Napier grass commonly referred to as elephant grass, or Uganda grass and scientifically known as Cenchrus purpureus, is one of the most important fodder crops for the small-scale dairy farmers in the high- and medium-potential dairy production areas of eastern, central and southern Africa. Its high productivity, quality and availability all year-round under irrigated conditions make it readily available and suitable to feed livestock. It has been used in soil conservation and in an agricultural pest management strategy. A recent study, published in Nature’s Scientific Reports, has identified significant diversity in a Napier grass collection.

Researchers from Ethiopia, Kenya and the Republic of Korea, examined the diversity in the Napier grass populations maintained at the International Livestock Research Institute (ILRI) forage gene bank and the Brazilian Agricultural Research Corporation (EMBRAPA) using an advanced genomic method, genotyping by sequencing (GBS). The analysis revealed, for the first time, that there is a significant amount of genetic diversity contained within the collection which offers opportunities for the selection of new and improved varieties. The assumption is that this highly productive grass is only grown in the tropics, below 2,000m in areas with more than 1,000mm of rainfall a year.

Chris Jones, leader of the Feed and Forage Development program at ILRI and the corresponding author of the study said: ‘The general information available to smallholder farmers on Napier grass varieties is not entirely accurate since not all Napier grass is the same and our studies have shown that there is significant variation within the species that can lead to higher productivity when fed to livestock. What we need to do now is to fill the gaps through a combination of collecting more material and crossing individuals to start plant breeding. We will then apply our molecular tools to tap into that diversity and identify and deliver new varieties adapted to produce across a range of production systems and environments.’

The researchers are currently progressing field trials that are designed to look at the nutritional quality and agronomic performance of this collection both in irrigated and water-stressed environments. As part of this process, they have identified varieties that consistently produce forage of high quality, both in terms of digestibility and crude protein (feed traits which underpin animal performance), respond well to irrigation and produce significantly higher yields and continue to produce well when water is limited.

The researchers have created two subsets out of the diversity analysis for more targeted testing in irrigated and rainfed systems. These accessions are available at ILRI and EMBRAPA and may be of interest to fellow scientists working in areas such as climate change adaptation, mixed crop-livestock production systems, and to extension agents who may want to test their suitability and use in different production systems.

For additional information and request for Napier grass varieties, contact Chris S. Jones: c.s.jones@cgiar.org or ILRI’s forage gene bank manager, Alieu Sartie: a.sartie@cgiar.org

Read the full publication: Genotyping by sequencing provides new insights into the diversity of Napier grass (Cenchrus purureus) and reveals variation in genome-wide LD patterns between collections.

Find out more about Napier grass research in ILRI science papers

Opportunities for Napier grass (Pennisetum purpureum) improvement using molecular genetics

Molecular markers as a tool for germplasm acquisition to enhance the genetic diversity of Napier grass (Pennisetum purpureum) collection