فهرست مطالب seyed hasan marashi

Considering the limited production of edible oil in the country, selectivity of the genotypes of valuable oilseeds like sesame is important. A randomized complete block design with three replications was conducted in the research farm of the Ferdowsi University of Mashhad in 2021, to investigate 20 sesame genotypes' yield, and yield components and determine the most important traits affecting the yield. The results showed that Afghan1, Afghan3, and Afghan5 genotypes had the highest number of capsules plant-1 , 1000-seed weight, biological yield, and seed yield. Also, the correlation analysis between the traits showed that seed yield had a positive and significant correlation with the number of capsules per plant (r=0.58**), and 1000-seed weight (r=0.42**), respectively. Based on the principal component analysis, in total two components explained 83.1% of the variation in data. The first component explained 57.7%, and the second component showed 15.2% of the most changes in variation between genotypes. Then, these two components used to determine the distribution and distinguish the best genotypes in the results. As a result of cluster analysis, genotypes were categorized into three groups based on yield and yield components. The genotypes of the third group (Afghan1, Afghan3, Afghan4, Afghan5, and Afghan7) had a higher average in the investigated traits than other groups. These results indicate that the most effective traits in sesame yield are the number of capsules per plant and the 1000-seed weight. Since high yield is one of the important breeding goals in sesame; therefore, genotypes with these characteristics can be introduced as superior genotypes.

Cellulose which is extremely produced by plants, can be used for biofuel production but this function needs chemical or enzymatic digestion. Cellulose hydrolysis of plant wastes for ethanol production requires a mixture of three enzyme groups, including endoglucanases, exoglucanases, and beta-glucosidases. The cellobiohydrolase enzyme (Cel6B) from Thermobifidia fusca has been used for cellulase activity extensively. This research aimed to express recombinant Cel6B enzyme in Pichia pastoris. For this purpose, cel6B gene in control of AOX1 promoter (methanol inducible) was introduced into Pichia pastoris. Amplification of cel6B gene was performed by PCR technique and then introduced into the Phil-S1 yeast vector. The recombinant construct contained the cel6B gene sequence and PHO1 signal sequence as secretion signal was transferred into Pichia pastoris GS115 strain. The transformed yeast cells expressed the recombinant Cel6B to yield 2.104 U (µmol/min)/ml of culture medium. Purified recombinant enzyme showed the best activity at 60 °C and pH 4.5 and this was agreed with optimum conditions for recombinant Cel6B enzymes which were produced in other systems. The purity of the enzyme was examined by SDS–PAGE technique, and a single band with a molecular weight about 59.6 kDa was observed. As cel6B gene sequence was not optimized for expression in the Pichia pastoris yeast, this could be one of the reasons for low level activity of recombinant Cel6B enzyme. This thermostable enzyme can be used for cellulolytic digestion of biomaterials in biofuel production research and other uses.

Chickpea (Cicer arietinum) is very sensitive in competition with weeds and suffers from a decrease in yield and product quality. Therefore, it is useful to produce plants resistant to general herbicides such as glyphosate. In this research, Agrobacterium tumefaciens strain LBA4404 was used. This bacterium contains plasmid pBI121 and mutated epsps gene of Escherichia coli to create resistance to glyphosate herbicide. In this plasmid nptII gene is placed under 35S promoter as a selective gene. In order to transfer the gene, embryonic axes of chickpea varieties (Samin and Bivanij) were used. Chickpea embryonic axes were placed on B5 co-culture medium after co-cultivation with bacterial suspension for 3 days and then transferred to MS culture medium with appropriate concentration of BAP, Kin and NAA hormones for regeneration. Finally, after successive selections using kanamycin antibiotic, rooting and establishment of T0 plants were done in hydroponic environment. Then, PCR amplified epsps and nptII genes in 15 plants and their transgenecity was confirmed. Non-contamination of DNA in putative transgenic plants was confirmed by using the primers of the bacterial ITS regions. Also the expression of the target gene verified using RT-PCR test and the transgenic percentage was 0.75% in this study.

Mexican lime is one of the most important and economic fruit crops in the southern regions of Iran. This crop is susceptible to Citrus Tristeza Virus (CTV) and Witches Broom Disease of Lime (WBDL). Therefore, optimization of regeneration and transformation system for this plant is necessary for its improvement. In this project, the effect of different factors such as internode and epicotyl explants; two different regeneration media containing different concentrations of BAP and NAA, different Agrobacterium strains: “LBA4404” and “EHA105”, each harboring a binary vector pBI were studied in a factorial experiment. The results showed that the etiolated epicotyl was the best explants for regeneration and callus production. There was no significant difference between two regeneration media. Furthermore, EHA105 was the best Agrobacterium strain for this purpose. Polymerase Chain Reaction (PCR) using gus-specific primers has been carried out on DNA extracted from all regenerated plants. Twenty-one shoots were carrying this gene but only 8 shoots out of these 21 showed the expression of this gene. Furthermore, the lack of Agrobacterium-related infections has been confirmed using virG-specific markers.