فصلنامه ژنتیک نوین
سال پانزدهم شماره 3 (پیاپی 62، پاییز 1399)

In recent years, increase in human-induced habitat disturbances and illegal hunting have led to reduction and isolation of the remaining populations of the brown bear. Despite its ecological importance on the health of natural ecosystems, there is a data scarcity on the genetic diversity and kinship relationships between individuals in the remaining populations. Advances in the DNA extraction from non-invasive samples has facilitated genetic studies on vulnerable species. In the present study, we used non-invasive sampling methods to assess genetic diversity indices, the probability of genetic identity among individuals, and the number of unique genotypes in the samples in order to estimate the minimum number of brown bears in the Parvar protected area. A total of 10 microsatellites were amplified using the extracted DNA from non-invasive samples. The overall observed heterozygosity, expected heterozygosity, and polymorphic information content were estimated 0.51, 0.57, and 0.5 respectively. The probability of identity indices (i.e. PID sib and PID unbiased) were 0.078 and 0.0032 respectively. Also, a total of 19 unique genotypes were identified. Our results showed that despite the low quality of non-invasive extracted DNAs, the amplified microsatellites had statistically effectiveness in identifying samples, assessing probability of genetic identity, and estimating minimum population size. The adopted approach in the present study can be used as a guideline for estimating population size and evaluating kinship relationships between individuals, especially for threatened carnivores, using non-invasive sampling approach.

Salinity stress is one of the most important abiotic stresses affecting the yield of oilseed rape. To study the physiological and biochemical changes, and expression BnaCDPK6, BnaCDPK 10 genes in rapeseed (Brassica napus L.). Two tolerant cultivars (Slm046 and Zarfam) and two susceptible cultivars (Okapi and Sarigol) were planted in a growth chamber and were irrigated by 100 and 200 mM NaCl and normal water. Studied parameters include relative water content, malondialdehyde, the enzyme activity of antioxidant enzymes (Superoxide dismutase and Catalase) and the expression of calcium-dependent protein kinase 6 and 10 coding genes (BnaCDPK6, 10).  The result indicated the relative water content and malondialdehyde with a high level of salt (200 mM NaCl) decreased and increased under stress respectively. The antioxidant enzymes Superoxide dismutase and Catalase content and BnaCDPK6 and BnaCDPK10 expression increased by high severity salinity stress that tolerant cultivars showing more increase. These results indicated that increasing the reactive oxygen species due to salt stress plays an important role in damaging cell membrane in canola, and the plant increases its protective mechanisms against the production of reactive oxygen species by increasing the activity of antioxidant enzymes and an increase in the expression of calcium-dependent protein kinase genes expression.

Iran is the origin and rise of the Arabian horse. Each year, the breed originality of the new born horses will be confirmed and registered by the World Arabian Horse Organization (WAHO) through the DNA test. The aim of this study was to unbiased estimation of phenotypic and genetic correlations of the conformation traits with the racing performance traits of the Iranian Arab horse through designing the appropriate statistical models. In a randomized sampling, six important traits were recorded, including withers height, body length, hind cannon circumference, fore cannon circumference, thorax girth and chest depth. The best racing time in distance of 1250 meters, the best racing time in distance of 1750 meters, and the best place in distance of 1250 meters were recorded by reviewing the horse racing films. To estimate the genetic correlations, the multi-trait animal model and derivative free-restricted maximum likelihood and DFREML software were used. The highest and the lowest genetic correlations were estimated for the thorax girth with the best place in distance of 1250 meters (-0.70±0.08) and the fore cannon circumference with the best racing time in distance of 1250 meters (0.06±0.00), respectively. Generally, high genetic correlation was estimated for the body conformation and performance traits. Therefore, at the young age, conformation traits can be used for the selection of the reproductive and appropriated horses for the racing and then reduced the generation interval and increased the genetic progress.

The chickpea yield (Cicer arietinum L.) is reduced by cold stress in autumn and spring cultivation. In this experiment, biochemical and molecular responses in the nodules of two chickpea genotypes, cold tolerant (Sel96th11439) and cold sensitive (ILC533), incubated with Mesorhizobium ciceri during cold stress treatment (4˚C) were studied in a factorial experiment completely randomized design with three replications. Comparing to control conditions, the rate of cellular damage index (hydrogen peroxide) in tolerant and sensitive genotypes nodules showed significant decrease (by 53%) and increase (by 32%) on the sixth day of cold stress, respectively. Under cold stress, in the tolerant genotype nodules, increased expression of CaADC, CaODC, CaSPDS and CaSAMDC genes resulted in induction of biosynthesis pathway and accumulation of PAs. Results showed that CaADC had a more efficient role in activation of this biochemical pathway compared to CaODC gene. The highest increase in relative expression of studied genes was observed on the sixth day of cold stress, which corresponded to a decrease in cell damage index (H2O2) and an improvement in the degree of tolerance to cold stress. These results indicated that in chickpea nodules, physiological-molecular mechanisms determine the degree of tolerance to cold stress. In general, the use of efficient rhizobium strains can be useful in developing breeding approaches aimed at improving tolerance to cold stress due to the symbiosis of chickpea-rhizobium.

