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

Abstract

The understanding of genetic diversity within local crop varieties constitutes an important step in the preservation of their genetic potential. The objective of this study was to assess the genetic diversity of sorghum (Sorghum bicolor (L.) Moench) cultivated in the Northwest of Benin and to reveal certain fundamental evolutionary mechanisms. A total of 61 accessions of sorghum landraces belonging to the four identified races in Benin were estimated using 20 microsatellite markers. For all the loci analyzed, 140 polymorphic alleles were detected with a mean value of 7.00 per locus and polymorphic information content (PIC) average value was 0.33 for all the 20 simple sequence repeats (SSRs), suggesting an important genetic diversity within the cultivated sorghum germplasm used. An unweighted pair group method arithmetic average (UPGMA) clustering and principal coordinate analysis (PCoA) based on DICE coefficient revealed three major genetic groups supported by two main components: the botanical race and the morpho-physiological characteristics of the grains (colour and degree of bitterness). It was thus recommended that further research on genetic diversity of sorghum should integrate these genetic parameters for a better preservation of the genetic resources of this important crop in Benin.

Characterization of Coloured Sorghum Genotypes for Qualitative and Quantitative Characters

“…The pigmentation is indication of phenolics are known to provide defense against biotic mainly against shoot fly and abiotic stresses in plants (Dixon and Paiva, 1995). Similar studies were reported by Sangwan et al (2005) for panicle compactness and shape of panicle, Elangovan et al (2009) and Missihoun et al (2015) for inflorescence compactness and shape and glume colour (Figure 3).…”

Genetic diversity analysis of sorghum [Sorghum bicolor (L.) Moench] races in Ethiopia using simple sequence repeats (SSR) markers

“…Similar findings by Cuevas and Prom ( 2013), and to a certain extent Agrama and Tuinstra (2003) also reported average PIC values 0.78 and 0.622, respectively. However, the observed PIC value is higher than that of Geleta et al (2006), Antoine et al (2015) and Catherine et al (2016) who reported 0.46, 0.33 and 0.49, respectively. This may be the result of low numbers of accessions considered in their studies and sample collections represented are from specific areas of agroecologies.…”

“…Qualitative and quantitative studies, in addition to RAPD, AFLP and SSR markers utilized by different scholars also revealed the same amounts of variations among their collections (Ayana and Bekele, 1998;Geleta et al, 2006;Cuevas and Prom, 2013). SSR marker studies from Eritrean, Eastern Kenya, Benin and Zambia collections also showed presence of wide genetic diversity of sorghum bicolor in Africa mainly in Eastern regions (Tesfamichael et al, 2014;Catherine et al, 2016;Antoine et al, 2015;Ng'uni et al, 2011). The existence of imbalanced sorghum races in the sample collections of the different studies from Ethiopia might contribute to the overall observed genetic variation (Cuevas and Prom, 2013).…”

“…Ethiopian Biodiversity Institute (EBI) collected large numbers of farmers' landraces though they do not have a racial category. Antoine et al (2015) also recommended research on genetic diversity to integrate both botanical races and morpho-physiological characteristics of the crops for better preservation of sorghum genetic resources. In addition, morphological studies involving germplasms from Ethiopia and Eritrea show the greatest share of variation observed were carried by their panicle compactness and shape, which is 31% (Ayana and Bekele, 1998).…”