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

Abstract

To examine concurrence between yield based and SSR marker based heterotic grouping of latematuring maize inbred lines. A total of 45 F 1 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. 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 latematuring maize inbred lines into t h r e e h e t e r o t i c g r o u p s. Similarly, molecular genetic d i v e r s i t y a n a l y s i s a l s o categorized the inbred lines into three major clusters. However, correlations between SCA effects and genetic distance were low (r=0.161) for grain yield. 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.

Advances in Research on the Mechanism of Heterosis in Plants

“…Chen et al (2020) found that the correlation between GD and heterosis in eucalyptus is poor by EST-SSR markers. Similarly, some studies have shown that GD also does not predict heterosis levels in maize, wheat and melon (Dreisigacker et al, 2005;Maruthi et al, 2019;Asaf et al, 2021). But Tian et al (2017) argued that the GD estimated using random SSR and sequence related amplified polymorphism (SRAP) primers is not correlated with the heterosis of Brassica napus, whereas the GD estimated by the F1 heterozygous marker is highly correlated with the number of pods, thousand-seed weight, and single-species yield of this plant.…”