Study of genetic variation in sesame (Sesamum indicum L.) using agro-morphological traits and ISSR markers.

This research was conducted to study the genetic variation among eighteen genotypes of sesame (Sesamum indicum L.) collected from various agro-climatic regions of Iran along with six exotic genotypes from the Asian countries using both agro-morphological and ISSR marker traits. The results showed significant differences among genotypes for all agro-morphological traits and a relatively high genetic coefficient of variation observed for number of fruiting branches per plant, capsules per plant, plant height and seed yield per plant. Cluster analysis based on these traits grouped the genotypes into five separate clusters. Larger inter- than intra cluster distances implies the presence of higher genetic variability between the genotypes of different groups. Genotypes of two clusters with a good amount of genetic divergence and desirable agronomic traits were detected as promising genotypes for hybridization programs. The 13 ISSR primers chosen for molecular analysis revealed 170 bands, of which 130 (76.47%) were polymorphic. The generated dendrogram based on ISSR profiles divided the genotypes into seven groups. A principal coordinate analysis confirmed the results of clustering. The agro-morphological traits and ISSR markers reflected different aspects of genetic variation among the genotypes as revealed by a non significant cophenetic correlation in the Mantel test. Therefore the complementary application of both types of information is recommended to maximize the efficiency of sesame breeding programs. The discordance among diversity patterns and geographical distribution of genotypes found in this investigation implies that the parental lines for hybridization should be selected based on genetic diversity rather than the geographical distribution.

Inheritance of flower color and spininess in safflower (Carthamus tinctorius L.).

Safflower (Carthamus tinctorius L.) flowers are used for coloring and flavoring food and also as fresh-cut and dried flowers. The most important characteristics which contribute to the ornamental value of safflower are flower color and spinelessness. The objective of this study was to determine the inheritance mode and the number of genes controlling spininess and flower color in some Iranian genotypes of safflower. The results indicated that the existence of spines on the leaves and bracts of safflower is controlled by a single dominant gene in which the spiny phenotype was completely dominant to spineless. In some crosses, flower color was controlled by two epistatic loci each with two alleles, resulting in a ratio of 13:3 in the segregating F2 population for plants with orange and yellow flowers. Also, other mechanisms of genetic control, such as duplicate dominance and duplicate recessive types of epistasis, were observed for flower color in other crosses that led to ratios of 7:9 and 15:1 for plants with orange and yellow flowers, respectively. The results suggest that for ornamental use or in the food dying industry, genotypes with orange or yellow flowers and without spines on the leaves and bracts can be produced.