فصلنامه زیست شناسی تکوینی
سال پانزدهم شماره 1 (پیاپی 57، زمستان 1401)

Oilseed rape (Brassica napus L.) is one of the important economic plants cultivated in Iran. Boron (B) and iron (Fe) as micronutrients and calcium (Ca) as a macronutrient are essential for higher plants and inadequate supply of these nutrients causes nutritional disorders. Boron deficiency (–B) is a widespread nutritional deficiency in oilseed rape throughout the world and this species has been known as a susceptible species to B deficiency. In this study, the responses of six genotypes of oilseed rape plants to B deficiency were investigated in the hydroponic medium. In addition, the interaction between B deficiency and deficiency of Fe (–Fe–B) and Ca (–B–Ca) were examined in hydroponically grown oilseed rape (cv. Hayola) plants. Results showed that B deficiency decreased shoot and root biomass and root length, decreased B content, chlorophyll fluorescence and gas exchange parameters. 'Opera' was the most susceptible and 'Okapi' the most tolerant genotype to B deficiency. The simultaneous deficiency of B and Fe (–Fe–B), B and Ca (–B–Ca) strongly reduced shoot and root growth, enhanced the release of protons leading to acidification of the rhizosphere and caused higher K+ leakage from the roots and reduction of B content both in the roots and leaves. Our results showed a considerable genotypic difference in oilseed rape plants in response to B deficiency. Our data further demonstrated the intensifying effect of inadequate supply of Fe and Ca on B deficiency in oilseed rape plants

Pseudomonas aeruginosa is a gram-negative bacillus and an opportunistic pathogen. This bacterium is the third most common cause of nosocomial infections. Exoenzymes T, S, U, Y are secreted by the type III secretion system, which is one of the important pathogenic factors of this bacterium, and exotoxin A is secreted by the type II secretion system. In this study, the frequency of exoA and exoT genes in clinical strains of Pseudomonas aeruginosa and the antibiotic resistance of the strains were investigated. 29 strains of P. aeruginosa bacteria were identified from patients admitted to Razi Hospital in Rasht, using common microbiology methods and were examined along with the standard strain of ATCC27853. The resistance of these strains to 6 types of antibiotics was determined using disk diffusion method. Then DNA extraction and PCR was performed to determine the frequency of exoA and exoT genes. In this research, the highest rate of antibiotic resistance was observed for Imipenem(86.75). The results obtained from PCR showed a frequency of 37.93%for exoA and 68.96% for exoT.

The genus L. Crataegus belongs Rosaceae family. It has economic importance due to its widespread use in traditional medicine and landscaping. This genus has a lot of complexities from a taxonomic point of view and so far many plans have been presented to classify the species of this genus into sections or subgenera. In this study, morphological traits along with ribosomal DNA (ITS) region sequences were used to study the progeny relationships as well as to determine the species boundary in this genus. In morphological studies, 43 traits (14 quantitative traits and 29 qualitative traits) of vegetative and reproductive organs of 14 species of this genus were studied and the obtained data were statistically analyzed by specialized software such as PAST and SPSS. . In phylogenetic studies, the nuclear genomes of 14 species were extracted by DNA Extraction Kit (MBST) and their DNA sequences along with ITS sequences of 19 non-Iranian species of this genus were extracted from NCBI site and then analyzed by PAUP and Figtree softwares were analyzed based on Maximum Parsimony (MP) method. Although the classification of species based on The maximum Parsimony method was consistent with the monograph presented by Christensen, but these results did not confirm the proposed schemes for classifying species in the flora of Iran.

Cotton (Gossypium spp.) included 5 tetraploid (2n=4x=52) and more than 45 diploid (2n=2x=26) species. Tetraploid species of cotton are formed through hybridization between an A- genome and a D- genome. Genome mapping analyses showed that there is high level of similarity between diploid A- and D- genomes with tetraploid At- and Dt- genomes. G. stocksii and G.longicalyx belong to D genome, which is an important wild bio-source for the cotton breeding and genetic research. Present study was conducted to study and compare the complete chloroplast sequence of two diploid species of cotton (G.stocksii and G.longicalyx) compared with two tetraploid species (G.hirsutum and G.barbadense), analyses of their genome structure, gene content and organization, repeated sequences and codon usage has been carried out. G.longicalyx chloroplast (cp) genome is 160,248 bp in length which longer than G.stocksii and shorter than two tetraploid species. G.stocksii chloroplast (cp) genome is 159,039 bp in length which shorter than G.longicalyx and shorter than two tetraploid species. In both species single copy regions of cp genome is separated by the two inverted repeats. The plastidic genomes of G.stocksii and G.longicalyx comprised of 79 protein coding genes, 4 ribosomal RNA genes and 30 transfer RNA genes, 113 single genes in total and 20 duplicated genes in inverted repeats. In both diploid species 5 ycf genes with unknown function have been identified. These genes considered essential for plants and are highly conserved in plant taxa.

