Assessment of genetic diversity and population genetic structure of Carthamus species and Iranian cultivar collection using developed SSR markers.

This experiment was conducted to assess genetic relationships among safflower genotypes from different geographical regions of Iran and other countries using newly developed simple sequence repeat (SSR) markers. By enrichment method, 32 primer pairs were designed of which 18 pairs were able to detect polymorphism in 105 safflower cultivars from Carthamus tinctorius, C. oxyacanthus, C. lanatus, C. glaucus, C. boissieri and C. dentatus. The selected SSR primers amplified a total of 59 alleles with an average of 3.27 alleles per locus among the cultivars and the average values of gene diversity, heterozygosity and PIC were 0.45, 0.37 and 0.39, respectively. Neighbour-joining cluster analysis based on Nei's genetic distance categorized populations of Carthamus in six major clusters; all wild accessions were grouped differently from cultivated genotypes. Cluster analysis significantly distinguished C. oxyacanthus genotypes in different categories: centre (Arak), northeast (Azarbaiejan), east (Kermanshah) and southeast (Shiraz, Chaharmahal and Kohgiluyeh). The presence of C. boissieri and C. glaucus in one cluster appeared to be in close relationship between each other, indicating a common ancestor. The results revealed that C. dentatus discriminated from the species with n = 10 chromosomes, C. boissieri and C. glaucus assigned in to separate subsection. In summary, this study has shown that domesticated and wild genotypes were clustered into two major groups indicating these markers as appropriate tools to amassment genetic diversity and genome mapping.

IGF-I gene polymorphism, but not its blood concentration, is associated with milk fat and protein in Holstein dairy cows.

We estimated the allele and genotype frequencies of IGF-I/SnaBI gene polymorphism and the concentration of this protein in Holstein dairy cows. We also examined the association with milk yield (305-day milk yield) and milk components (fat and protein percentage, and 305-day milk protein and fat yield). Blood IGF-I levels were measured and genotyping was performed on 250 Holstein cows of four different herds. In the association studies, traits of interest were analyzed using the GLM procedure of SAS; means of the IGF-I level among genotypes were compared by the LSMeans test. The AB and AA genotypes were the most (0.583-0.661) and least (0.083-0.192) frequent in the herds, respectively; the frequency of the BB genotype ranged from 0.201 to 0.333. The frequency of the A allele ranged from 0.375 to 0.495, while the frequency of the B allele ranged from 0.504 to 0.625, being the dominant allele. The mean level of IGF-I was 107 +/- 22 ng/mL for all groups, without any significant correlation with the production traits. Association of IGF-I/SnaBI genotypes with percentage of fat and protein in the milk was relatively high (P < 0.1 and P < 0.05, respectively); the AB genotype was superior to AA and BB genotypes. We concluded that this marker should be considered for milk component selection in Holstein dairy cattle.