Background: Diabetic retinopathy (DR) is a severe complication of diabetes and the leading cause of blindness among working adults worldwide. Chronic extra cellular hyperglycemia in diabetes stimulates reaction oxygen species (ROS) production and increase oxidative stress. Glutathion Stransferases (GSTs) enzymes have been shown to protect human from reactive oxygen compounds damage. The aim of the present study was to investigate whether the genetic polymorphism of GSTP1 is associated with DR.Materials and Methods: This case–control study, included 70 patients with DR and 70 healthy volunteers. Genomic DNA was extracted from peripheral blood leukocytes. Genotypes were determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Statistical analysis was performed using the MedCalc program for Windows version 12.Results: The prevalence of genotype frequencies of the GSTP1 Ile/Ile and Ile/Val were 71.42% and 28.57% respectively, in DR subject, whiles in healthy volunteers were 78.58% and 21.42%, respectively. Statistical analysis has not emerged significant difference from the comparison of either genotype (Ρ>0.05).Conclusion: There was no evidence that GSTP1 variants were associated with DR in studied population. Further research is required to clarify role of GSTP1 in DR.

In order to determine of genetic variation in germplasm of 120 watermelon accessions, a field trial conducted at agricultural and natural resource research center of khorasan. These Accessions with four commercial cultivars as control were planted in agnomental design with six replications. 15 quantitative morphological traitS were measured and some statistical parameter and analysis include of Mean, Coefficient variance, cluster analysis, correlation regression coefficients were determine for this traits. yield, sugar percent, time between flowering and ripping, fruit length, fruit width, fruit mass to fruit weight ratio, fruit skill to fruit weight ratio, seed weight to fruit weight ratio, 100 seed weight, seed length, seed diameter, seed width were the most useful traits for identifying of genotypes from each other. A one side analysis of variance was performed for different regions genetic diversity.Detection, which indicated a significant difference between regions for all traits except fruit pH and fruit skin thickness Cluster analysis divided genotypes into eight groups based on quantitative data. Correlation analysis between traits showed a significant relation between yield and all traits except fruit pH, time to flowering and seed fruit length.

Tobacco (Nicotiana tabaccum) is one of the valuable agricultural and industrial crops that there is little information about its variation. For studying genetic variation on the basis of morphological characteristics, a number of 100 exotic and endemic oriental tobacco genotypes were obtained from the germplasm collection of the Urmia Tobacco Research Center, Urmia, Iran, using simple lattice design with 2 replications. Eight traits include: stem height and diameter, leaf number per plot, leaf length and width, fresh and dry leaf weight and day to 50% flowering were examined. Principal component analysis could reduce the studied morphological traits to 5 components having 96% accumulative variance. In the first component, all traits (except stem height) showed positive significant correlations with. Cluster analysis using UPGMA method distinguished genotypes in 4 different groups. Maximum distance was between groups 1 and 4. Mean comparison revealed that genotypes (Trimph and Ohdaruma) belong to group 4 had the maximum value of most examined traits, therefore, they could be utilized as parents of crosses in breeding programs.

Annual species of Medicago are important pasture legumes in western parts of Iran. Due to limited karyotypic reports on annual Medicago species, the present study was conducted on accessions available in gene bank of Iran. Total length of chromosomes, size of long and short arms and their ratio were the basis for karyological measurement. Karyotypic studies showed that M. radiata 29, M. radiata 588, M. minima 316, M. polymorpha 1123, M. orbicularis 449, M. litiralis 1038, M. trancatulla 1146 and M. polymorpha 612, carried 2n=2x=16 chromosomes and Medicago rigidula 2n=2x=14 chromosomes. Among species with 2n=2x=14, M. rigidula 1126 had the highest total chromosomal length and  M. rigidula 454 the least total length. Species M. littoralis 1038 and M. minima 316 both with 2n=2x=16, had the highest and the lowest total chromosomal length, respectively. Total chromosome length and mean of chromosome length in most of exotic species were more than those of landraces. Species and varieties with larger karyotype had larger seed size. B chromosome found only in the M. littoralis and M. polymorpha species. Satellite chromosome observed in varieties 606, 1126 and 1199 of M. rigidula, 1123 and 612 of M. polymorpha and M. radiata 588. Resultes of cluster analysis revealed that varieties and species with similar karyotypice size and mean chromosomal length, did not show any significant differences, hence they were located in one group. Factor analysis revealed that chromosomes number 5, 6, 7 (2x=14) and 7, 5, 2 (2x=16) showed maximum structural change among accessions. Karyotype symmetry were determined by using coefficient of variation (CV) and total form percentage (%TF). Resultes of CV showed that the most of variation between chromosomes belongs to M. polymorpha 612 and the least of variation between chromosomes belongs to M. rigidula 1128. According to TF, M. minima 316 had the most karyotype symmetry and M. rigidula 1126 showed the least karyotype symmetry.

