Identification of potential maize inbred lines through morphological and molecular heterotic grouping

This study was conducted to identify potential maize inbred lines for hybrid development through morphological and molecular heterotic grouping. A total of 120 test crosses developed using 60 inbred lines and two heterotic testers (LM-13 and LM-14) in a line × tester mating design (rabi, 2019–20) were evaluated for grain yield along with parental lines across 3 locations (Maize Research Center (MRC), Rajendranagar and Agricultural Research Station (ARS) at Karimnagar and Madhira, Telangana, India) during rabi, 2020–21. Molecular diversity among 62 parental lines was assessed using 30 simple sequence repeat (SSR) markers at the Institute of Biotechnology, Rajendranagar, Hyderabad, Telangana, India. Pooled analysis of variance revealed significant differences among genotypes across locations, indicating the presence of ample genetic variability for grain yield. Based on the heterotic group specific and general combining ability (HSGCA) method, the inbred lines were classified into two distinct heterotic groups, while molecular diversity analysis grouped them into 4 clusters, revealing substantial genetic divergence. The integration of both morphological and molecular analyses enabled the identification of 12 promising inbred lines common to both approaches; six lines (MGC-90, PFSR-51, GP-35, GP-111, BML-11 and BML-20) associated with tester LM-13 and six lines (PFSR-151, PFSR-46, MGC-15, MGC-137, PFSR-129 and PFSR-95) associated with tester LM-14. These diverse inbred lines hold potential for generating superior segregants in hybridisation and advancing precision breeding programmes in maize.