Résumé:
In the setting of one survey carrying polymorphism heterohromatic at
some varieties of cultivated wheat in Algeria ; a particular attention was carried
to the differential staining with Giemsa (or C-banding) putting the constitutive
heterochromatin correspondent in evidence to some repeated sequences of ADN.
The obtained results allowed us to identify the'genomes A and B of three
varieties of durum wheat (T durum DESF.), and the genomes A, B and D of two
varieties of common wheat (T aestivum L.). the genomes A and D were less
heterochromatic ; however the genomes B were highly heterochromatic.
Since it exist a heterochromatic variability among varieties in species
T. durum DESF. The cytogenetic analysis of three varieties (Bidi 17, Waha, OuedZenati) reveals a numerous variations : The variety Oeud-Zenati showed
overloading in heterochromatin (intensity and number of C bands) compared to' '
reference variety of Langdon. This results were on the contrary of that of Bidi 17
and Waha varieties ; where Waha variety was moderathly heterochromatic ;
whereas Bidi 17 variety reveals less heterochromatin. This study allowed to
establish a translocation occurrence in 1BL / IRS in Waha variety.
Moreover : the cytogenetic study performed on two varieties of
T aestivum L. Showed a heterochromatic variability ; That is Tessalah variety
was poor in heterochrometin compared to Chinese Spring reference variety ;
however, Ziad variety was rich in heterochromatin. The variations put in
evidence in the two varieties indicated the presence of polymorphism
heterohromatic.
All the chromosomes wich carry the additional C bands are chromosomes
rr
‘s markers.
Therefore ; the obtained results allow us to advance the relation
hypothesis existing between the heterochromatin abundance of Oued-Zenati and
its adaptation to the difficult climate conditions.