Genetic Diversity and Hybrid Purity Analysis of Pearl Millet Using Molecular Markers

The fingerprinting of pearlmillet hybrids and identification of their genetic relationships Pearl millet [Pennisetum glaucum (L) R. Br.] is one of the widely grown cereal crops in the arid and semi-arid region of India. In present investigation, six pearl millet hybrids viz., AHB-1666 (released hybrid) and AHB-1214, AHB-1157, AHB-1199, AHB-1231, AHB1240 (results of desirable crosses and hybrid are under pipelines for release) were screened with eleven RAPD primers and ten SSR markers. All the primers found highly polymorphic (except Xpsmp-2248 and m13_Xpsmp2229) and reproducible, generated distinct and polymorphic banding patterns. These primers enabled the assessment of genetic diversity and hybrid purity. The OPA-1 identified five hybrids by producing two male parent specific amplicons and three female specific amplicons and OPD-20 produced male parent specific amplicons of size ~300bp and ~ 250bp in two hybrids AHB-1666A, AHB-1240 respectively and one female parent specific amplicons of size 1kb and 200bp in two hybrids AHB-1199 and AHB-1231 respectively. Xpsmp-012 was found to be useful in identifying hybrid AHB-1214 and AHB-1157 with their respective female parent by generating female specific amplicons of size 400bp and 200bp (for AHB-1214) and 200bp (for AHB-1157). Based on RAPD and SSR dendrogram the percent similarity using Dice coefficient amongst lines was ranged between 73-97% and 72-95% respectively. The genetic similarity values retrieved from RAPD data ranged from 0.60 to 0.95 whereas genetic distance values ranged from 0.02 to 0.39. The genetic similarity values retrieved from SSR data ranged from 0.52 to 0.95 with an average of 0.21. The PIC values of eleven polymorphic RAPD markers ranged from 0.18 to 0.24 with an average of 0.20. RAPD primer OPA-11, OPD-10 and OPM-7 were observed to be most informative with the PIC value of 0.24 which significantly determined genetic relatedness among hybrids and parental lines. The PIC values of ten SSR markers ranged from 0.00 to 0.32. Based on combined RAPD and SSR data, average of 65.62% polymorphism was observed on the basis of banding patterns of each genotype and genetic distance values ranged between 0.04 and 0.362 with an average of0.21. The graphical result of Principle Co-ordinate Analysis was confirmation of results of genetic diversity and purity of hybrid with its parental lines. K e y w o r d s