This experiment was performed to evaluate the use of extracts of Echinacea, Thyme and Peppermint on performance, carcass characteristics, blood factors and immune system of Japanese quail. One-day Japanese quail chicks were divided into 5 treatment groups based on a completely randomized design. Each treatment had 4 replications and each replication included 10 chickens. Experimental treatments are: 1) control (basic diet-without additives), 2) basic diet + 0.2% of Echinacea extract, 3) basic diet + 0.2% of thyme extract, 4) basic diet + 0.2% of peppermint extract and 5) Basal diet + 0.2% Echinacea extract + 0.2% Thyme extract + 0.2% Peppermint extract. Weight gain, live weight and conversion coefficient improved significantly by adding medicinal plant extracts to the diet (P<0.05). Carcass percentage in treatments containing Echinacea, peppermint as well as a mixture of Echinacea, thyme and peppermint had a significant increase with the control (P<0.05). There was a significant decrease in Abdominal fat in all experimental treatments with control (P<0.05). With the addition of medicinal plant extracts, the concentrations of total protein, uric acid and cholesterol were significantly reduced (P<0.05). Medicinal plant extracts had no significant effect on the concentration of liver enzymes and immune system of quails (P>0.05). In general, the results showed that the application of a mixture of herbal extracts of Echinacea, Thyme and Peppermint in the diet of Japanese quail can have a higher efficiency on growth performance than the separate application of each of them.

Extracellular Polysaccharides or Extracellular Polymeric Substances, EPS are polyester compounds that are produce in some cyanobacterial genera. In this study, physiological characteristics and extracellular polysaccharides have been investigated and compared in three different cyanobacteria; a heterocystic bundled, a nonheterocystic bundled and single cell strain. The results of growth rates and growth curves of these three samples indicate that cyanobacterium unicellular Synechococcus sp. Compared to heterocystic bundled; Nostoc sp. and nonheterocystic bundled Phormidium sp. is growing more. Meanwhile, the polysaccharide measurements of these three samples show that the production of the polysaccharides of all three samples at the end of the growth phase reaches the maximum and that the strain of Phormidium sp. has the ability to produce the highest amount of polysaccharides, especially extracellular, whereas the nitrogenase activity of these strains was also consistent with their growth, so that the strain of Synechococcus sp. has the most nitrogenase activity and Nostoc sp. has a second rank in this regard, with a minor difference. In this way it is concluded that the strain of Phormidium sp. is a prime example that has the ability to produce polysaccharides, especially extracellular polymers, to a large extent scale, and can compete in different sectors with synthetic polymers such as xanthan.

The amount of insulin-like growth factor (IGF) is regulated by various stimuli such as hormones, growth factors and nutritional conditions. In the present study, the effect of different levels of phytase enzymes on the expression of IGF-1 gene in the liver tissue of broiler chickens was investigated. The experiment was conducted with 7 treatments, 5 repetitions and 25 chicken pieces in each repetition. Experimental diets including the control diet, whose required phosphorus was provided by dicalcium phosphate, and the diets containing different commercial microbial phytase enzymes based on corn and soy were investigated. In order to investigate the expression of IGF-1 gene, first, total RNA was extracted from liver tissue and after making cDNA, the gene expression level was measured using real time PCR technique. The results of examining IGF-I gene expression in different levels of phytases showed a significant difference between the treatments. The expression of IGF-I gene in treatments 1 and 2 including phytase hostazim and phyzyme showed the lowest expression level and treatment 6 with phytases hostazim and ranozyme 100% showed the highest expression level. Increasing the amount of phytases increases the expression of IGF1-mRNA in the liver and can subsequently affect the performance of growth traits.