Improving pearl millet drought tolerance

Three topcross pollinator populations (TCPs) were developed by selecting and intermating individual genotypes from within the F2:4 mapping families of a pearl millet population used for mapping quantitative trait loci (QTL) for drought tolerance. The 3 TCPs produced were selected according to: marker assisted selection (genetic composition at the drought tolerance WTL to constitute a MAS-based TCP); phenotypic selection (field performance, best 16, in the drought trials used to identify QTLs to constitute a phenotype-based TCP); and a random control (a random sample from within the mapping population to constitute a random TCP). The 3 TCPs were subsequently used as pollinators on 12 A-lines (male-sterile lines) to produce topcross hybrids. Compared to hybrids of the phenotype and random TCPs, the MAS TCP hybrids had better drought tolerant indices and grain yields in the drought-stressed environments, although they had lower yields in the irrigated control environment. Selecting simply on the basis of field performance under drought was ineffective, but MAS was able to produce improvement in this character.