Geographical Ecological and Genetic Study of Some Arabian Almond Prunus Arabica (Olivier) Meikle Populations in the Syrian Steppesز

In the Syrian steppe, the Arabian almond (Prunus arabica) is one of the most drought and continental conditions-tolerant species related to genre Prunu . This species suffers from high degree of overgrazing reducing largely the area of its spread and threatening its existence which can be considered as a national and regional loss of biological patrimony.The populations of this species have been studied in its natural spread in the downer part of Al-loweizeh valley near Palmyra during 2010. Surface, dominant diameter and height, number of fruits and grazing intensity were measured in 114 groups of Arabian almond (population continues one or more groups and each group is constituted of many individuals having often the same stool) in the two sides of the valley along almost 2km.The genetic relative degree between many wild genotypes of the Arabian and the spartioid Prunusspartioides almond has been determined utilizing the ISSR technique.The results have showed small diameters and heights (1.04 cm for diameter and 57.5cm for height in average) with surfaces up to 15m2.The study have also showed that all the populations suffer from overgrazing (degree1), while the number of fruits by population was 6.5 fruits in average.Statistical analysis has showed a positive correlation (**) between the surface of the population in one side and the diameter and height in the other side. It has also showed a negative correlation (**) between the mean diameter and surface of the population and the distance from the valley, and a positive correlation (**) with the location of the population along the river (up or down).The study has showed a high degree of genetic diversity in the samples collected from the Syrian steppe (near Palmyra) and a genetic divergence between these samples and those collected in the country side of Damascus.The study has recommended the necessity to continue exploring the presence of Arabian almond in other sites especially in the valleys since this species is correlated to such a habitat and the importance of comprehensive protection of these populations. The study also highlighted the importance of further study of the genetic diversity of this species and its conservation.