ARS | Publication request: Genetic diversity among napier grass (Pennisetum purpureum Schum.) nursery accessions using AFLP markers

Submitted to: Plant Genetic Resources: Characterization and Utilization
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 22, 2009
Publication Date: September 22, 2009
Citation: Harris-Shultz, K.R., Anderson, W.F., Malik, R. 2009. Genetic diversity among napier grass (Pennisetum purpureum Schum.) nursery accessions using AFLP markers. Plant Genetic Resources: Characterization and Utilization. 8:63-70.

Interpretive Summary: Napier grass is a rapidly growing perennial grass used mainly for animal feed throughout the world and widely used in South America and Africa. Napier grass is also used as a windbreak for orchards or vegetable cropping areas, to prevent soil erosion, and has potential as a biofuel feedstock. Over the past 30 years a USDA-ARS napier grass nursery has been developed in Tifton, GA to collect accessions of napier grass from all over the world. Intraspecific crosses among some of these accessions have resulted in the release of ‘Merkeron’ and its progeny ‘Mott’. To further develop superior cultivars, a need exists to characterize the accessions of the napier nursery as many of the accession pedigrees are unknown. Using a DNA marker system called Amplified Fragment Length Polymorphism (AFLP) the napier grass accessions could be classified into five groups. Accessions from Kenya cluster into three groups and accessions of ‘Merkeron’ or derived from ‘Merkeron’ also form a group. The last group includes accessions from Puerto Rico and species crosses between napier and Pennisetum squamulatum. The classification of napier grass accessions into groups may provide potential heterotic groups for napier grass hybrids and napier x millet hybrids. These potential heterotic groups may lead to cultivars of napier grass and pearl millet with superior characteristics.

Technical Abstract: Pennisetum purpureum Schum. (napier grass) is a perennial grass used for forage especially in South America and Africa. The species has large morphological variation and over the last thirty years a USDA-ARS nursery has been established in Tifton, GA. Accessions have been collected worldwide and this study was conducted to assess the molecular genetic variation and genetic relatedness among 89 accessions using Amplified Fragment Length Polymorphisms (AFLP) markers. Using 225 polymorphic markers from eight selective primer combinations, the accessions were clustered into five groups using a principal components analysis (PCA) and a dendrogram based on DICE similarity estimates and unweighted pair group method with arithmetic average (UPGMA) clustering. These five groups include three groups collected from Kenya, a group for Puerto Rico, and accessions derived from the cultivar ‘Merkeron’ or collected by S.C Schank. This research provides the first molecular characterization of the nursery and provides potential heterotic groups for napier grass and pearl millet breeding improvement.