genetic variation is necessary factor for continued breeding and increasing genetic gain from selection in crop plants. To evaluate genetic variation and genetic gain from selection in bread wheat, 45 genotypes consisting of 9 cultivars and their 36 crosses were grown in a randomized complete block design with three replications in research farm of Isfahan University of Technology. The phenotypic and genotypic coefficients of variation for grain yield (24.6% and 21.7%, respectively), grain number per main spike (19.6% and 19%), grain weight per spike (19.6% and 19.6%) and biological yield (18.6% and 16.5%) indicated that there is a great degree of variation for these traits in this study. The highest narrow sense heritabilities were belonged to grain number per spike (79%), spike length (62%), 1000 grains weight (58%) and spikeletes per spike (57%) . Due to magnitude of heritability of grain yield (18%), its genetic gain (9.12%) was relatively low compared with other traits. The genetic gain for grain number per spike (32.3%), 1000 grain weight (14.3%), and grain weight per spike (12.9%) was larger than other evaluated traits. In general, selection of superior genotypes based on grain number per spike and thousand grains weight could improve grain yield in breeding programs of wheat.

In this study, the genetic variation in Zandi sheep was investigated using 15 microsatellite markers. Genomic DNA was extracted from 120 Blood samples, using modified salting-out method. All of fifteen loci were amplified successfully and all tested loci were all polymorphic. The Tests of genotype frequencies for deviation from the Hardy-Weinberg equilibrium (HWE) were performed at each locus and revealed significant departure from HWE (P<0.001) due to heterozygote excess. Parameters of variability such as effective number of alleles and gene diversities (Heterozygosity) corroborated the high level of variation frequently displayed by microsatellite markers. Furthermore, other criteria of genetic variation including PIC values and Shanon information index had calculated in this study. The mean of polymorphism information content of the Zandi sheep population was equal to 0.808 and indicate high level of polymorphism. Also the Shannon's information index of the Zandi sheep population was high (1.92 ± 0.09). Based on results of this research, high level of genetic diversity was observed in Zandi breed. This research also was shown that microsatellite markers is a useful tool for evaluation of genetic variation among of domesticated animals.

In order to identify polymorphic microsatellite markers and evaluae genetic variation within Baluchi sheep population, nineteen microsatellite loci were studied. Whole Blood samples were collected from 156 sheep at north eastern animal breeding station of Iran (Abbasabad-Mashhad). DNA was extracted by salting-out procedure with some modifications. Polymerase chain reactions were successfully done except for UNC5C locus. PCR products were electrophoresed on 8% denaturing polyacrylamide gels stained according to rapid silver staining procedure. The genotype and allelic frequencies were calculated by direct counting and used for estimating of different polymorphism and genetic variation criteria. This population wasn't at Hardy-Weinberg equilibrium except for OarAE101 locus (P<0.005). Heterozygosity (gene variation) ranged from 0.1 to 0.93. BULGE5E and BM1329 loci were monomorphic. In conclusion, this investigation showed high polymorphism at the studied loci, so they could be used in future studies.

To investigate genetic variation between lucern (M Sativa) germplasm, 25 cultivars of the species were studied in a randomized coplete block design in three replications in 1996. Fourteen characters were recorded on the plants of each plot. Regarding analysis of variance, significant differences were found between the cultivars at 5% and 1% levels of probability. In other words, the cultivars were different for the studied characters except for the lenght of main stem of first cut, the lateral stem length of first cut, dry matter yield of first cut, the main stem diameter, growth type and the main stem length of second cut. Regarding dry matter yeild of first and second cut, Bami was the best cultivar. This cultivar also located in a distinct class based on the Duncan classification method. UPGMA cluster analysis divided the cultivars into six groups by cophenetic coefficient of 84%. The cultivars Bami (20319) and 2421 each located in a separate group. Although cluster analysis based on the significant characters divided the cultivars into five groups, the results were similar to the previous classification, so that the cultivar number 20319 (Bami) located in a separate group. Cophenetic coefficient was 82% in this analysis, implying a good fitness of the clustering method.