Assessment of genetic diversity among 131 safflower (Carthamus tinctorius L.) accessions using peroxidase gene polymorphism (POGP) markers.

BACKGROUND: Safflower (Carthamus tinctorius L.) is an old oilseed crop with a 1.4 GB genome size and its flowers are used for food coloring, dyes and pharmaceutical industries. It was domesticated from its putative wild ancestor Carthamus palestinus about forty-five hundred years ago in the fertile crescent region.The current study was aimed to determine the genetic diversity, population structure and to check the applicability of iPBS-retrotransposons markers. METHODS AND RESULTS: Eleven POGP primers yielded 70 bands of which 61 were highly polymorphic with 87.14% polymorphism. A great level of genetic variation was examined with higher values of overall gene diversity (0.27), genetic distance (0.53), number of effective alleles (1.46), Shannon's information index (0.41) and polymorphism information contents (0.71). Analysis of molecular variance revealed high genetic variation with 79% within the population. The STRUCTURE, PCoA and Neighbor-joining analysis separated the safflower germplasm into 2 major populations and 1 un-classified population. The accessions which were from Asian countries i.e., China, Afghanistan, Turkey, Iran and Pakistan were genetically similar and clustered together in both populations A and B. The maximum genetic distance was measured 0.88 between Pakistan 26 x Pakistan 24. CONCLUSION: Findings of this research such as maximum diversity indices, higher PIC values showed the effectiveness and utility of POGP markers for the evaluation of genetic relationships among safflower accessions. The results of this study also showed that POGP markers are less effective compared to ISSRs, iPBS-retrotransposons and DArTSeq markers. AMOVA showed high genetic variation (79%) within a population and maximum genetic distance was found between the accessions Pakistan 26- Pakistan 24 and may be suggested as candidate parents for future breeding activities of safflower. The accessions from the fertile crescent region were clustered together and proved the origin of safflower domestication. This study highlights genetic variation among safflower germplasm and could be helpfull for parental selection and planning for future breeding programs.

Determination of the effective radiation dose for mutation breeding in purple carrot (Daucus carota L.) and possible variations formed.

BACKGROUND: Plant breeding allows altering the genetic structure of plants to meet human needs. The use of radiation technology for inducing mutations and -thereby- new phenotypic variants has become increasingly common as a tool for developing new crops. The aim of this study was to determine the effective gamma irradiation dose for inducing mutations in purple carrot. METHODS AND RESULTS: Increasing gamma radiation doses [0, 50, 100, 200, 300, 400, 500, and 600 Gy] were applied to purple carrot seeds. The irradiated seeds were sown in pots and the emergence and survival rates of the seedlings were analyzed. Considering plant emergence (%) as a response variable, the LD50 dose was 387.5 Gy. Analysis of root length, root width (shoulder diameter) and plant height in control (0 Gy) and irradiated plants (50-600 Gy) revealed an inverse association between these morphological traits and radiation dose. SRAP and ISSR markers were used to identify DNA polymorphisms in irradiated and control plants. The range of amplicons per primer set revealed by ISSR and SRAP markers was 4-10 and 2-13, respectively. In the ISSR analysis of the irradiated carrots (for the 8 doses used), we obtained range values for the average Nei's gene diversity, Shannon's information index, and polymorphism information content (PIC) of 0.13-0.25, 0.20-0.35, and 1.39-1.67, respectively, whereas in the SRAP analysis, the range values for these parameters were 0.15-0.25, 0.23-0.37, and 0.43-0.58, respectively. Cluster analysis revealed three main groups; (a) non-irradiated (control) plants, (b) plants from the 600 Gy dose, and (c) a third group with two subgroups: one with individuals from the lowest irradiation doses (50-200 Gy) and a second group with individuals from the highest irradiation doses (300-500 Gy). CONCLUSIONS: This is the first report on determining effective mutagen doses and genetic characterization of induced mutagenesis via gamma irradiation in purple carrot. ISSR and SRAP markers were successful in detecting variations among different levels of mutagen doses.

Exploring the genetic variations and population structure of Turkish pepper (Capsicum annuum L.) genotypes based on peroxidase gene markers.

Capsicum is thought as one of the most diverse and significant genera due to its varied uses in different parts of the world. In this study, we worked with a total of 71 pepper genotypes from different locations of Turkey to investigate the level of their diversity using the peroxidase gene polymorphism (POGP) markers to reveal their population structure. For this purpose, 14 peroxidase primer pairs were used. They produced 139 bands (mean = 9.9 bands/primer), of which ~ 85.6% were polymorphic in the all germplasm collection. Polymorphism information content (PIC) ranged between 0.48 and 0.97 with an average of 0.75. Range and mean values for gene diversity (h) were 0.09-0.22 and 0.17, respectively. Shannon's information index (I) per POGP marker ranged from 0.18 to 0.35 with a mean of 0.29. Using three clustering methods (unweighted pair-group method with arithmetic means, principal coordinate analysis, and STRUCTURE) revealed a clear separation of all the C. annuum accessions from C. frutescens and C. chinense accessions in our study. Clusters did not establish an association between the accessions and their geographical origin. This is the first study exploring the population structure through the genetic diversity of Turkish peppers from different regions of the country based on the peroxidase gene markers.