GENETIC VARIABILITY OF GRASSCUTTER (Thyronymus swinderianus L) IN IMO STATE USING RANDOM AMPLIFIED POLYMORPHIC DNA (RAPD) MARKERS

Abstract

Genetic variability of grasscutter (Thyronymus swinderianus L) was investigated using random amplified polymorphic DNA markers in Imo state. A total of four primers of arbitrary sequence were used and all of them generated reproducible, scorable and polymorphic bands. The highest percentage polymorphic band was recognized for primer OPA19 (100%) while the lowest percentage of polymorphic band was recognized for the primers OPA14 (50%). The observed number of alleles (Ne) had values ranging between 1.50±0.52 – 2.00±0.00 for OPA14 and OPA19 respectively. Similar trend was observed for Ne, H, and I with values ranging between 1.39±0.42 for OPA14 to 1.81±0.14 for OPA19; 0.22±0.23 for OPA14 to 0.44±0.05 for OPA19 and 0.31±0.33 for OPA14 to 0.64±0.05 for OPA19 respectively considering the genetic diversity indices for combined loci. Similarly, considering the genetic diversity indices between the grasscutter population/strain, the light strain had the higher value for all the diversity indices; Na (1.71), Ne (1.56), H (0.25) and I (0.44) than the dark strain; Na (1.61), Ne (1.39), H (0.25) and I (0.34). The study therefore suggested that RAPD can be successfully utilized for detecting genetic variability among the studied grasscutter population and there could be selection within and between the studied populations for genetic improvement.