Genetic Diversity of Spathoglottis plicata Blume Orchid Variant Based on Inter-Simple Sequence Repeat (ISSR) Molecular Marker

The aim of this research is to determine the level of genetic diversity of in vitro cultur Spathoglottis plicata variants derived irradiated (mutants) and without irradiation (wild type) seeds. This research is an observation study to detect of genetic diversity of plant variants based on ISSR molecular markers. DNA isolation and quantification was carried out and DNA amplification was then done by Polymerase Chain Reaction (PCR) method with seven ISSR primers. The data were analyzed by the GenAlex program to analyse the genetic distance, percentage of DNA polymorphism and scattered diagram. The NTSYSpc2.0.2 program was used to calculate similarity index and cluster dendrogram by Unweighted Pair-Group Method Using Arithmetic Average (UPGMA). The results showed that the genetic diversity level of Spathoglottis plicata variants based on the percentage of plant polymorphism of variants derived from irradiated seed culture results was 92.57%, while wild type variant group was 44.78%, with an average total of 68, 66%. The largest source of genetic was contributed by inter-population diversity with a percentage of 69%. Genetic variation in the mutant plant variant group was higher than the wildtype plant group. The result of dendogram shows that S. plicata orchid variants were divided into 3 clusters where the second cluster consisting of a group of mutant plants has a similarity level score <60% which shows that this variant has the potential to develop into new varieties.