Barley net blotch caused by the fungus Pyrenophora teres is a major barley disease in Iran. Identification of genomic regions associated with net blotch resistance could accelerate the process of producing new resistance cultivars. For this study, a population of 142 two-row spring barley cultivars was used for association mapping analysis using 407 SSR and AFLP markers. Phenotypic data were also obtained from disease evaluation in two seedlings and adult plant stages. Seedling (with an isolate of spot form net blotch) and adult plant stage evaluation respectively, under control conditions of Mashhad Agricultural Research Station (Toroq), and the field of Araqi Mahale Agricultural Research Station (Gorgan) during 2016-17 and 2017-18 cropping seasons. Results showed that respectively 83 and 80% of cultivars were semi-susceptible to susceptible in seedling and adult plant stage. Population structure analysis subdivided the studied cultivars into two subpopulations (K=2). The results of association mapping analysis for seedling and adult plant stages revealed that six and 13 QTLs associated with disease resistance were identified, respectively, that accounting for 2.9 (QRpts6H) -18% (QRpta4H) of the genetic variation. Four markers––E38M50-119, E38M50-355, E38M50-390, E35M54-163––were common in both growth stages. Detection of these markers could help in more detail understanding on the genetic architecture of resistance to net blotch and development of diagnostic molecular markers and be a prelude for more detail understanding of research into the candidate regions identified in the barley genome.

Considering the importance of wheat, it is very important to identify the expressed proteins in the different stages of growth for improvements and enhancing the efficiency of production. The stage between germination and tillering is called leaf development. In the leaf development stage, the seed embryo has three primate cells of leaf that they start to divide after the growth of meristem of stem’s peak starts to germinate and it contributes to emergence of a new leaf. The sampling was happened in three stages: one leaf, two leaves, and three leaves. The proteins were extracted according to TCA-acetone method from the wheat leaf samples. They were separated by two-dimensional electrophoresis later. 360 repeatable protein spots were identified with by analyzing the gels extracted from two-dimensional electrophoresis. From this number, 31 protein spots indicated significant changes in 5% level in the different stages of leaf development. 55% of identified proteins indicated the decrease of expression and 19% shows the increase in expression and 26% of identified proteins did not have regular and significant changes. Finally, each protein spot with meaningful changes, regarding the molecule weight, isoelectric point, the shape of spot and with search in related literature and uniprot website, was identified possibly. The results showed that a vast range of metabolic activities including photosynthesis, breathing, proteins, biosynthesis, proteins transformation, assembly and packing of proteins, carbohydrates, biosynthesis, message translation system, detoxification, and genetic fundamental procedures (replication, duplication and translation) were changed during the different stages of leaf development. Most proteins showed the decrease of expression, were from chloroplast enzymes and mitochondrial enzymes. And most proteins that had increasing change procedure were from healing and protective proteins.

The aim of this study was to investigate the nucleotide diversity and the phylogenetic analysis of pancreatic ribonuclease gene in two different species, Baluchi and Urial sheep. Baluchi sheep blood samples were collected from Abbas Abad Animal Breeding Center, Mashhad and Urial sheep blood samples were collected from Khorasan Razavi Environmental Department. The 4347 bp pancreatic ribonuclease gene was amplified and sequenced using seven primer pairs that were designed to overlap each other. Comparison of 4347 bp pancreatic ribonuclease gene sequences obtained from both Baluchi and Urial sheep strains showed 10 nucleotide differences with 99.78% similarity. Also results of comparison of pancreatic ribonuclease gene from the sheep reference genome (Accession number of XM_004010384) with Urial sheep and Baluchi showed differences in 18 nucleotides with 99.61% similarity and 10 nucleotides with 99.78% similarity, respectively. The results of the present study confirmed that although the pancreatic ribonuclease coding enzyme sequences of the two species, Baluchi and Urial and the reference gene sequences from the NCBI database are completely similar, but the upstream and downstream nucleotide sequences of this gene have 10 nucleotide differences with each other. There are 18 nucleotide differences with the sheep reference sequence. Results of genetic interval matrix and phylogenetic tree sequences of Baluchi sheep and Urial sheep obtained in this study with other gene sequences registered from pancreatic ribonuclease in the NCBI database, it confirmed that both Baluchi and Urial sheep species with the sheep reference sequence for pancreatic ribonuclease gene sequence were assigned to a goat species belonged to the same clade.

Aegilops genus is the main genetic source of variation for wheat breeders due to its breeding potential such as tolerance to both abiotic and biotic stresses. The main objective of this study were to evaluate the genetic diversity in 91 Aegilops accessions belonging to Ae. cylindrica and Ae. crassa using microsatellite (SSR) markers. A total of 49 fragments were amplified using 25 tested primers in which 48 products were polymorphic. The average values of polymorphic information content (PIC) and gene diversity (H), resolving power (Rp) and marker index (MI) were 0.26, 0.34, 1.29 and 0.51, respectively. The results of molecular variance analysis (AMOVA) showed the highest portion of genetic variance referred to inter-species compared to intra-species. Based on genetic variation parameters, the highest values of variation parameters were recorded in Ae. crassa than Ae. cylindrica accessions. Cluster analysis based on Jaccard’s coefficients and neighbor-joining algorithm grouped all investigated accessions into two main clusters, so that all accessions were clearly separated from each other. The result of principal coordinate analysis (PCoA) revealed that the first two components accounted for 64.98% of the total molecular variation. The PCoA-based biplot grouped all investigated accessions into two main groups. The result of population structure showed that all investigated accessions were recognized into five subpopulations, and FST index among them varied between 0.52 and 0.76 with an average of 0.76. In conclusion, these results indicated high genetic variation in Aegilops genus collection and could be used in Wheat improvement programs and other genetic studies like QTL and association mapping are recommended.