Testcross performance of doubled‐haploid lines developed from European flint maize landraces

Abstract

With 1 figure and 6 tables Abstract In maize ( Zea mays L.), as in other cross‐pollinated crops, a high mutational load of deleterious recessive alleles hampers the use of landraces in hybrid breeding. The in vivo doubled haploid (DH) technology meanwhile offers great promise in purging such alleles. This approach was employed to three European flint type landraces. Eighty DH lines were evaluated for testcross performance under three farming conditions. Mean testcross performance of DH lines was similar to that of their parental landraces but 22–26% lower than that of present elite flint lines. Highly significant genetic variance existed in each of the three DH‐line groups. Coefficients of genetic variation ranged from 6.7 to 7.4. DH‐lines derived from ‘Lucq de Béarn’ displayed specific adaptation to N deficiency. The 10% (out of 80) best DH lines surpassed the first‐cycle lines by 11% in testcross grain yield and remained only 13% below the elite lines. Altogether, the DH approach proved to be a highly effective tool for gaining access to the hitherto hardly tapped broad genetic diversity of landraces in research and breeding.