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Session 1 – Evolution and Natural Variation
P1.3- Morpho-phenologic diversity among Tunisian populations of
Brachypodium Distachyon
Mohamed Neji, Sondes Rahmouni, Warda Saoudi, Malek Smida, Wael Tamaalli
Mounawer Badri, Chedly Abdelly and Gandour Mhemmed
Center of Biotechnology of Borj-Cédria, BP 901 hammam lif 2050 Tunisia
mnmedneji@gmail.com
Abstract
Brachypodium distachyon, commonly called ‘purple false brome’, belongs to Poacea
grass subfamily. This species is mainly distributed in South Europe, North Africa, Southwest
Asia and many other places. It is frequently diploid and has a small genome size
(300Mb). B. distachyon has a close genetic relationship with temperate cereal crops. In
order to bring a better knowledge on the genetic diversity of this species, 9 populations
of B. distachyon representative of all the eco-climatic stages of Tunisia were
characterized on the basis of 18 morpho-phenologic features. Data obtained for the 180
evaluated lines were subjected to various statistical analyses. It arises from the statistical
analyses significant variations for all studied features.
Correlations analysis shows that the majority of morphometric traits were negatively and
significantly correlated between them. The relative importance of the components inter
and intra-population of the phenotypical variation was different according to the
evaluated feature.
Relative importance of intra and inter-populations components variation for phenotypic
variation varied between traits.
Variation of spikelet emergence date, means number of enternode per stem, mean
length of leafs and shape number were dominated by the inter-populations component
but the remaining traits were dominated by the intra-populations component.
The similarities between populations were analyzed by a hierarchical classification. The
dendrogram obtained showed the presence of two principal groups, which reflect a
marked geographical structuring. The first grouped populations originated from (Fayadh
and Zagouan) and the second one grouped the remaining populations.
Keywords
B. distachyon; morphological diversity; geographical structuration
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