Single-cross pearl millet hybrids are widely grown in India, but this cultivar type has not been adopted in Africa. Hybrids from India have proven to be highly susceptible to downy mildew disease in Africa, the continent where the disease originated. We investigated an alternative strategy of growing topcross hybrids where both the parents are of African origin and both are only partially inbred. We investigated root characteristics – length, diameter, area, volume and dry weight – under drought stress and well-watered controlled conditions in genotypes that included potential parents of topcross hybrids. Several, including population Civarex 06_05, had better developed roots under drought while also having good roots under more favourable conditions. Some of these genotypes were backrossed to a male-sterile line based on the A4 cytoplasm to produce male-sterile populations with stable male sterility. Civarex 06_05 had good combining ability when used as a female parent and produced high-yielding topcross hybrids. Two of the topcross hybrids were on restorer populations Toroniou, originating from Mali, and Maiwa from Nigeria. On the experimental station and in farmers’ fields, one was much superior in yield to the best local alternatives and both had superior downy mildew resistance. Current efforts on the seed production of these topcross hybrids are described, and the constraints to the commercialisation in Mali of promising topcross hybrids are discussed.

Both stover and grain are important considerations in the adoption of the new pearl millet (Pennisetum glaucum) cultivars in crop–livestock farming system in north-west India. Local landrace germplasm contains many of the traits needed to breed new cultivars, which met such requirements. We evaluated 169 pearl millet landraces to assess their potential for breeding new open-pollinated varieties, and measured heterosis in landrace testcrosses to evaluate their potential for topcross hybrids breeding. There were significant differences among landraces in their total biomass, grain yield and stover yield. A high accumulation of biomass, followed by its efficient partitioning, was crucial in determining grain productivity under arid zone. There was also no trade-off between stover and grain productivity and several landraces outperformed check cultivars in both grain and stover yields. The manifestation of heterosis in the landrace-based topcross hybrids varied for different traits. Significant heterosis for biomass, grain yield and stover yield was observed in specific male-sterile seed parent × landrace-based pollinator combinations. Utilization of landraces in variety development and topcross hybrids breeding programmes targeting north-western India or similar regions are discussed.