Genetic structure among sorghum landraces as revealed by morphological variation and microsatellite markers in three agroclimatic regions of Burkina Faso

Abstract

Diversity among 124 sorghum landraces from 10 villages surveyed in 3 regions of Burkina Faso covering different agroecological zones was assessed by 28 agromorphological traits and 29 microsatellite markers. 94.4% of the landraces collected belonged to the botanical race guinea (consisting of 96.6% guinea gambicum and 3.4% guinea margaritiferum), 74.2% had white kernels, 13.7% had orange and 12.1% had red kernels. Compared to the "village nested within zone" factor, the "variety nested within village within zone" factor predominately contributed to the diversity pattern for all nine statistically analysed quantitative traits. The multivariate analyses performed on ten morphological traits identified five landrace groups, and of these, the red kernel sorghum types appeared the most homogenous. 2 to 17 alleles were detected per locus with a mean 4.9 alleles per locus and a gene diversity (He) of 0.37. Landraces from the sub-Sahelian zone had the highest gene diversity (He = 0.38). Cluster analysis revealed that the diversity was weakly stratified and could not be explained by any biophysical criteria. One homogenous guinea margaritiferum group was distinguished from other guinea landraces. The red kernel type appeared to be genetically distinct from all other guinea landraces. The kernel colour was the principal structuring factor. This is an example of a homogeneous group of varieties selected for a specific use (for local beer preparation), mainly grown around the households in compound fields, and presenting particular agromorphological and genetic traits. This is the most original feature of sorghum diversity in Burkina Faso and should be the focus of special conservation efforts.

Genetic diversity of Sorghum bicolor (L.) Moench landraces from Northwestern Benin as revealed by microsatellite markers

“…Before the advent of GBS-based single nucleotide polymorphism (SNP) markers and additionally other whole-genome profiling markers (for example DArT), microsatellite markers are the most used worldwide in the characterization of sorghum genetic resources and particularly in genetic diversity analysis (Smith et al, 2000;Folkertsma et al, 2005;Barnaud et al, 2007;Deu et al, 2008;Barro-Kondombo et al, 2010;Bhosale et al, 2011). In Benin, although AFLP markers were used in genetic characterization of sorghum local varieties (Kayodé et al, 2006), it is the first time SSR markers were used for sorghum germplasm analysis.…”

“…Genomic sorghum SSR markers used in this study belonged to the linkage maps of sorghum published by Taramino et al (1997), Bhattramakki et al (2000) and Kong et al (2000) which were recently used by Shehzad et al (2009), Barro-Kondombo et al (2010 and Bhosale et al (2011). Thirty six (36) SSR primers were initially tested on four sorghum accessions and finally, 20 genomic sorghum SSR markers were selected based on their high polymorphic information content (PIC) value observed on the previous studies on African sorghum Landraces.…”

“…Microsatellite markers have been developed and largely used in sorghum during more than a decade (Brown et al, 1996;Taramino et al, 1997;Schloss et al, 2002;Barnaud et al, 2007;Barro-Kondombo et al, 2010). They are multi-allelic, codominantly inherited, locus specific, easily detected by polymerase chain reaction (PCR) and require only a small amount of starting DNA (Powell et al, 1996).…”

Genetic diversity among sorghum landraces and polymorphism assessment of local improved varieties for stay-green trait

“…Among the world's cereals, it ranks fifth in annual tonnage [Food and Agriculture Organization of United Nations (FAO), 2015]. It constitutes the major cereal and food crop for rural population in Burkina Faso where traditional varieties (landraces or local accessions) are dominant in the traditional cropping system, with a preponderance of the Guinea botanical race (Barro-Kondombo et al, 2008). Traditional varieties are important genetic resources, their conservation would maintain genetic diversity and their valorization would ensure food security (Missihoun et al, 2012).…”

Genetic diversity assessment in sorghum accessions using qualitative morphological and amplified fragment length polymorphism markers

“…Grenier et al (2004) observed the morphological diversity among sorghum accessions as well as a high level of diversity within each region and was distributed with geographical origin using 2 017 Sudanese sorghum landraces. Barro-Kondombo et al (2010) also found a high level of morphological and genetic variability in sorghum varieties from Burkina Faso.…”