SIIG), five genotypes were in the tolerant group, seven genotypes in the semi-tolerant group, 11 genotypes in the semi-susceptible group and 27 genotypes in the susceptible group. Roanak, Kabalovskaja and TMS genotypes were identified as the most drought tolerant and AGS 363, Hermen and Kuban as the most drought sensitive genotypes.

Based on the results, acceptable phenotypic and genotypic diversity in terms of agronomic traits was observed among the studied genotypes. Most of the genetic parameters measured were almost identical under both normal and stress conditions. The characteristics of the reproductive period had higher e selection response (direct and indirect), higher broadsense heretability and higher genetic gain than the agronomic characteristics. The highest indirect to direct selection efficiency for grain yield were obtained from number of seeds per plant and 100-seed weight under normal conditions,and The highest indirect to direct selection efficiencies were obtained from number of sub-branches, number of seeds per plant and 100-seed weight in stress conditions. Also in this study, based on the ideal genotype selection index (SIIG), Roanak, Kabalovskaja and TMS genotypes were identified as the most tolerant and AGS 363, Hermen and Kuban as the most sensitive genotypes.