Assessment of genetic diversity in quality protein maize(QPM) inbreds using ISSR markers

Genetic diversity of 49 maize inbreds was assessed using twelve ISSR primers. A wide variation in PCR products was revealed in terms of size (280 to 3000 bp), extent of polymorphism (94.87%) and number of bands (4-9). As a whole, 78 ISSR bands were produced (including four monomorphic bands) with an average of 6.5 bands per primer and the maximum number of bands (9) being produced by primer OUAT-8. Five ISSR primers (OUAT-8, OUAT-9, OUAT-15, OUAT 17 and OUAT-18) revealed higher PIC value (around 0.70) along with 100% polymorphism indicating better allelic diversity. While, ISSR primer OUAT-15 revealed higher number of polymorphic bands (8) with 100% polymorphism as well as considerably high PIC and Rp values. Thus, such an informative and discriminative primer is of immense value for the study of genetic diversity in a set of maize genotypes. The similarity index values ranged from 0.3 to 0.9 with an average of 0.522 and BQPM-1-14 maintained the highest genetic distance as revealed from its lowest average similarity coefficient value (0.393) with rest of the genotypes. BQPM 1-14, BQPM 1-8, BQPM 3-10, BQPM 6-8 and B 1110-7-2 were identified to be highly divergent among the test inbreds which could be sorted out as valuable materials for heterosis breeding for production of single cross hybrids.