A taxonomic Study of Amygdalus L. by the traditional and modern methods in the middle area and the south-west area from Syria

The research was carried out in the laboratories of the Department of Renewable NaturalResources and the Environment, and the laboratories of the Biotechnology Department ofthe Faculty of Agriculture at Damascus University (Syria) during the years 2021/2020.The study was conducted on five species of wild almonds (Amygdalus/ Prunus) in severalmajor sites of its spread in the central and southern region of Syria, with the aim ofstudying the taxonomic importance of some morphological, anatomical and pollen traitsof the members of these species naturally scattered in Syria, as some morphological traitsof leaves, branches and fruits were studied. Some anatomical characteristics of youngwood were studied by studying the diameters of the transport vessels, as well as thediameters of the pollen grains.The results of the study showed that there were significant differences between thestudied species in their different locations with regard to inseqective, anatomical, andmorphological traits. The results of the morphological study also showed the discrepancybetween the studied samples belonging to these species, as they were divided into twoclusters, the first included two groups, the first included the two species of almonds,A.arabica and A.spartioïdes, the second included the two species A.korschinskii and theA.orientalis, while the second cluster included the A.communis species alone. The resultsof the anatomical and forensic study also largely matched the results of themorphological study. The study therefore proposes to follow up on the taxonomic workof the species, using other indicators, especially molecular ones.The gentic study was conducted on almond species spread in five main regions todetermine the degree of genetic relationship among them using the ISSR (Inter SimpleSequence Repeats) technique, 23 primers were used for this purpose, and 21 primers ofthem gave polymorphism among the studied species. The use of these primers resulted ina total of 95 bands, 93 of them were polymorphic, and the polymorphism ratio was96.51%. The number of polymorphic bands ranged between 2 bands with the primers (P-8 and P-15), and 6 bands with the primers (P-30, P-36 and P-37) with an average of 4.42bands for each primer, and the average polymorphic information content coefficientranged between 0.0525 with the primer P-8 and 0.4998 with the primer P-25, with anaverage of 0.4132. The percentage of genetic distance ranged between 46 and 92%, andthe lowest value was 46% between the two species, A. communis and A. korschinskii.This low value of genetic distance indicates a large degree of genetic relationship. Whilethe highest value of genetic divergence was 92% between the two species A.spartioïdesand A. arabica, which indicates that there is a large genetic variation between them. Itwas noted that the tree was divided into two main clusters, the A. orientalis genotype wasunique to the first cluster, while the second cluster included the other genotypes dividedinto two sub-clusters with varying degrees of genetic relationship. Our results indicate thepossibility of using the ISSR technique to study genetic relationship among wild almondcultivars.In order to study allelic variations of the genes that responsible for drought tolerance atthe level of DNA. The results of this investigation showed a clear difference in thesegenes between the studied species, where the polymorphism in the molecular weightbetween the isotopes of the one site were sometimes great sometimes, they were at a highdegree of similarity, and it was easily distinguished on the metaphor agarose gel 4%.Using PCR technology, 7 pairs of primers were used, all of which proved to be effectivethey resulted in 22 allele. The results showed that genes (ACC oxidase, SDH)outperformed the number of polymorphic patterns and gave 5 patterns in all studiedspecies, followed by the gene (SOT1( with 4 polymorphic patterns, while the genes(S6PDH, P5CS, GTL, SIP1) gave the lowest number of polymorphic patterns (2polymorphic patterns) with all Studied species. The results also showed the superiority ofspecies (A.arabica) by the number of polymorphic patterns wich gave 7 polymorphicpatterns, followed by species (A.orientalis, A.communis, A.spartioïdes) (4 polymorphicpatterns), while species (A.korschinskii) had given the lowest number of polymorphicpatterns (3 polymorphic patterns).