Hybridization of Indian Landraces and African Elite Composites of Pearl Millet Results in Biomass and Stover Yield Improvement under Arid Zone Conditions

Abstract

Pearl millet [Pennisetum glaucum (L.) R. Br.] is an important cereal crop of arid and drier semiarid regions of south Asia and Africa valued for both grain and stover. Drought is the most common production constraint in these regions. Drought-resilient landraces are widely grown but their cultivation results in a yield penalty under favorable conditions. Both high productivity and adaptation to drought stress are essential for cultivars targeted for arid regions. This study was conducted to assess whether crosses between Indian pearl millet landraces and African elite composites offer any advantage over landraces. Twenty-five crosses produced by hybridizing five Indian landraces with five African elite composites were evaluated for three seasons (2006–2008) at Jodhpur, India. Improvement in crosses was quantified by measuring midparent heterosis and differences between crosses and their parental populations. On an average, crosses had significantly higher biomass and stover yield than both landraces and composites but had grain yield similar to the parental populations. There was differential magnitude and direction of midparent heterosis for various traits: heterosis was positive for biomass (10%) and stover yield (12%) but negative for harvest index (–7%). Although there was little overall heterosis for grain yield, a few individual crosses had significant grain yield heterosis up to +33%. More than one-third of the crosses had greater grain and stover yields than their landrace parent, resulting in a mean advantage of 18% in their total crop value over landraces. These results indicate that hybridization of Indian landraces with elite composites based on African germplasm is an attractive and useful strategy to enhance biomass, stover, and grain productivity under drought-prone conditions.