فهرست مطالب مشترک دکتر سید حمیدرضا هاشمی پطرودی و دکتر غلامعلی رنجبر

Sesame is one of the oldest products known to man to date. Sesame was a valuable crop in the ancient world due to its drought resistance, ease of oil extraction from seeds and oil stability. Iran is one of the arid and semi-arid regions of the world in terms of climate. In these areas, low and scattered rainfall and high evaporation usually cause the accumulation of salts in the surface layer of the soil. Therefore, the salinity of soil and irrigation water causes significant morphological, physiological and chemical changes. Excess salt, that is, more than plants need limits crop growth and production and can lead to plant death.

In this experiment, 20 sesame genotypes were grown in greenhouses. The experiment was performed as a factorial in a completely randomized design with three replications. 75 mM sodium chloride was dissolved per liter of water and the pots were irrigated with saltwater. Percent morphological traits loss index (PML) was calculated.

According to the results of analysis of variance and comparison of the mean interaction of cultivar × stress in all studied traits were significant. American and Yellow- White cultivars with 17927 and 14.07 g, respectively, the highest and 714 and Dezful with 2.43 and 2.07 g, respectively, the lowest yield under normal conditions, and Oltan and American cultivars, respectively, with an average of 963 8.8 and 7.34 g had the highest and Darab 1 and Dezful had the lowest yield under stress conditions with 0.92 and 0.71 g, respectively. In this study, clustering method was used to group and separate useful (high yield) and susceptible (low yield) genotypes based on different traits. The results showed that the studied genotypes were grouped based on morphological traits and yield reduction percentage index using standard data. The studied genotypes were divided into 3 groups. In the first group, Oltan, American, Chinese, Dashtestan 2, 369 and 418 genotypes with the highest yield among the genotypes were studied. The second group included Darab 1, 730 and Dezful genotypes and the third group included other genotypes. In the first group, it is desirable to distinguish high-yield genotypes with desirable traits and the lowest percentage of yield reduction under salinity stress conditions from other genotypes.

The results of this experiment showed that there is a favorable variation among the study population, especially a significant difference was observed between the performance of genotypes in both normal environmental conditions and salinity stress. Correlation analysis of traits showed that under normal conditions, number of seeds per plant, number of capsules per plant and 100-seed weight, and under salinity stress, number of seeds per plant, number of capsules per plant and single plant weight had the highest correlation with yield. In this experiment, the best salinity tolerant lines were Oltan, American, Chinese, Dashtestan 2, 369 and 418 genotypes. It is noteworthy that these genotypes had a more stable performance than others in both conditions, so they have stress tolerance genes and can be considered in future studies. Also Darab 1, 730 and Dezful genotypes were the most sensitive genotypes to salinity stress in this experiment.

Dehydrins (DNHs) belong to group II of LEA (Late Embryogenesis Abundant) protein family which are expressed in late embryogenesis and accumulate in vegetative tissues in response to multiple abiotic stresses such as salt, drought and cold stress These proteins could be classified to five subgroups (YnSKn, Kn, SKn, KnS, and YnKn) based on the sequence and number of K, S, and Y segments. In this study, 5 genes encoding dehydrin protein (DHN) were identified in Aeluropus littoralis, genome as a halophyte grass, belonging to the Poaceae family and physicochemical characteristics, cell localization, conserved motifs and gene structure were determined and evolutionary relationships among different species were considered. AlDHN proteins were classified in the YnSKn subgroup based on highly conserved domains. The expression pattern of AlDHN.5 gene as a homologue of RAB18 (AT5G66400) gene was examined in both leaf and root tissues under salinity, drought, cold stresses and abscisic acid treatment. Analysis of the expression pattern of this gene in both leaf and root tissues showed that this gene is more expressed in leaf tissue compared to root under drought, cold stresses and ABA treatment. Current study lays the foundation for further studies into the regulation of their expression under various environmental conditions.

Marker-assisted selection (MAS), a selective method which is not influenced by environmental factors. The success of MAS-based breeding programs depends on the selection and validation of the markers used. In this study, to validate the gene(s) associated with salinity stress And evaluation of allelic diversity of these markers in mutant rice lines, Band pattern of 18 SSR markers on a leaf sample of 14 mutant lines (M9) of rice, along with 2 susceptible controls (IR29 And Sepidrood) and 2 tolerant controls (Nonabokra and Dylmani) in 1398 in Genetics & Agricultural Biotechnology Institute of Tabarestan (GABIT). 11 primers were selected based on band pattern analysis in susceptible / tolerant cultivars. The molecular analysis results showed that OsMAPK4, OsCML11 and OsCPK17 had highest polymorphic information content (PIC). OsMAPK4 and OsCML11 had highest marker index (MI) at a rate of 0.23. The lowest PIC (0.05) and MI (0. 11) was accounted for OsCAX(D). Cluster analysis of molecular data, divided rice genotypes into three distinct groups. However, analysis of Biplot classified the genotypes into four different groups. In this study, 3 genes OsCML11, OsMAPK4 and OsCPK17 were identified on chromosomes 1, 6 and 7 respectively, as the most efficient primers in identifying the genetic diversity between the rice genotypes, Considering that these primers have a very high linkage with salinity resistance genes, can be predicted that 3 lines G1 (M9-P1-7-2-1), G8 (M9-P3-21-1-1) and G9 (M9-P6 -7-1-1) have high tolerance to salinity stress.