Line x Tester Analysis and Potential for Aluminum and Manganese Tolerance in an International Collection of Maize

Soil acidity is a limiting factor that has a significant impact on maize growth and yield. The aim of this study was to determine the breeding value of inbred lines and to evaluate the hybrid maize test-cross output under acid soil conditions. During the 2012 cropping season in Cameroon, a line x tester analysis involving 63 test-crosses created by crossing 20 maize inbred lines with 3 testers and between testers themselves, as well as 1 standard check, was conducted in two contrasted regions with aluminium and manganese toxicity.. Both acid and non-acid soil treatments with dolomitic lime were tested in a randomised full block design with 3 replications. Seven hybrids producing high grain yield (4.27 to 9.88 t/ha), with high specific combining ability (SCA) and slow rate of yield loss were discovered such as tolerant for both types of acidic soils. Likewise, four inbred lines (ATP-46, 87036, and Cam Inb gp117, C4SRRA7) with high general combining ability (GCA) were retained as good progenitors. The GCA and SCA effects revealed that additive effects of genes mediated resistance to aluminium toxicity, while non-additive effects of genes dominated on acid soil with manganese toxicity. However, for a potential extension, a molecular characterization of the selected varieties will be needed.