Patterns of molecular and phenotypic diversity in pearl millet [Pennisetum glaucum (L.) R. Br.] from West and Central Africa and their relation to geographical and environmental parameters

Abstract

BackgroundThe distribution area of pearl millet in West and Central Africa (WCA) harbours a wide range of climatic and environmental conditions as well as diverse farmer preferences and pearl millet utilization habits which have the potential to lead to local adaptation and thereby to population structure. The objectives of our research were to (i) assess the geographical distribution of genetic diversity in pearl millet inbreds derived from landraces, (ii) assess the population structure of pearl millet from WCA, and (iii) identify those geographical parameters and environmental factors from the location at which landraces were sampled, as well as those phenotypic traits that may have affected or led to this population structure. Our study was based on a set of 145 inbred lines derived from 122 different pearl millet landraces from WCA.ResultsFive sub-groups were detected within the entire germplasm set by STRUCTURE. We observed that the phenotypic traits flowering time, relative response to photoperiod, and panicle length were significantly associated with population structure but not the environmental factors which are expected to influence these traits in natural populations such as latitude, temperature, or precipitation.ConclusionsOur results suggested that for pearl millet natural selection is compared to artificial selection less important in shaping populations.

Assessment of genetic diversity among cultivated Pearl millet (Pennisetum glaucum, Poaceae) accessions from Benin, West Africa

“…The SSR molecular markers are known to be efficient for genetic diversity studies of pearl millet (Mariac et al, 2006;Bashir et al, 2015;Shakhatreh et al, 2015). The current study showed a lower average (4.071) number of alleles per locus compared to that reported by Mariac et al (2006) which was 6.2 for 421 cultivated accessions from Niger, and 16.4 for accessions from a wide geographic range in West and Central Africa (Stich et al, 2010). Other authors reported the analysis of 214 Sudanese pearl millet accessions in which they found a high level of alleles was reported with an average of 13.3 per locus (Bashir et al, 2015).…”

“…Overall, 22 Beninese pearl millet accessions have been sampled as part of larger studies targeting landraces spanning Western and Central Africa (Haussmann et al, 2006;Stich et al, 2010), and stored in the international genebank. However, these population is insufficient to provide information of their genetic diversity.…”

“…SSR markers have been successfully used to evaluate genetic diversity in several crop species such as wheat (Fufa et al, 2005), Pennisetum purpureum (Azevedo et al, 2012), Capsicum (Nicolai et al, 2013), Sorghum (Cuevas et al, 2014), barley (Shakhatreh et al, 2015), Vigna subterranea (Molosiwa et al, 2015), maize (Salami et al, 2016) and some underutilized species such as buckwheat and wild melon (Roy et al, 2012;Zhang and Zao, 2013). For pearl millet characterization, several SSR markers were developed (Mariac et al, 2006;Stich et al, 2010;Nepolean et al, 2012) and used to evaluate its genetic diversity at the regional scale in west Africa. In the Stich et al (2010) study, it has been proposed that Western and Central Africa (WCA) are the primary center of origin and genetic diversity of pearl millet.…”

“…For pearl millet characterization, several SSR markers were developed (Mariac et al, 2006;Stich et al, 2010;Nepolean et al, 2012) and used to evaluate its genetic diversity at the regional scale in west Africa. In the Stich et al (2010) study, it has been proposed that Western and Central Africa (WCA) are the primary center of origin and genetic diversity of pearl millet. Moreover, with respect to Beninese accessions, few of them (22 accessions) were included in the 2010 study since the country is regarded as a secondary centre for pearl millet production.…”

Molecular characterization of pearl millet [Pennisetum glaucum (L.) R. Br] inbreds using microsatellite markers

“…The two polymorphic primers were used for cluster analysis. In previous studies, Stich et al (2010) observed more number of alleles per locus, while analyzing diversity in germplasm lines. Similarly, Kapila et al (2008) found an average of 6.26 alleles per locus, in a set of maintainer lines.…”