Heterotic grouping of late-maturing maize inbred lines based on combining ability and molecular marker studies

ABSTRACT

Aim: To examine concurrence between yield based and SSR marker based heterotic grouping of late-maturing maize inbred lines. Methodology: A total of 45 F1 crosses derived from 10x10 diallel mating scheme were evaluated along with their parents and hybrid checks across two locations (New Delhi and Dharawada). To group the inbred lines at molecular level, 35 polymorphic SSR primers were used for PCR amplification of repeat sequences from the genomic DNA of each inbred isolated by CTAB method. Cluster analysis was carried out by using NTSYS-pc- 2.02. Results: Analysis of variance revealed significant (P<0.01) variation among the parents and their hybrids across two locations for all the traits. The yield SCA classified 10 late-maturing maize inbred lines into three heterotic groups. Similarly, molecular genetic diversity analysis also categorized the inbred lines into three major clusters. However, correlations between SCA effects and genetic distance were low (r=0.161) for grain yield. Interpretation: Heterosis prediction with the help of molecular markers alone was not found effective. Further, field-testing can be complimented with molecular markers for the elimination of inferior crosses.