Evaluation of maize (<i>Zea mays</i> L.) accessions using line x tester analysis for aluminum and manganese tolerance

Abstract

Soil acidity is a limiting factor severely affecting the growth and yield of maize. The present study aimed at estimating the breeding value of inbred lines and to assess the test-cross performance of the hybrid maize under acid soil conditions. A line x tester analysis involving 63 test-crosses generated by crossing 20 maize inbred lines with 3 testers and between testers themselves, and 1 standard check was investigated during the cropping season 2012 in two contrasted regions with aluminum and manganese toxicity in Cameroon. Both treatments, acid soil and non-acid soil, using dolomitic lime were conducted in a randomized complete block design with 3 replications. Seven hybrids producing high grain yield (4.27 to 9.88t/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 showed that the tolerance to aluminum toxicity was controlled by additive effects of genes while on acid soil with manganese toxicity, the contribution of non-additive effects of genes was dominant.

Keywords: Inbred lines, hybrids, acid soil, GCA, SCA, humid forest zones