Assessment of genetic variation and population structure in Indian Gladiolus cultivars inferred from molecular markers

Genetic variability and relationships in 54 genotypes belonging to nine Gladiolus cultivars were determined using single primer amplification reaction methods (Random Amplified Polymorphic DNA—RAPD; Directed Amplification of Minisatellite DNA—DAMD; and Inter Simple Sequence Repeats—ISSR). A total of 30 primers (10-RAPD, 10-DAMD and 10-ISSR) resulted into 230 DNA fragments, of which 177 (75.8 %) were polymorphic in nature. The polymorphic information content (PIC = 0.18), resolving power (RP = 11.2) and marker index (MI = 11.4) was found to be highest in ISSR markers. To understand the extent of genetic variability among the Gladiolus cultivars, the cumulative dataset were used to generate UPGMA dendrogram. All the 54 genotypes clustered together in nine broad clusters, revealing that the clustering pattern of the genotypes were as per their cultivars. PCoA analyses also revealed similar clustering patterns along the axis and therefore corroborating the grouping of genotypes in UPGMA dendrogram. The STRUCTURE analysis showed the admixture of alleles and resulted into eight genetic populations. The present study demonstrates the efficiency and discriminatory potential of an individual as well as cumulative analysis of RAPD, DAMD and ISSR markers to estimate the genetic variability and inter-relationships among indigenously developed Gladiolus cultivars. Furthermore, documentation and preservation of genetically diverse Gladiolus germplasm could be an important source for improvement of this floricultural crop.