Genetic Relationships among Aegilops L. Species Using DNA Molecular Markers

Ensherah M. Nazir Al-AHMAR
General Commission for Scientific Agricultural Research-
Gene Bank Division, Syria
Faculty of Agriculture, Damascus University,
2010

Abstract

A number of genetic accessions were collected from different Syrian ecological regions and characterized by morphological and molecular approaches to study the genetic relationship between them. The study material consisted of 175 genetic accessions belonging to Aegilops genera. The genetic accessions were planted at GCSAR’s Karahta station for field crops research, 30 km to the east-southern of Damascus city, 633 m above sea level during the two growing seasons 2004 and 2005. Twelve morphological traits were studied:
number of days needed for germination, number of days needed for tilleringe, number of days needed for heading, number of days needed for maturity, plant height, number of fertile tillers, spike length, number of spikelets per spike, leaf height, leaf width and grain weight per plant. The results showed that there were significant differences between species for all traits under study, whereas the two species Ae. speltoides, Ae. tauschii had early germination with an average of 31.67 and 33.00 days respectively; they were the earliest in maturity, while the species Ae. vavilovii had late germination on an average of 43.00 days. As for heading, the species of Aegilops section were late in heading, whereas the species Ae. neglecta had the highest value (late heading) with an average of 169.3 days, while the species Ae. speltoides had early heading on an average of 126.7 days. The species Ae. biuncialis had the highest value in terms of number of fertile tillers per plant (79.67 fertile tillers), the species of Aegilops section were superlative in this trait and they were superlative in plant height too, whereas the highest value average was for  Ae. triuncialis species (52.00 cm). As for leaf height trait, the species of Vertebrata section were superlative, whereas their means of leaf height were the highest comparing with other studied species, the mean of leaf height (cm) was the highest for the species Ae. crassa (18.00 cm) then the species Ae. vavilovii with an average of 14.37 cm. The average values of the species belonging to the section Vertebrata where the highest comparing with studied species for grain weight trait per plant. The results of finger printing showed good genetic dissimilarities and genetic variations between studied species, whereas the disagreement values (PDVs) ranged between 0.27 and 0.37.  The genetic relationship tree diagram analysis demonstrated that the two species Ae. kotschyii and   Ae. peregrina were the closest genetically, followed by the two species Ae. biuncialis and Ae. ovata, however, Ae. tauschii and  Ae. speltoides are the genetically farthest from the other species, which were at the same time the closest species of the indicator species T. aestivum, which were separated from rest of studied species. The 12 species were accumulated in two separated clusters; the first cluster consisted of two species Ae. searsii and Ae. vavilovii (sister species) and the second consisted of the other ten species which are belonging to the section Aegilops, except for the two species Ae. caudata from section Cylindropyrum and Ae. crassa from section Vertebrata, they were the farthest species in this cluster. The tree diagram showed also the two species Ae. columnaris and  Ae. neglecta as sister species. The same thing was noticed for the two species: Ae. columnaris and Ae. peregrina, Ae. triuncialis and  Ae. umbellulata.