RAPD analysis for genetic polymorphism in bread wheat (Triticum aestivum L. Em Thell) genotypes varying for grain protein content

Abstract

Genetic polymorphism was investigated among nine spring wheat genotypes, differing in grain protein content, including C-306M10 (mutant of drought tolerant variety C306), DI 8, DI 9, DI 16, DI 20, DI 716, DI 717, DI 728 (near isogenic lines) and HGPC (from Wheat x Rye crosses) using 55 RAPD primers. Out of 55 primers used, only 36 amplified and generated 2(OPG08, OPD05) and 12 (OPD02) bands. A total of 342 amplified products were observed, of which 168 were polymorphic (49.12%) while 174 were monomorphic. The primer OPC-05 and OPC-07 revealed 92.86% and 80.00% polymorphism, respectively and these primers were most useful in characterization of nine wheat genotypes included in this study. The primer OPG-08 showed no polymorphism. It is concluded that the primers OPC-05 and OPC-07 were very effective in distinguishing wheat genotypes in the present study. Twenty six RAPD primers produced a total of 48 unique bands for high protein content that were either present or absent in HGPC a-high grain protein genotype and thus can be used in wheat improvement through marker-assisted selection (for the bands which are unique by their presence). Data (RAPD analysis) were used to generate the similarity coefficients using `siMqual' subprogram of software NTSYS-PC. The similarity coefficient values ranged from 0.97(DI8 and DI9) to 0.68 (DI9 and HGPC), indicating high genetic variability among the selected wheat genotypes. The cluster analysis and principle component analysis broadly divided the wheat genotypes into two groups and showed that DI 9 and HGPC were most divergent genotypes.