Since the production of maize hybrids needs to selection and crossing of desirable inbred lines, identification of lines with suitable genetic characteristics is one of the objectives of plant breeders. In this study, ISSR markers were used to assess genetic diversity in 100 inbred lines of maize. Sixteen primers amplified 81 loci, of which 78 (95. 12 %) were polymorphic. The maximum and minimum number of polymorphic bands were produced by UBC825 (8 loci) and UBC811 (2 loci) primers, respectively. The polymorphic information content (PIC) ranged from 0. 65 (UBC849) to 0. 93 (443), with an average of 0. 77. Cluster analysis based on Jaccard’ s similarity coefficient and complete linkage algorithm categorized the studied lines into 3 main clusters. The analysis of molecular variance using ISSR data showed that 9% of the variation was explained by the variation among population and 91% by the variation within population. The results showed that the ISSR markers capable to display a high degree of polymorphism among lines and are useful tools for fingerprinting and categorizing of maize genotypes into different groups. This feature can be used in determining heterotic groups and prediction of heterosis in maize hybrid production.

Considering the economic importance of tobacco and its role as a model plant in molecular researches, in the present study, 50 tobacco genotypes from Barley and Virginia group were evaluated. In order to determine of genotype, 21 primer combinations of AFLP were used.According to the results, out of 480 total numbers of bands with average of 17.76 bands for each combination, 373 bands showed polymorphic pattern. Due to high polymorphic percentage of used marker (77.45%), it can be expected to consider, this marker as a powerful tool for assessment of genetic diversity in tobacco breeding programs. Investigation of Jaccard’s genetic coefficients revealed Badisher Burley E, Pennbel69, R9 and Coker 176 had the highest genetic distances than the others. Therefore, it seems the genotypes to be useful for breeding programs including hybridization and developing of segregating mapping population. The results of AMOVA showed 4% of the total genetic variation was estimated between two groups of Barley and Virginia flu-cured and 96% was related to within groups. Also diversity statistic revealed primer combinations of E060-M160, E070-M140, E070-M150, E070-M160, E080-M150, E080-M160, E100-M140 and E100-M150 were the most powerful markers in the evaluation and identifying of relationships among tobacco genotypes that can be considered in the other related studies.

Aloe barbadensisis perennial, monocotyledonous, fleshy plant belongs to Aloaceae family. In this study, somoclonal variations of regenerated A. barbadensis plants were investigated. The plantlets of forth subculture transferred to the soil for further study. The genomic DNAs of 40 regenerated plantlets were extracted and genetic variations were studied using SPAR markers including RAPD and ISSR primers. The amounts of Aloe gel also were extracted from regenerated A. vera plants. Average percentage of polymorphism, Shannon index, Nei's genetic diversity and number of effective alleles based on RAPD data were higher than genetic parameters obtained from ISSR data. NJ cluster and STRUCTURE plot based on molecular markers grouped regenerated plants to distinct clusters. AMOVA analysis also showed a significant (P=0.01) genetic distinction between studied groups. This result also confirmed differentiation of regenerated plants. The amount of Aloe gel in the four groups (based on clustering method) was compared by using analysis of variance (ANOVA). The results showed no significant (P=0.746) differences between the amount of gel in four group. In total, our findings showed somaclonal variations on genomic level while no significant differences were observed in amount of gel among regenerated Aloe plantlets.

Rice (Oryza sativa L.) is one of the most significant cereal crops, about 3 billion people, nearly half the world's population; depend on rice for survival and it offers up to 80% of daily energy intake in most of the Asian countries. Knowledge of the distribution, extent and pattern of genetic variation is useful for estimation of any possible loss of genetic diversity and its role in breeding programs. This work assessed the genetic diversity among 25 coastal rice populations of five regions of Kerala (South India) using 18 microsatellite markers. A mean PIC value of 0.37 and an average of 3.5 alleles per loci were observed. Mean Heterozygosity value of 0.29 and gene diversity value of 0.41 was attained. AMOVA demonstrated that genetic differentiation was significant at P<0.001 and FST index value of 0.035 was obtained. Of the total diversity, 57.76% was attributed within individuals, 38.71% was attributed among individuals within populations and 3.53% among populations. Information regarding the amount of genetic variations in these salt tolerant coastal accessions and genetic relationship between genotypes are essential for designing effective breeding programs. Especially, to meet the differentiated goals of plant breeding such as breeding for increasing yield, wider adaptation, desirable quality, pest and disease resistance.

