فهرست مطالب محمود رضازاده باری

The study of genetic diversity is an important step in planning crop breeding programs. According to researchers, diversity of the population under selection ensures the desired results in breeding programs. In this regard, using the capacity of local populations to create new cultivars and achieve maximum diversity is very efficient. Therefore, the purpose of this study is to investigate the agro-morphological traits of pepper populations to identify the breeding potential of local populations for producing hybrid cultivars.

In the present study, 30 populations of Iranian peppers were planted in five replications in the research greenhouse of Department of Plant Production and Genetics of Urmia University, in order to study the genetic variability in terms of some agro-morphological traits. The experiment was conducted in a completely randomized design (CRD) in pot conditions in  2016-2017. In this study, variance analysis (ANOVA) and mean comparison of traits by Duncan's multiple range test, estimation of phenotypic correlation by Pearson method and principal component analysis on correlation coefficient and also cluster analysis by Ward method has done and realized. Also, the variance components, heritability (h2), phenotypic coefficient of variation (PCV), genotypic coefficient of variation (GCV), and environmental coefficient of variation (ECV) were calculated.

The results showed significant difference among the populations for all studied traits. The highest phenotypic coefficient of variation (PCV) (88.36) was observed for single fruit weight and also the highest genotypic coefficient of variation (GCV) (83.63) was observed for the same trait (single fruit weight). The pulp weight and fruit yield (0.950) had the highest significant positive correlation coefficient and the single fruit weight and fruit number (-0.558) had the highest significant negative correlation coefficient. According to the results of hierarchical cluster analysis, the studied populations were divided into five clusters based on the studied traits. The Tabriz population in the first cluster and the Gharah Bagh-Urmia population in the fourth cluster were superior in the fruit number trait.

In this study based on the results of mean comparisons Bash Ghala (from Urmia), Nakhchivan (from Urmia) and Keshtiban (from Urmia) populations were superior in terms of most of the studied traits. Also, Bash Ghala (from Urmia), Nakhchivan (from Urmia) and Keshtiban (from Urmia) populations were in the same cluster had higher fruit yield than other studied populations. Therefore, these populations can be used as one of the top parents in the intersection with other populations to create desirable genetic compounds.

Bioactive peptides are special protein components that have a significant effect on human body function. In this study, the effect of proteins and peptides resulting from the hydrolysis of amaranth proteins (total protein, albumin, and globulin) at levels 1 to 5% and different hydrolysis times (0.5, 1.5, 3, and 5 hours) on The properties of sourdough and the quality of bread were investigated. The results showed that the peptides obtained by hydrolysis of total amaranth protein in 3 hours had the greatest effect on the growth of Lactobacillus Plantarum (PTCC 1896) (11.40 Log CFU / mL) and Saccharomyces cerevisiae (PTCC 5052)  (8.32 Log CFU / mL) in vitro. These microbes are the main flora of sourdough and different amounts of peptides on their growth were statistically significant compared to the control sample. The titratable acidity and pH ‌ after 16 hours of fermentation at 30 ° C in the wet dough containing 5% peptide were 13.33 mL NaOH and 4.6, respectively, which was higher than other treatments. The highest amount of water activity, specific volume, titratable acidity, and the lowest enthalpy in bread was prepared from sourdough containing 3% peptide. Therefore, bread made from sourdough containing 3% peptides was selected as the best treatment to increase the quality of bread.

In the present study, the effect of incubation temperature (40 to 60 °C), fermentation time (48 to 72 hours), concentrations of permeate (5-10percent) and vinasse (0 to 15percent) as fermentation variable on the production and productivity of lactic acid were studied using a Box-Behnken design. The results showed that all four independent variables had a significant effect on lactic acid production (p 0.05). Optimization by the desirability function method showed that the maximum production of lactic acid by B. coagulance was at 41 °C, fermentation time of 63 hours, permeate and vinasse as fermentation medium was equal to 8.5 and 10percent (w/v). Thelactic acid production in these conditions was 10.23 g/L. Finally, an HPLC analysis was used to confirm the amount of lactic acid production.

Chitosan is a natural antimicrobial which is derived from non-toxic animal resources. This study investigated and compared the antimicrobial characteristics of chitosan which was extracted from shell of Artemia cyst in the lake of Urmia with the same commercial chitosan feature to that of crab shell from A.P.T firm in Vietnam. The experiment was carried by means of two fulded method to find the minimum inhibitory concentration (MIC) of commercial chitosan and Artemia chitosans and (4,2,1,0/5,0/25,0/125,0/062 mg/ml) (6/4,3/2,1/6,0/8,0/4,0/2,0/1 mg/ml) on Staphylococcus aureus, Escherichia coli, Salmonella typhimurium and Listeria monocytogenes. MIC of Artemia chitosan for those bacteria and MIC of commercial chitosan were determined 500 ppm and 800 ppm. In the next phase, each of those four bacterias was separately exposed to MIC Artemia chitosan and during 8 h of incubation at 37?C were artificially cultivated every 2 h and colonies appearing on the plates after 24 h of incubation were counted and the death time graph of the bacterias was drown to study their destruction process in the presence of MIC of Artemia chitosan. Experimental achievements showed that in this period of destruction speed in Staphylococcus aureus was more than others and the destruction speed of Salmonella typhimurium was the least. Also studying the achieved pictures by electronic microscope from the from two bacterias, gram-positive Staphylococcus aureus and gram-negative Escherichia coli which were exposed to MIC of Artemia chitosan (500 ppm) depicted that the speed of influence by Artemia chitosan on gram-positive bacteria is much more than gram-negative bacteria. Results of this study depicts great abilities of Artemia chitosan in destroying studied bacteria in comparis on with those of commercial one.