Genetic Variation within the Aquatic Plant Species Cryptocoryne xPurpurea in Tasik Bera, Malaysia as Revealed by RAPD Analysis

Genetic variation of two natural populations of the rare aquatic plant species Cryptocoryne xpurpurea were investigated using random amplified polymorphic DNA (RAPD) markers. Four random primers generated a total of 57 bands and 49 (86%) of them were polymorphic indicating considerable genetic variation at the species level. A Neighbor-Joining (NJ) tree constructed using genetic similarities data separated the samples into two distinct groups each representing a single population. Two-dimensional PCO graph generated from genetic similarity data was also in agreement with the NJ tree topology. Analysis of molecular variance (AMOVA) showed that a large proportion of the genetic variation (67%) resided between populations while only 33% of the genetic variation resided within population. The low level of genetic diversity among individuals was likely generated from somatic mutation since this hybrid species exhibited high pollen sterility. However, separate hybridization events followed by population isolation and subsequent independent accumulation of somatic mutations could have resulted in the high genetic variation between populations.