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Low Genetic Differentiation and Evidence of Gene Flow among Barley Landrace Populations in Tunisia
Author(s) -
Ben Romdhane Mériam,
Riahi Leila,
Selmi Ayet,
Jardak Rahma,
Bouajila Aida,
Ghorbel Abdelwahed,
Zoghlami Nejia
Publication year - 2017
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2016.05.0298
Subject(s) - biology , genetic diversity , hordeum vulgare , microsatellite , genetic variation , gene flow , locus (genetics) , gene pool , population , genetic variability , ex situ conservation , allele , in situ conservation , genotype , agronomy , poaceae , genetics , gene , demography , sociology
Tunisian barley ( Hordeum vulgare L.) landraces, representing the oldest cultivated accessions, are growing in scattered populations across drought‐ and salt‐stressed environments and constitute a precious reservoir of potentially useful traits for breeding programs. The objective of this study was to elucidate genetic diversity and population structure of barley landraces across the landscape of Tunisia. Populations from 11 geographic zones were genotyped using 21 nuclear microsatellites. A high level of genetic polymorphism with 170 detected alleles was recorded among the studied genotypes. The average allelic richness was 8.095 alleles per locus. The index of genetic diversity ( H e ) showed an average of 0.741. Genetic diversity was very high within populations, whereas differences among populations were difficult to detect. Only 0.15% of the DNA variation was apportioned among landraces ( P < 0.001), whereas 99.85% of the DNA variation was maintained within these landraces. A high gene flow (Nm) was revealed among the investigated populations, which has been facilitated by exchange of barley seeds between Tunisian cereal farmers of different regions. Genetic diversity within Tunisian barley landrace germplasms may help to maintain adaptation to a broad range of environmental conditions and provide genetically diverse resources for barley breeders. Both ex situ (seed banks) and in situ (on‐farm) conservation strategies may be required to maintain barley landrace genetic resources.