Evaluation of genetic diversity of Freesia hybrida genotypes using ISSR marker

The objective of present study was to evaluate the genetic diversity within 23 genotypes of Freesia hybrida including 6 parents and their 17 F1 hybrids, using 10 ISSR primers in order to utilize such diversity in breeding program of this plant. 

After extraction of genomic DNA from fresh leaves and amplification of marker regions by the PCR, followed by the electrophoresis, a matrix of binary data was created based on scoring of electrophoretic bands. Marker parameters including number of polymorphic loci, polymorphism information content, effective multiple ratio, resolution power index, and marker index as well as genetic variation indices including observed number of alleles, effective number of alleles, Nei's gene diversity index, and Shannon's information index were calculated by using the ISSR marker data. Principle components analysis based on the Jaccard similarity coefficient with UPGMA algorithm were done followed by the cluster analysis using Dice coefficient and based on Ward’s grouping method. 

Out of 110 amplified loci of the 10 ISSR markers, the mean of polymorphism percentage 94.7% within the used genotypes was estimated. Maker IS-HB11 showed maximum number of polymorphic loci (12), effective multiple ratio (7.93), resolution power index (7.83), and marker index (2.67) as well. Cluster analysis grouped genotypes into four clusters, which was confirmed by the result of principle component analysis. 

Relative high value of the polymorphism information content (0.368), showed that the ISSR makers utilized in present study were genetically well informative regarding to the number of identified alleles and their distribution in the genome of Freesia. Based on the gene diversity indices, there was no significant difference between the parental genotypes and the F1 hybrids in terms of genetic variation. However, the level of this variation was acceptable and is capable to be utilized for breeding program in this plant.