Heterotic grouping of QPM inbred lines and quality profiling based on genetic and molecular markers

Abstract

The present investigation entitled Heterotic grouping of QPM inbred lines and quality profiling based on genetic and molecular markers was undertaken to study combining ability effects for yield and quality traits, understand the heterotic pattern and estimate the genetic relationship and diversity among QPM inbreds using molecular markers in quality protein maize. Ten QPM inbred lines were hybridized following Griffingand#8223;s Method 2, Model 1 in a half diallel fashion. Experimental materials comprising of ten inbred lines, forty five single cross experimental hybrids, three hybrids along with two standard checks were evaluated in and#945;-RBD with two replications during kharif 2016 (E1) and 2017 (E2) at Palampur (L1) and Akrot (L2). The analysis of variances indicated significant differences among genotypes for grain yield per plant and other component traits in all the environments. Also, significant differences for environment (E) and lines × environment interaction for most of the traits except cob girth indicated a definite role of environment on the performance of genotypes/crosses. Variances due to GCA, SCA and their interaction with environment were significant for most of the traits under Palampur and Akrot conditions, indicating the importance of testing parents as well as hybrids across environments. On the basis of per se performance, heterosis and combining ability for grain yield per plant and other component traits, the cross combination P1 × P7 at both the locations was found best, whereas P3 × P8 and P1 × P4 under Palampur conditions were found best. Parent P1 and P5 were the most promising general combiners for grain yield per plant and most of the yield component traits at both locations. For most of the traits, there was preponderance of non-additive gene action which reaffirms the importance of heterosis in maize. At molecular level, 28 SSR primers amplified 97 polymorphic alleles with an average of 3.46 alleles per primer. Size of amplified alleles ranged from 50 to 480 bp. Mean polymorphic informa