Genetic Diversity of Biofuel and Naturalized Napiergrass (Pennisetum purpureum)

Abstract

Biofuel crops such as napiergrass possess traits characteristic of invasive plant species, raising concern that biofuels might escape cultivation and invade surrounding agricultural and natural areas. Napiergrass biofuel types are being developed to have reduced invasion risk, but these might be cultivated in areas where naturalized populations of this species are already present. The successful management of napiergrass biofuel plantations will therefore require techniques to monitor for escaped biofuels as distinguished from existing naturalized populations. Here we used 20 microsatellite DNA markers developed for pearl millet to genotype 16 entries of napiergrass, including naturalized populations and accessions selected for biofuel traits. Use of the markers showed a clear genetic separation between the biofuel types and naturalized entries and revealed naturalized populations undergoing genetic isolation by distance. These findings demonstrated the utility of microsatellite marker transfer in the development of an important tool for managing the invasion risk of a potential biofuel crop.

Assessment of Genetic Diversity in Napier Grass (Pennisetum purpureum Schum.) using Microsatellite, Single-Nucleotide Polymorphism and Insertion-Deletion Markers from Pearl Millet (Pennisetum glaucum [L.] R. Br.)

“…Out of these, 85 accessions were also used by Harris et al (2009) for an AFLPbased diversity study, including three (N35, N37, and N75) by Azevedo et al (2012) and two (N13 and N43) by Lopez at al. (2014) in which microsatellite markers were employed.…”

“…Although several studies have been performed to assess genetic diversity in Napier grass using molecular markers such as RAPDs, isozymes, ISSRs, AFLPs, and SSRs (Lowe et al 2003;Bhandari et al 2006;Ganesh et al 2009;Harris et al 2009;Azevedo et al 2012, Lopez et al 2014, this work provides an expanded set of transferable pearl millet microsatellite, SNP, and indel markers in a genetic diversity study on Napier grass collections which are maintained at USDA, Tifton, GA, USA. There are many more pearl millet microsatellites and conserved intron-spanning primer (CISP) markers (Feltus et al 2006) for Pennisetum available (Budak et al 2003;Mariac et al 2006;Yadav et al 2007Yadav et al , 2008Rajaram et al 2013) which can be further tested for crossamplification in Napier grass and then utilized for further downstream studies.…”

“…The study showed clustering of accessions into five major groups which were well aligned with their geographical origins. Lopez et al (2014) reported the transferability and utilization of microsatellite markers developed for pearl millet to assess the genetic variability among a small set of 18 Napier grass accessions. The study showed a high rate of marker transferability and ability to characterize genetic variability among Napier grass accessions.…”

“…Recently, Azevedo et al (2012) reported genetic similarity estimates, using microsatellite markers among 107 Napier accession of the Embrapa Active Germplasm Bank of Napier Grass, Brazil (Embrapa-BAGCE). This study described here employed a different collection of germplasm accessions and microsatellite marker sets than Lopez et al (2014) and Azevedo et al (2012) and is the first extensive work to identify large sets of transferable pearl millet microsatellite markers to Napier grass and to use them in evaluating genetic diversity in a large number of Napier grass accessions nursery maintained at USDA-ARS, Tifton, GA, USA.…”

Phylogenetics and diversity analysis of Pennisetum species using Hemarthria EST‐SSR markers

“…The marker loci are probably homologous regions with similar alleles. Several studies have been performed to assess genetic diversity in Pennisetum species using molecular markers such as RAPDs, isozymes, ISSRs, AFLPs, and SSRs (Azevedo et al., ; Babu et al., ; Bhandari, Sukanya, & Ramesh, ; Harris, Anderson, & Malik, ; López et al., ; Lowe, Thorpe, Teale, & Hanson, ), and this study provided an expanded set of transferable EST‐SSR markers from other genus in a genetic diversity study on Pennisetum collections.…”