DNA fingerprinting in African marigold (Tagetes erecta L.) genotypes using ISSR and URP markers

Genetic diversity of 22 marigold (Tagetes erecta L.) genotypes was evaluated with Inter Simple Sequence Repeats (ISSR) and Universal Rice Primers (URP) markers. A total of 31 molecular markers comprising of 19 ISSR and 12 URP markers were utilized for the study. A total of 184 amplicons were amplified using 19 ISSR primers, out of which 171 (92.73%) were polymorphic. The polymorphic information content (PIC) ranged from 0.23 to 0.47 with an average of 0.34. The resolving power (RP) ranged from 7.00 to 16.00 with average of 11.20. The marker index (MI) ranged from 0.77 to 4.83 with an average of 2.93. In case of URP markers, a total of 131 amplicons were amplified of which 122 (93.08%) were polymorphic with 12 URP primers. The polymorphic information content (PIC) ranged from 0.17 to 0.39 with an average of 0.32. The resolving power (RP) ranged from 8.82 to 22.45 with average of 13.75. The marker index (MI) ranged from 0.55 to 5.87 with an average of 3.17. The Jaccard's similarity coefficient ranged from 0.33 to 0.81 in ISSR markers and 0.33 to 0.86 for URP markers which suggests a wide range of genetic divergence for marigold genotypes. UPGMA method was used for cluster analysis which categorised 22 genotypes in two main clusters at 0.44 similarity coefficient in both ISSR and URP markers. The two male sterile lines formed a distinct group as confirmed through both the marker systems.