Identification of heterotic maize hybrids with post flowering stalk rot resistance utilizing tropical and temperate inbred lines

Maize (Zea mays L.) is a staple cereal crop contributing to global food security. The increasing demand for maize in food and feed industries necessitates enhancing the yield by utilizing diverse inbred lines with multiple stress tolerance. Forty inbred lines, including 30 tropical and 10 temperate lines, were crossed with two diverse testers, CML 286 and CML 451, during kharif 2021 for heterotic grouping of post-flowering stalk rot (PFSR) resistant lines with high yield potential. The heterotic group-specific and general combining ability (HSGCA) method classified them into three groups viz., A of CML 286 with 19 lines, B of CML 451 with 13 lines and an undetermined group with eight lines. Six lines of group A (five tropical lines PFSR 393, PFSR 204, GP 327, PFSR 145, GP 82 and one temperate line GP 329) and five lines of group B (three tropical lines GP 36, GP 69, GP 86 and two temperate lines GP 83, GP 107) with highly significant HSGCA effects were crossed to produce 30 single cross hybrids during Rabi 2021-22. Screening of these 11 inbred lines from both groups A & B identified two diverse inbred lines viz., tropical GP 36 and temperate GP 83 with PSFR resistance, which can be used as potential donors. The general combining ability (GCA) effects identified three tropical inbred lines, PFSR 145, PSFR 393, GP 36 and one temperate inbred GP 107 line, as good general combiners for early maturity and two temperate inbred lines, GP 329 and GP 107, as best general combiners for grain yield with moderate PFSR resistance demonstrating the potential of temperate and tropical maize lines for increased yield and PFSR resistance. The specific combining ability (SCA) effects identified five potential hybrids GP 329 × GP 83, GP 329 × GP 86, PFSR 393 × GP 107, GP 82 × GP 83 and PFSR 145 × GP 86 with high per se performance for grain yield for future use in maize hybrid breeding programmes with PFSR resistance.