Psoralea corylifolia as one of the medicinal herbs is used in the treatment of psoriasis, leukoderma and in many medicinal formulations. The genetic profiles and secondary metabolite content of 9 populations comprising of 72 accessions of P. corylifolia collected from different locations in western Maharashtra have been analyzed. Out of 40 RAPD primers, 21 primers were found polymorphic which gave 226 polymorphic loci with 99.56% polymorphism. The PIC value on an average was 0.228 indicating better discriminating power of RAPD’s in the present study. The cluster analysis and AMOVA showed more genetic variation within populations (76.47%) than between populations (23.53%). Methanolic extracts of dried seeds were analyzed for the total flavonoid and phenolic content while the acid hydrolysed ethanolic extracts were used for the estimation of isoflavonoids (daidzein and genistein) and coumarin (psoralen) content.Variation in the metabolite content was analyzed by one-way ANOVA and cluster analysis. An attempt has been made for the first to correlate the genetic and biochemical data in the populations of P. corylifolia.

This study was conducted to analyze genetic diversity in 15 natural populations of Iranian Agropyron pectiniforme using morphological traits and RAPDs (Random Amplification of Polymorphic DNA) molecular markers. Five primers out of the 10 were highly polymorphic and produced 128 polymorphic bands ranging in length of 500 to 2200 bp. According to AMOVA (Analysis of Molecular Variance) results, there was higher genetic variation between populations (53%) than within them (47%). Cluster analysis based on RAPD data categorized the populations into five clusters. PCoA (Principal Coordinates Analysis) results showed the first four coordinates accounted for 95% of the total variation. The scatter of populations based on the first two components was in agreement with cluster analysis results. There was no significant mantel correlation coefficient between molecular and geographical data indicating the classification of A. pectiniforme based on RAPD marker was not in accordance with geographical distribution. With regard to morphological traits, characters such as plant height and the number of stems per plants were considered as suitable parameters for selection and breeding programs. The two marker systems gave different estimates of genetic variability among populations. Finally, our findings demonstrated the feasibility of the RAPD technique for quantifying genetic distances among A. pectiniforme populations. It was concluded that, there is sufficient genetic variation between Iranian populations of Agropyron pectiniforme making these populations potentially useful for breeding improved varieties.

Chloroplast (cp) DNA polymorphism was analyzed in 14 populations of beech (Fagus orienta/is Lipsky) by PCR-RFLP and microsatellite (SSR) chloroplast markers. Two cpDNA inter genic regions DT and OA were amplified and treated with HaeIII and HinfI, respectively. The restriction fragments of the region DT did not show polymorphism among individuals within any population analyzed. However, among individuals within the analyzed populations of Asalem region and Neka-1400 population, polymorphism in the restriction fragments of the OA region was found. Three haplotypes, which could be phylogenetically ordered, were detected in this survey encompassing most of the natural range of the species. The high level of genetic differentiation (Gst=%69) together with the highly structured geographic variation contrast with low level of nuclear genetic differentiation measured in previous studies with isozymes and indicate a low level of gene flow by seeds. Among nine analyzed microsatellites, two showed polymorphism. Two and six different length variants at ccmp4 and ccmp7 loci were found, respectively, which combined into 10 different haplotypes. The distribution of haplotypes showed a very strong differentiation among populations (Fst=80%) and clear geographic structure. The analysis of molecular variance (AMOVA) showed that 52, 28 and 20% of the total cpSSR variation was attributable to differences among regions, among populations within regions and within populations, respectively. Clear evidence has been obtained that geographical distance is a major factor of population differentiation in the beech. This long-range pattern of variation was partially expected, given the huge natural range of beech and the existence of a gradient of variation in ecological factors. The high haplotype richness in the western populations, which found by the both markers in this investigation, is in accordance with this hypothesis that the beech forests of the Hyrcanian regions distributed from West to East.

The genus Sedlitzia (Amaranthaceae) includes four herbaceous and one shrubby species. Sedlitzia rosmarinus is resistant to salinity that plays an important role in soil conservation. In this research, RAPD molecular markers were used to evaluate the genetic diversity among 85 plant samples from 17 populations of S. rosmarinus. Five primers were used to perform RAPD reactions and a total of 400 DNA bands were obtained. After forming 0 and 1 matrix with the help of GenAlex 6. 41 and UPGMA methods using SHAN clustering model, NTSYS Ver. 2. 02 software was used to interpret RAPD analysis data. Molecular analysis of variance (AMOVA) was performed to estimate genetic diversity out of 85 individuals. Out of the total diversity, it was calculated that, the highest amount of genetic diversity i. e. 69% was related to intra-population and 31% to inter-population diversity, respectively.