Assessment of genetic diversity among Jordanian wild barley (Hordeum spontaneum) genotypes revealed by SSR markers

Abstract

Wild barley, Hordeum spontaneum is the progenitor of cultivated barley. The center of diversity is in the Fertile Crescent in the Near East, where wild barley grows under a wide range of environmental and climatic conditions. Jordan wild barley is expected to harbor important genes that could be used for the improvement of the cultivated varieties especially in their tolerance to drought. To assess genetic diversity and allelic variation of Jordanian wild barley, 103 wild barley genotypes collected from different parts of Jordan along with 29 cultivated barley genotypes were analyzed for diversity by means of Simple Sequence Repeats (SSR). The spontaneum genotypes were grouped into six populations according to their longitude, latitude, altitude, and rainfall zone of the sites from where they have been collected, and the cultivated in one population. All barley genotypes were analyzed with 11 SSR markers with known sequences and chromosomal locations. The 11 microsatellite markers revealed 237 alleles, with an average of 21.5 alleles per locus. In spontaneum genotypes, 209 alleles were identified with an average of 19 alleles per locus, whereas, cultivated genotypes had 95 alleles with an average of 8.6 alleles per locus. Moreover, 52 alleles were identified in spontaneum (22 %) of the total alleles and 22 alleles in cultivated barley (9 %). The level of genetic diversity was very high; in fact, mean in total gene diversity (Ht) was 0.86 ranging from 0.72 to 0.94. Average gene diversity (H) was 0.79 ranging from 0.74 to 0.82. Genetic variation within population was much higher than among populations at molecular levels: this was also supported by the finding that morphological characters such as awn length, plant height, days to maturity, peduncle length, peduncle extrusion and tillering number, showed higher variation within populations than among populations. Clustering of populations was according to their ecological geographical pattern.

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

“…These variations showed some limitations such as phenotype modifications due to environmental influence, when compared with molecular markers (Ferreira, 2006). 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).…”

“…Most of the differentiation (95%) was present within accessions. This could be due to the natural selection and gene flow as it had been reported in many studies (Turpeinen et al, 2003;Nevo et al, 2004;Shakhatreh et al, 2015). According to Nevo et al (1998), natural selection appears to be a major differentiating and orienting force of regional evolutionary change, maintaining genetic polymorphisms under conditions of environmental heterogeneity and stress.…”

“…Among these, Single Sequence Repeat (SSR) or microsatellite markers, which target tandem repeats of ditri-or tetra-nucleotide DNA motifs, are both highly polymorphic within populations and randomly distributed throughout the genome in both transcribed and nontranscribed sequences (Saghai-Maroof et al, 1994;Manzelli et al, 2007). 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.…”

Forage pea (Pisumsativum var. arvense L.) landraces reveal morphological andgenetic diversities

“…The wide diversity observed in this region could be due to selection of unconsciously appropriate alleles by farmers with better adaptation to local climatic conditions. In pea, as in other organisms, selection appears to be a major differentiating and orienting force of regional evolutionary change, maintaining genetic polymorphisms under conditions of environmental heterogeneity and stress (Hübner et al, 2009;Shakhatreh et al, 2016). In the present study, except for two samples, no marker heterozygosity was detected, suggesting that these landraces were highly homozygous.…”

Two hydrazones derived from 1-aryl-3-(p-substituted phenyl)prop-2-en-1-one: synthesis, crystal structure, Hirshfeld surface analysis andin vitrobiological properties

“…They indicate that all compounds show only moderate activity. Many chalcones are known to exhibit reasonable antibacterial activity due to the presence of ,-unsaturated carbonyl groups that can enhance activity (Shakhatreh et al, 2016). Out of the various synthesized compounds, it is observed that chalcone (C1), with phenyl and p-methylphenyl moieties, proved to be the most effective against all strains with a zone of inhibition of 12 mm.…”